الاثنين، 19 سبتمبر، 2011

Dog diseases caused by virus


What is a virus?
A virus is a sub-microscopic particle that ranges from 20 to 300 nanometres in size. It can infect the cells of a biological organism, such as a human or a dog, and cause anything from mild discomfort to serious, lethal disease. Viruses need to infect a host cell in order to multiply and can therefore not replicate without a suitable host.

Viruses causing dog disease
A lot of well known dog diseases are caused by viruses, such as canine distemper, canine parvovirus disease, canine coronavirus disease, canine influenza, canine herpesvirus, canine minute virus, infectious canine hepatitis, kennel cough (can also be caused by bacteria), rabies, and pseudorabies. As you can see; virus diseases in dogs stretches from milder cases of kennel cough to diseases with an exceptionally high death rate like rabies and canine distemper.

Virus and antibiotics
Many different dog diseases are caused by viruses, and unfortunately antibiotics will not help if your dog gets infected with a virus. Some people – including dog owners – have a strong tendency to retort to antibiotics as soon as they feel ill, and irresponsible doctors and veterinarians sometimes let them have their way. If your dog comes down with a virus, demanding antibiotics is a bad idea for several reasons:

Antibiotics will not cure or milder dog diseases caused by viruses.
Antibiotics can cause side-effects. Now your dog has to combat a viral infection and antibiotics side effects simultaneously.
Over-use of antibiotics increases the risk of antibiotic resistance development in bacteria. The more antibiotics we use, the greater the risk of cultivating bacteria that will be immune or highly resilient to antibiotics.
There are however situations where the initial viral infection opens up the way for bacteria. A common Kennel cough (similar to a human cold) can for instance lead to pneumonia in dogs, just like a cold can develop into pneumonia in humans. If this happens, antibiotics should naturally be administered since the secondary infection is caused by bacteria and not by a virus.

Virus vaccination for dogs
The best way of keeping your dog healthy is to vaccinate it against common viruses. A vaccine will produce immunity and make it possible for the immune system of your dog to successfully combat the virus from day one. The exact length of the immunity period varies; contact your veterinarian for more specific information. In many countries, vaccination of dogs is mandatory for serious diseases, such as rabies and canine distemper.

Anti-virus treatment for dogs
As mentioned above, giving your dog antibiotics will not help it if it has been infected with a virus. There are a few antiviral drugs available for dogs, but they are not a quick-fix for any type of virus. For some viruses an antiviral drug will work like a charm, but for many others there is still no cure. In many cases, the veterinarian will instead focus on helping your dog's immune system combat the virus. The veterinarian can for instance give your dog IV fluids to prevent dehydration, give it extra blood plasma from a donor, and keep the fever down if it starts to rise to dangerous levels. The vet can also make your dog feel better by giving it painkillers, cough medicine and so on, depending on the symptoms.

Virus infections in dogs: (click for more info)
Canine coronavirus in dogs
Canine distemper in dogs
Canine herpesvirus in dogs
Canine influenza in dogs
Canine minute virus in dogs
Canine parvovirus in dogs
Infectious canine hepatitis in dogs
Kennel cough in dogs
Pseudorabies in dogs
Rabies in dogs

Canine parvovirus


Canine parvovirus is a contagious virus infection that mainly affects puppies. It produces gastrointestinal (and sometimes cardiac) problems and can be lethal, especially for puppies. The canine parvovirus (CPV) is highly infectious and your dog doesn’t even have to meet an infected dog to catch it since it can spread via faeces. The canine parvovirus occurs all over the world.

The canine parvovirus wasn’t recognized until 1978, and the disease seems to have appeared in the 1970s. If the virus actually developed then or if there is some other reason why it wasn’t recognized until then is yet not known. What we do know is that by 1980 it had been found all over the world. It might be a mutated feline distemper parvovirus, but the experts still do not know for sure. The canine parvovirus is very similar to the feline distemper parvovirus; the only difference is two amino acids found in the capsid protein VP2. The canine parvovirus can also be mutated form of some other less known parvovirus, perhaps the feline parvovirus (FPV) or a parvovirus found in wild mammals.

There exist several identified strains of canine parvovirus, including CPV2a, CPV2b and CPV2c (a Glu-426 mutant). If your dog gets a normal routine test it will normally not be possible to tell exactly which strain that has infected your dog.

CPV infections in dogs

CPV comes in two forms; the intestinal form and the cardiac form. The cardiac form is rare in countries where vaccination of breeding dogs is common, since it develops in puppies that receive the parvovirus in uterus or shortly after being born. Cardiac CPV can lead to sudden heart failure; usually before the puppy reaches an age of eight weeks. The heart failure is caused by parvovirus attacking and destroying the heart muscle.

The intestinal form of canine parvovirus enters the dog via its mouth, e.g. through faeces, infected soil or shared toys. It will then infest the lymphoid tissue in the throat, where it multiplies before spreading to the bloodstream. The canine parvovirus is known to attack cells that divide them selves rapidly in the dog, such as the cells found in bone marrow, lymph nodes and intestinal crypts. This weakens the immune system of the dog and can make it possible for bacteria that normally inhabit the intestines to enter the bloodstream where they cause sepsis. An infected dog can release parvovirus through its faeces for up to 3-4 weeks after being infected. Some dogs become asymptomatic carriers that regularly spread the virus without showing any signs of illness.

CPV vaccination for dogs
Really young puppies can be protected by antibodies from their mother, especially if they nurse. Unfortunately, the effects of these antibodies often wear off before the immune system of the puppy is capable of handling the canine parvovirus. Most veterinarians recommended giving puppies a long series of vaccine shots, from the time that the anti-bodies from the mother starts to wear off to a point in time when the effect of these anti-bodies are definitely gone.

Canine parvovirus and certain breeds
Some breeds seem to be more inclined to CPV than others. Examples of such breeds are the Labrador Retriever, Rottweilers, Pit bull terriers, and Doberman Pinschers.

CPV treatment and medicine
The exact treatment will depend on how early the disease is diagnosed, and which type of CPV your dog develops. In sever cases, hospitalization can be necessary. In milder cases, home treatment with IV fluids and colloids can be enough. IV fluids are often combined with antibiotic injections, e.g. cefoxitin, timentin, metronidazole, or enrofloxacin. Anti-nausea injections (antiemetics) can also be necessary, e.g. metoclopramide, ondansetron, dolasteron, or prochlorpromazine. Severe protein loss in dogs can be treated with fresh frozen plasma and transfusions of albumin from a human. A transfusion of blood plasma from a donor dog that has successfully combated CPV in the past can give passive immunity. If you cannot find a suitable dog, you can purchase frozen serum. Anecdotal evidence indicates that oseltamivir (Tamiflu) might be able to limit the ability of the canine parvovirus to invade the crypt cells of the dog, but this has not been confirmed.

Vaccinating dogs against canine parvovirus is extremely important



Canine distemper


Canine distemper is a feared dog disease that can prove fatal. It is a viral disease caused by a member of the virus genus Morbillivirus. This virus can not only attack members of the familiy Canidae (dogs, wolves, foxes, coyotes, dingoes, jackals and lycaons), but Mustelidae (weasels), Mustelidae (skunks), and Procyonidae (raccoons) as well. It might also be capable of infecting certain members of the cat family Felidae, but has not been seen in domestic cats. Feline distemper, a disease affecting domestic cats, is caused by a different virus.

Canine distemper transmission
The canine distemper virus (CDV) is highly contagious and spread through the air. It can also be spread via infected bodily fluids, and is sometimes spread through water and food that has been contaminated with such fluids. The incubation time is normally 14-18 days, but can be as short as 3-6 days.

Canine distemper symptoms in dogs
The canine distemper virus (CDV) targets lymphoid, epithelial and nervous tissue cells, and can therefore cause a long row of symptoms. This disease is fairly often the cause of encephalitis with demyelination, interstitial pneumonia, and hyperkeratosis of the foot pads of the dog. By attacking the lymphoid, the virus weakens the immune system of the dog and makes it prone to a wide range of secondary infections. These are a few examples of symptoms that can be caused by canine distemper:

Discharge from the nose
Cough
Dullness of the eye
Redness of the eye
Tooth enamel hypoplasia
Thickened footpads
Vomiting
Diarrhoea
Fever
Shivering
Seizures
Loss of appetite
Loss of energy
Weight loss

Canine distemper diagnosis
If the symptoms are not enough to make a clear diagnosis, the veterinarian can search for the virus in the dog's conjunctival cells to obtain a definitive diagnosis.

Canine distemper prevention
The best way of preventing canine distemper is to have your dog vaccinated. There exists a selection of vaccines that will protect dogs as well as other animals, including domestic ferrets, from canine distemper and having your pet vaccinated is strongly recommended. In many countries, it is even mandatory. Keep in mind that there is no specific treatment for canine distemper once your dog is infected; the vet can only milder the symptoms and treat secondary infections, and a lot of dogs die from canine distemper each year. It is important to have a qualified veterinarian select the vaccine for you, because if you get a vaccine type that is not approved for use on dogs it can make your dog ill instead of protecting it.

When a dog or any other animal develops canine distemper, it should be quarantined. In many countries, not quarantining your dog will be illegal.

Disinfectants and detergents will kill the canine distemper virus, and so will drying out. This virus cannot survive more than a few hours at room temperature (20-25° C). It can however survive for several weeks outdoors where the temperature is slightly above freezing.

Canine distemper treatment
There is no specific cure for canine distemper and the vet can only focus on trying to milder the symptoms in your dog and preventing dehydration. Infected dogs are normally given intravenous fluids and nutritional supplements. The vet can also use antibiotics to treat secondary infections. Even when provided with qualified vet care, many dogs die from canine distemper



Canine coronavirus


Canine coronavirus is a gastrointestinal disease in dogs. Adult dogs normally develop mild symptoms or no symptoms at all, while puppies can develop severe symptoms. The canine coronavirus belongs to the family Coronaviridae and is found in dogs all over the world. It was first discovered in the early 1970s after an outbreak of the disease had occurred in watch dogs in Germany.

Canine enteric coronavirus
When a dog gets infected with the canine enteric coronavirus, the viruses moves to the villi of the small intestine where they multiply. The symptoms are usually mild, but can be severe for puppies and/or dogs simultaneously infested with canine parvovirus.

In the family Coronaviridae you can find a wide range of different corona viruses; many of them capable of affecting not only dogs but other mammals and birds as well. A majority of the diseases caused by corona viruses is mild and not dangerous, but there are exceptions. The feared virus behind SARS – Severe Acute Respiratory Syndrome - is for instance a corona virus. Coronaviruses that causes enteric infections can also be dangerous for young creatures, including young puppies and young human infants.

The new canine respiratory coronavirus
During recent years, a new type of canine coronavirus has been discovered. They are referred to as canine coronavirus Group II and can cause respiratory disease in dogs – Canine Respiratory Coronavirus (CRCoV). This type of virus is similar to strains from bovine and human coronaviruses (strain OC43. Canine coronavirus Group II was first isolated in the United Kingdom, and has now been found in dogs living on the European mainland, the United States, Canada, and Japan. The strain in United Kingdom was discovered in 2003, but a new study has indicated that the virus strain might have been present in Saskatchewan as early as 1996.

Canine coronavirus transmission and control
The canine enteric coronavirus is highly contagious and spreads through faeces. Infected dogs normally have the coronavirus in their faeces for 6-9 days, but some individuals keep spreading viruses for up to 6 months. Most types of disinfectants will kill the canine coronavirus. Since puppies are more sensitive to the canine coronavirus, it is a good idea to have your puppy vaccinated. If a high degree of all puppies in an area gets vaccinated it will also decrease the instances of canine coronavirus since there will be fewer available disease carriers. Vaccinating your dog is especially important if it will meet a lot of other dogs, e.g. because it is a show dog or competing agility dog.

Canine coronavirus symptoms
The incubation period for canine coronavirus is short; normally 1-3 days. Common canine coronavirus symptoms are diarrhoea, vomiting and loss of appetite. To be sure, the vet can test the faeces. Fatalities do occur, but they are rare.

Canine coronavirus treatment
In most dogs, especially adult and otherwise healthy dogs, ordinary diarrhoea treatment and care will be enough during a canine coronavirus infection. Severely affected dogs may however need intravenous fluids to prevent dangerous dehydration.


Canine herpesvirus


Canine herpesvirus (CHV) can cause a severe and often fatal hemorrhagic disease in puppies. The mortality rate is very high for puppies less than three weeks old. If the puppy is less than a week old, the mortality rate is around 80 percent. If the puppy is 3-5 weeks old, it has a much greater chance of survival but it can still develop a latent infection that causes future health problems. In adult dogs it is seldom lethal, but it is a sexually transmitted disease that can cause reproductive problems.

Canine herpes virus background
The canine herpesvirus was discovered during the 1960s. It is today known to occur in England, Germany, the United States, Canada, Japan and Australia.

Canine herpesvirus in puppies
If the mother is infected by CHV, she can transmit the disease to her puppies via the birth canal. The puppies can also contract the disease from oral and nasal secretions from the mother or other infected dogs that are allowed to come close to the puppies. CHV is not transmitted through the air.

The CHV virus seek out the surface cells of the tonsils, pharynx and the nasal mucosa. They will start to multiply rapidly and eventually spread to the rest of the body. A low body temperature makes it even easier for the virus to spread.

CHV symptoms in puppies
Crying
Depression
Weakness
Loss of sucking reflex
Soft yellow faeces
Discharge from the nose

The canine herpes virus can also lead to necrotizing vasculitis which can cause hemorrhage around the blood vessels in the puppy. Sometimes it is possible to see bruises on the belly, and eye problems such as uveitis, keratitis, reinitis, retinal dysplasia, and optic neuritis can set in.

< 1 week of age
If the puppy is less than one week old, it will usually die within one or two days after showing the initial symptoms.

3-5 weeks of age
If the puppy is 3-5 weeks old, CHP normally gets less severe since the puppy can maintain its body temperature and even develop a fever (the increased temperature makes it more difficult for the virus to spread).

A surviving puppy can develop a latent CHP infection, and some puppies develop neurological problems, including blindness and trouble walking properly. If the dog is subjected to stress or is given immunosuppressive drugs it can cause a latent CHP infection to become reactivated.

Canine herpesvirus in adult dogs
An infected dog can release the virus in secretions from the reproductive organs (vaginal or penile secretions), and sometimes raised sores can be seen on the reproductive organs. The CHP is therefore a sexually transmitted disease among dogs. As mentioned above, the disease can also be transmitted to puppies during or after birth, and through discharge from the nose.

Canine herpesvirus can cause Kennel cough.

If the mother is infected with CHV, it can lead to infertility, miscarriages and stillbirths.

Canine herpesvirus vaccine
In Europe, a vaccine named Eurican Herpes 205 has been available since 2003. This vaccine is administered to the female dog twice; the first time during heat or early pregnancy and the second time 1-2 weeks before its time for her to give birth to the puppies.

Canine herpesvirus treatment
There is no cure for dog herpes, but keeping the puppy warm can help it survive. Some veterinarians have achieved success by injecting antibodies to CHV into the abdomen of diseased puppie



Canine influenza


Canine influenza, commonly referred to as dog flue, is caused by varieties if the Influenza A virus capable of creating influenza in dogs and other canines. Among these varieties, the qquine influenze virus H3N8 is generally considered to be the most important one.

During an outbreak of H5N1, a completely different type of influenza, a dog in Thailand caught the disease by eating an infected duck. (H5N1 is also known as avian flu.)

Canine influenza background
The H3N8 influenza virus was discovered in 2004 after an outbreak on a racetrack in Florida. The virus is believed to have spread from horses to Greyhounds, since both animals competed on the same tracks. This was the first time in history that influenza A could be scientifically proven as causing influenza in dogs. Further investigations of serum taken from racing Greyhounds between 1984 and 2004 did however show dogs infected with canine influenza virus (CIV) as far back as 1999.

By analysing the genome of the canine influenza virus, scientists have confirmed that H3N8 was transmitted from horses to dogs and then adapted to dogs through point mutations in the genes.

Since influenza A has not occurred in dogs until the end of the 20th century (at least as far as we know), dogs have no natural immunity. When the virus enters a group of dogs, e.g. on a dog show, it normally spreads very quickly and a lot of dogs become infected. Thankfully, very few of the infected dogs die – especially not if they receive treatment for the secondary infections that can develop.

The influenza A virus is a enveloped negative sense single-stranded RNA virus. It is roughly 80-120 nanometres wide and 200-300 nm long. There are no known instances where canine influenza has spread from a dog to a human, a cat, or a horse.

Dog flu symptoms
When dogs become infected with canine influenza, roughly 80 percent of them develop noticeable symptoms. The incubation time is 2-5 days. A majority of the dogs develop only mild symptoms, but there are exceptions. Dog influenza can for instance lead to pneumonia (normally accompanied by high fever).

These are the most common symptoms of canine influenza in dogs:
- A cough that lasts for 10-30 days
- Greenish nasal discharge
- Fever

Canine influenza diagnosis
For a definite diagnosis, the vet can take a serum sample from the dog and send it to a laboratory that carries out a PCR test for canine influenza viruses. In many cases, upper respiratory disease in a dog proved to be vaccinated against the major causes of kennel cough will make the vet suspect canine influenza, especially if other dogs in the area has been diagnosed with it.

Canine influenza prevention
Unfortunately, there is no canine influenza vaccine available. Research indicates that a canarypox-vectored vaccine for equine influenza virus might be useful, but much more studies and tests are necessary.

The viruses behind canine influenza can be easily killed with common disinfectants, e.g. household bleach solutions.

A dog suffering from canine influenza should ideally be separated from other dogs, because it can release viruses for 7-10 days after showing the first symptoms. There are no known instances where a dog has become a persistent carrier of the disease.

Canine influenza treatment
There is no cure for canine influenza and the vet can only focus in alleviating the symptoms. If secondary bacterial infections set in, antibiotics can become necessary. If the dog develops pneumonia, the survival chance can be lower than 50% if you do not take it to a vet and provide it with correct care. Autopsies performed on dogs that died after having contracted canine influenza showed that they had developed severe hemorrhagic pneumonia and/or vasculitis





Canine influenza


Canine influenza, commonly referred to as dog flue, is caused by varieties if the Influenza A virus capable of creating influenza in dogs and other canines. Among these varieties, the qquine influenze virus H3N8 is generally considered to be the most important one.

During an outbreak of H5N1, a completely different type of influenza, a dog in Thailand caught the disease by eating an infected duck. (H5N1 is also known as avian flu.)

Canine influenza background
The H3N8 influenza virus was discovered in 2004 after an outbreak on a racetrack in Florida. The virus is believed to have spread from horses to Greyhounds, since both animals competed on the same tracks. This was the first time in history that influenza A could be scientifically proven as causing influenza in dogs. Further investigations of serum taken from racing Greyhounds between 1984 and 2004 did however show dogs infected with canine influenza virus (CIV) as far back as 1999.

By analysing the genome of the canine influenza virus, scientists have confirmed that H3N8 was transmitted from horses to dogs and then adapted to dogs through point mutations in the genes.

Since influenza A has not occurred in dogs until the end of the 20th century (at least as far as we know), dogs have no natural immunity. When the virus enters a group of dogs, e.g. on a dog show, it normally spreads very quickly and a lot of dogs become infected. Thankfully, very few of the infected dogs die – especially not if they receive treatment for the secondary infections that can develop.

The influenza A virus is a enveloped negative sense single-stranded RNA virus. It is roughly 80-120 nanometres wide and 200-300 nm long. There are no known instances where canine influenza has spread from a dog to a human, a cat, or a horse.

Dog flu symptoms
When dogs become infected with canine influenza, roughly 80 percent of them develop noticeable symptoms. The incubation time is 2-5 days. A majority of the dogs develop only mild symptoms, but there are exceptions. Dog influenza can for instance lead to pneumonia (normally accompanied by high fever).

These are the most common symptoms of canine influenza in dogs:
- A cough that lasts for 10-30 days
- Greenish nasal discharge
- Fever

Canine influenza diagnosis
For a definite diagnosis, the vet can take a serum sample from the dog and send it to a laboratory that carries out a PCR test for canine influenza viruses. In many cases, upper respiratory disease in a dog proved to be vaccinated against the major causes of kennel cough will make the vet suspect canine influenza, especially if other dogs in the area has been diagnosed with it.

Canine influenza prevention
Unfortunately, there is no canine influenza vaccine available. Research indicates that a canarypox-vectored vaccine for equine influenza virus might be useful, but much more studies and tests are necessary.

The viruses behind canine influenza can be easily killed with common disinfectants, e.g. household bleach solutions.

A dog suffering from canine influenza should ideally be separated from other dogs, because it can release viruses for 7-10 days after showing the first symptoms. There are no known instances where a dog has become a persistent carrier of the disease.

Canine influenza treatment
There is no cure for canine influenza and the vet can only focus in alleviating the symptoms. If secondary bacterial infections set in, antibiotics can become necessary. If the dog develops pneumonia, the survival chance can be lower than 50% if you do not take it to a vet and provide it with correct care. Autopsies performed on dogs that died after having contracted canine influenza showed that they had developed severe hemorrhagic pneumonia and/or vasculitis





Canine influenza


Canine influenza, commonly referred to as dog flue, is caused by varieties if the Influenza A virus capable of creating influenza in dogs and other canines. Among these varieties, the qquine influenze virus H3N8 is generally considered to be the most important one.

During an outbreak of H5N1, a completely different type of influenza, a dog in Thailand caught the disease by eating an infected duck. (H5N1 is also known as avian flu.)

Canine influenza background
The H3N8 influenza virus was discovered in 2004 after an outbreak on a racetrack in Florida. The virus is believed to have spread from horses to Greyhounds, since both animals competed on the same tracks. This was the first time in history that influenza A could be scientifically proven as causing influenza in dogs. Further investigations of serum taken from racing Greyhounds between 1984 and 2004 did however show dogs infected with canine influenza virus (CIV) as far back as 1999.

By analysing the genome of the canine influenza virus, scientists have confirmed that H3N8 was transmitted from horses to dogs and then adapted to dogs through point mutations in the genes.

Since influenza A has not occurred in dogs until the end of the 20th century (at least as far as we know), dogs have no natural immunity. When the virus enters a group of dogs, e.g. on a dog show, it normally spreads very quickly and a lot of dogs become infected. Thankfully, very few of the infected dogs die – especially not if they receive treatment for the secondary infections that can develop.

The influenza A virus is a enveloped negative sense single-stranded RNA virus. It is roughly 80-120 nanometres wide and 200-300 nm long. There are no known instances where canine influenza has spread from a dog to a human, a cat, or a horse.

Dog flu symptoms
When dogs become infected with canine influenza, roughly 80 percent of them develop noticeable symptoms. The incubation time is 2-5 days. A majority of the dogs develop only mild symptoms, but there are exceptions. Dog influenza can for instance lead to pneumonia (normally accompanied by high fever).

These are the most common symptoms of canine influenza in dogs:
- A cough that lasts for 10-30 days
- Greenish nasal discharge
- Fever

Canine influenza diagnosis
For a definite diagnosis, the vet can take a serum sample from the dog and send it to a laboratory that carries out a PCR test for canine influenza viruses. In many cases, upper respiratory disease in a dog proved to be vaccinated against the major causes of kennel cough will make the vet suspect canine influenza, especially if other dogs in the area has been diagnosed with it.

Canine influenza prevention
Unfortunately, there is no canine influenza vaccine available. Research indicates that a canarypox-vectored vaccine for equine influenza virus might be useful, but much more studies and tests are necessary.

The viruses behind canine influenza can be easily killed with common disinfectants, e.g. household bleach solutions.

A dog suffering from canine influenza should ideally be separated from other dogs, because it can release viruses for 7-10 days after showing the first symptoms. There are no known instances where a dog has become a persistent carrier of the disease.

Canine influenza treatment
There is no cure for canine influenza and the vet can only focus in alleviating the symptoms. If secondary bacterial infections set in, antibiotics can become necessary. If the dog develops pneumonia, the survival chance can be lower than 50% if you do not take it to a vet and provide it with correct care. Autopsies performed on dogs that died after having contracted canine influenza showed that they had developed severe hemorrhagic pneumonia and/or vasculitis





Canine minute virus


Canine minute virus is a virus that infects dogs and can cause respiratory and gastrointestinal problems, especially in young puppies. This infectious disease is caused by a virus belonging to the family Parvoviridae. This family is home to some of the smallest known viruses in the world, and these viruses are also known to be extremely environmental resistant and capable of surviving for long periods of time. They can affect both vertebrates and insects. The parvovirus were discovered and scientifically described during the 1960s. Scientists investigating the protein structure and DNA of the Canine minute virus have found it to be very similar to the bovine parvovirus which infects cattle. Another fairly close relative is the human bocavirus which causes respiratory problems in humans. When the first Canine minute virus was discovered in 1967, it lived in military dogs in Germany. Initially, the scientists didn’t believe that the virus actually caused disease in the dogs.

Canine minute virus transmission
Adult dogs and puppies are infected orally. If a pregnant dog is infected, the virus will spread through the placenta and infect the foetuses. Experiments have shown that if the dam (pregnant dog) is infected at 25-30 days of gestation, the virus can cause a miscarriage. If the dam instead infected at 30-35 days of gestation, miscarriage is less common and the puppies can instead be born with birth defects, such as anasarca and myocarditis. The Canine minute virus can also cause lesions in the lungs and small intestine in foetuses.

Canine minute virus symptoms
Puppies aged 1-3 weeks normally develop the most severe Canine minute virus symptoms, which are difficulty breathing, loss of appetite and severe diarrhoea. In severe cases, the puppy will die





Canine minute virus


Canine minute virus is a virus that infects dogs and can cause respiratory and gastrointestinal problems, especially in young puppies. This infectious disease is caused by a virus belonging to the family Parvoviridae. This family is home to some of the smallest known viruses in the world, and these viruses are also known to be extremely environmental resistant and capable of surviving for long periods of time. They can affect both vertebrates and insects. The parvovirus were discovered and scientifically described during the 1960s. Scientists investigating the protein structure and DNA of the Canine minute virus have found it to be very similar to the bovine parvovirus which infects cattle. Another fairly close relative is the human bocavirus which causes respiratory problems in humans. When the first Canine minute virus was discovered in 1967, it lived in military dogs in Germany. Initially, the scientists didn’t believe that the virus actually caused disease in the dogs.

Canine minute virus transmission
Adult dogs and puppies are infected orally. If a pregnant dog is infected, the virus will spread through the placenta and infect the foetuses. Experiments have shown that if the dam (pregnant dog) is infected at 25-30 days of gestation, the virus can cause a miscarriage. If the dam instead infected at 30-35 days of gestation, miscarriage is less common and the puppies can instead be born with birth defects, such as anasarca and myocarditis. The Canine minute virus can also cause lesions in the lungs and small intestine in foetuses.

Canine minute virus symptoms
Puppies aged 1-3 weeks normally develop the most severe Canine minute virus symptoms, which are difficulty breathing, loss of appetite and severe diarrhoea. In severe cases, the puppy will die





Infectious canine hepatitis


Infectious canine hepatitis, sometimes referred to as dog hepatitis, is caused by canine adenovirus type-1 (CAV-1) and leads to an acute liver infection. Dogs are not the only ones susceptible to this disease; it can infect wolves, coyotes and even bears. When foxes are exposed to the virus the normally develop encephalitis instead of liver infection.

Infectious canine hepatitis transmission
Infectious canine hepatitis is spread via urine, faeces, saliva, blood and nasal discharge from infected dogs. It can actually be released in the urine of a dog up to 12 months after the dog has recovered from the infection. A dog becomes infected through nose or mouth, and the virus will travel to the tonsils where it multiplies. After a while, there virus colony will be large enough to infect kidneys and liver of the dog. The incubation period for infectious canine hepatitis is 4-7 days.

Infectious canine hepatitis symptoms
Common symptoms of infectious canine hepatitis are depression, loss of appetite, fever, coughing, corneal oedema and a tender abdomen. When the liver gets infected, it can manifest in the form of jaundice, vomiting and hepatic encephalopathy. If the disease progresses further, it can lead to severe bleeding disorders which can be noticed in the form of hematomas in the mouth. Most dogs will survive infectious canine hepatitis, but liver disease as well as bleeding disorders can naturally have a fatal outcome and you should always take your dog to the vet if you suspect infectious canine hepatitis. Even if the dog recovers, it may retain chronic corneal oedema and kidney lesions.

Infectious canine hepatitis diagnosis
In addition to evaluating the symptoms, the vet can check the blood of your dog for signs of infectious canine hepatitis. A rising antibody titer to CAV-1 is often seen in infected dogs.

Sometimes it can be hard to distinguish infectious canine hepatitis from canine parvovirus, especially in young, unvaccinated dogs where both diseases can cause bloody diarrhoea and a low white blood cell count.

Infectious canine hepatitis vaccination and prevention
You can prevent infectious canine hepatitis in your dog by vaccinating it. Most modern combination vaccines will today contain a modified version of the adenovirus type-2 virus, and this virus is so similar to CAV-1 that the dog will become immune to both viruses. Dogs are seldom vaccinated against only CAV-1, since the CAV-1 vaccine is more prone to causing side effects. The effect of the adenovirus type-2 virus vaccine is not life long, but it will normally last for at least four years.

If you want to kill the CAV-1 outside its host, you can use quaternary ammonium compounds. You can also have clothing and bedding steam cleaned. If you do not disinfect, the virus can stay alive for several months.

Infectious canine hepatitis treatment
There is no cure for infectious canine hepatitis, but most dogs will recover on their own if otherwise healthy and well cared for. The vet can alleviate the symptoms and watch for signs of secondary disease. Seeking veterinary attention is always recommended.


Kennel cough


Kennel cough is an infectious respiratory disease. It is called Kennel cough since it usually appears in environments where a lot of dogs are confined close together, such as kennels. There is no single culprit behind Kennel cough; it can be caused by one of several viruses or by a bacterium named Bordetella bronchiseptica. Sometimes the reason behind Kennel cough is the well known canine distemper virus, the canine respiratory corona virus, the canine parainfluenza virus, or the canine adenovirus. It is therefore important to get a proper diagnosis if your dog develops a cough. The scientific name for Kennel cough is Tracheobronchitis, since it causes inflammation of the upper respiratory system.

Kennel cough is very similar to the disease that we refer to as a “cold” when it occurs in humans, and just like the cold is it usually not dangerous for otherwise healthy individuals. It can however be dangerous for weak dogs and it can develop into pneumonia.

Kennel cough symptoms
Symptoms of Kennel cough normally manifests 3-5 days after exposure. Kennel cough is an inflammation of the upper respiratory system of the dog and the symptoms can last for 10-20 days. Sometimes the affected dog will develop secondary infections, primarily pneumonia.

Symptoms of Kennel cough:
Coughing, often harsh, dry and hacking
Retching/gagging
Snorting
Sneezing
Fever (although many dogs never develops a fever)

Snorting and gagging is especially common after exercise and excitement, or when you gently press the trachea of your dog.

Kennel cough transmission
Both viruses and bacteria capable of causing Kennel cough can spread through the air when infected dogs cough and sneeze. Kennel cough can also spread via contaminated surfaces such as crates and toys, and through direct contact.

Kennel cough prevention and vaccination
Since a wide range of virus and bacteria can cause Kennel cough, it is impossible to give your dog a single shot against it. You can however decrease the risk of your dog getting Kennel cough by vaccinating it against canine distemper, canine adenovirus, canine parainfluenza and Bordetella bronchiseptica. A lot of kennels and dog day care centres work against Kennel cough by requiring all dogs to be vaccinated against these diseases before taking them in as boarders.

Keeping surfaces disinfected is one way of decreasing the risk of Kennel cough. This is especially important in facilities where a lot of dogs gather, such as kennels, day care centres for dogs, dog shows, grooming parlours, and similar.

A lot of things can make your dog more susceptible to Kennel cough than normally and by avoiding them, you decrease the risk of Kennel cough.

Prolonged exposure to cold.
Poor ventilation.
Exposure to cigarette smoke.
Exposure to heavy dust.
Shipping stress.
Crowding stress.
Kennel cough treatment
In most cases, Kennel cough will go away on its own in an otherwise healthy and well cared for dog. If the vet knows for sure that the cough is caused by a bacterium antibiotics can be delivered, but they will be useless against all types of virus. If the cough is unproductive, i.e. when nothing is being coughed up, cough suppressants can be used to milder the symptoms.

Kennel cough can open the field for secondary bacterial infections, including pneumonia, and in such cases antibiotics are strongly recommended. Young puppies that have been shipped recently, especially so called pet store puppies, are extra prone to having their Kennel cough developing into pneumonia.

When Kennel cough is caused by a dangerous virus, e.g. canine distemper virus, the scenario is much more severe and extensive veterinary treatment combined with quarantining is necessary



Pseudorabies in dogs


Pseudorabies, also known as Aujeszky's disease, is a virus disease primarily found in swine. It can however spread to many other mammals, including dogs where it can cause symptoms similar to those caused by true rabies. The Pseudorabies virus (PRV) is endemic in most parts of the world and was first described in 1813. The scientific name for the virus is porcine herpesvirus 1. When the disease manifest in cattle it is called “Mad Itch”.

Pseudorabies background
The first described instances of what was probably Pseudorabies dates back to 1813 when it infected cattles in the United States. The cattle became extremely itchy and the disease was referred to as Mad Itch. The virus was isolated from a dog, a cat and an ox in 1913 by a Hungarian veterinarian named Aládar Aujeszky. Aujeszky managed to show that the same virus was found in all three animals, and that is also cause the same disease in rabbits and swine. Due to his efforts, Pseudorabies is also known as Aujeszky's disease.

Pseudorabies transmission
Infected swines will extract the virus in saliva and nasal secretions and the virus will spread to other animals via oral or nasal contact. It is also possible for PRV to spread through tiny drops that travel through the air or by surviving on various surfaces, e.g. transport cages used by many different animals without being disinfected. If the air is humid, the Pseudorabies virus can stay alive for up to seven hours and drift several kilometres with the wind. This virus is also known to survive for seven hours in water and up to two days in soil, grass and faeces. It can live up to three days in food and four days in straw bedding.

Another problem with this virus is that is has so many secondary hosts. A secondary host is a host that becomes infected directly from swine, by eating infected uncooked pork, or by having contact with other secondary hosts. Dogs, cats, horses, cattle, and rats can all function as secondary hosts. There are no reports of humans becoming secondary hosts.

Pseudorabies diagnosis and prevention
Pseudorabies can be diagnosed through an Enzyme-Linked ImmunoSorbent Assay Test (an ELSA test). In order to prevent the disease, a vaccine can be administered, but vaccinating dogs is not very common. In both the United States and the United Kingdom, extensive eradication programs have been launched to combat Pseudorabies. By 2004, the commercial swine population in the United States could be declared free of the disease, but Pseudorabies is still occurring in feral pigs.

Pseudorabies symptoms in dogs and other animals
Pseudorabies is very dangerous for the secondary hosts, including dogs, and they typically die within 2-3 days. When a dog becomes infected the first symptom is usually intense itching and howling, which is then followed by neurological malfunctions (including jaw and pharyngeal paralysis) and eventually death. When a cat is infected it will normally die before even having time to develop any symptoms.

Swine are much more resilient towards Pseudorabies than the secondary hosts. Piglets less than one month of age usually dies if they become infected, but if the pig is 1-6 months of age the risk of dying is less than 10 percent. In swine, Pseudorabies manifest in the form of sneezes, coughs, depressions, exess salivation, constipation, ataxia, seizures and circling. It can also lead to miscarriages



Rabies in dogs


Rabies is a viral disease that causes acute inflammation of the brain (encephalitis). It can affect any mammal, dogs and humans included. Rabies is not only dangerous for dogs, it is usually deadly for humans as well, and only a very limited number of infected humans have survived the infection, most of them with permanent brain damage as a result. If you have been bitten by an infected animal, you can however prevent the disease from breaking out by seeking medical attention and receiving a full rabies vaccination. The vaccination must naturally be administered soon after the bite to be effective. Since rabies is dangerous for humans, rabies in dogs is considered a health hazard and most countries have rules requiring infected dogs to be put to sleep.

In many parts of the world, all dogs have to be vaccinated against rabies to prevent them from spreading the disease to humans and animals. There are several rabies-free jurisdictions in the world, and these countries and regions normally have really strict regulations when it comes to taking dogs and other animals across their borders. In January 2006, Australia, Fiji, Guam, Hawaii, Iceland, Ireland, Japan, New Zealand, Norway, Sweden, Taiwan/ROC, and the United Kingdom were considered rabies free.

Rabies in dogs is often the result of the dog being bitten by another dog, but a long row of wild animals are also known to transmit the disease. Bats, racoons, foxes, wolves, monkeys, skunks and weasels can for instance have rabies. Cats and domestic farm animals can also have and transmit rabies. Rabies is uncommon in rodents, rabbits and squirrels. Bites are not necessary to transmit rabies; the virus can also be transmitted via an aerosol through mucous membranes.

When a dog develops dog rabies, the virus is normally present in its saliva and in the nerves. Rabies in dogs can make them highly aggressive and cause them to attack without any apparent reason. The dog's brain will deteriorate and the dog will behave more and more bizarre and out of character.

If your dog gets bitten by another dog – especially if the dog is unknown – you should contact a veterinarian immediately. If your dog receives rabies vaccination in time, this can halt the progress of the disease. The same is naturally true if your dog is bitten by any other mammals that might be carrying the rabies virus. The veterinarian will treat your dog immediately, without waiting for any signs of illness.

If you suspect that a dog or any other animal is infected with rabies, you should contact you local authorities, such as the police. Do not try to catch the animal yourself, since you might be bitten.

Even if you believe that your dog will never catch rabies, you should still have it vaccinated. If your dog starts behaving erratically or bite another animal or human and a veterinarian suspect that your dog might be infected with rabies, most countries have laws that stipulate that the dog should be apprehended, put to sleep and subjected to an autopsy. If you have vaccinated your dog against rabies, rabies can be out ruled as the cause of your dog's behaviour and you can avoid this from happening. In some countries, it will however be enough to confine the dog for 10 days, as long as it is not showing any clear neurological signs. If your dog has been bitten by a wild animal, you may however be forced to confine it for 6 months since it can take several months for the symptoms to appear

Bacterial infections in dogs


Bacteria is a natural part of the organism blend living inside dogs and on their skin, just like bacteria live inside humans and on our skin. Bacteria can be highly useful and for instance help us with digestion, but bacteria can also cause a wide range of disease in dogs and people alike. In some situations, even normally harmless bacteria can cause serious health problems in dogs, e.g. when an antibiotics treatment kills off the normal bacterial flora in the body of a dog, thereby allowing antibiotic resistant bacteria to grow without any competition. A few examples of dog diseases caused by bacteria are Lyme disease, Rocky Mountain spotted fever, Brucellosis, Leptospirosis, Ehrlichiosis and Clostridium.

What are bacteria?
Bacteria (the singular form is bacterium) are unicellular micro-organism that come in many different shapes, including spirals, spheres and rods. Bacteria are normally a few micrometers long; much bigger than viruses. Bacteria is found all over the world, even in the most adverse environments such as acidic hot springs and regions contaminated by radioactive waste.

Bacteria and antibiotics for dogs
Bacterial infections in dogs can often be successfully combated with the help of antibiotics, but it is important to contact a veterinarian to obtain a proper diagnosis and get the right type of antibiotics. Certain antibiotics are more suitable than others for certain diseases, and the choice of antibiotics will also be determined by the overall health status of your dog. A pregnant bitch must for instance avoid certain types of antibiotics, while adult dogs might be suitable candidates for certain types of antibiotics that are not given to young dogs due to the risk of problems 5 or 10 years down the road. The dosage must also be adjusted in accordance to weight and age of your dog.

What are antibiotics?
Antibiotics are chemical compounds capable of abolishing or at least inhibiting the growth of micro-organisms. Originally, the term antibiotics was used for all agents with biological activity against living organisms, but today the term is normally reserved for substances used to control the growth of bacteria, fungi and/or parasites.

The first known antibiotics used by doctors and veterinarians were all isolated from living organisms, including the famous penicillins which are produced by fungi. Before antibiotics were discovered, bacterial disease was often treated with various chemical compounds that also damaged the patient, such as arsenic and strychnine. The new antibiotics were much better at targeting malicious microbes and produced less severe side effects.

Side effects in dogs
When your dog receives antibiotic treatment, you should keep an eye on possible side-effects. The exact side effects will depend on a wide range of factors, including how the antibiotics are administered, which antibiotics that are used, the dosage, and the overall health status of your dog. Common antibiotics side effects experienced by dogs are nausea, diarrhea, fever, and allergic reactions. Antibiotics can also interact with other drugs and supplements and it is important to tell the vet about any drugs and supplements, including natural remedies, that you give your dog.

Bacterial infections in dogs: (click for more info)
Aspergillosis in dogs
Brucellosis in dogs
Clostridium in dogs
Ehrlichiosis in dogs
Leptospirosis in dogs
Rocky Mountain spotted fever in dogs

Aspergillosis in dogs


What is Aspergillosis?
Aspergillosis is a disease caused by fungi from the genus Aspergillus, primarluy Aspergillus fumigatus and Aspergillus terreus. When dogs develop Aspergillosis, the reason is usually the fungus named Aspergillus fumigatus. The infection is normally limited to the nose and common symptoms of Aspergillosis in dogs are a runny nose, sneezing, and nosebleeds. There can also be signs of ulcerations of the nose.

Aspergillus fungi are found all over the world and can attack both birds and mammals. It is found in domestic animals and wild animals alike. Different animals develop different symptoms, and a fungus that causes a runny nose for your dog can cause lung infections in birds and miscarriages and cattle. Generalized Aspergillosis is rare in dogs, but the disease can spread to the intervertebral sites and the kidneys.

Aspergillosis symptoms in dogs
When dogs are infected by Aspergillosis, the disease is usually limited to the nasal and paranasal cavities and this is where you can notice the symptoms. In addition to sneezing, nasal discharge from one or both nostrils, nasal pain and ulceration of the nares, the dog can become lethargic and develop frontal sinus osteomyelitis and epistaxis. Nasal Aspergillosis is chiefly a problem for dog breeds with long, narrow heads, where the disease starts in the posterior region of the ventral maxilloturbinate.

Aspergillosis in dogs can lead to gross lesions, but this will vary a lot from case to case. In some dogs, the mucosa found in the nasal and paranasal cavities will be covered in fungal growth and a layer of gray-black necrotic material (dead tissue). Sometimes the underlying bone can also start to die, which can be seen if the head of the dog is x-rayed.

It is possible for Aspergillosis to spread from the original point of entry to other parts of the dog's, so called disseminated Aspergillosis. For reasons unknown, this is more common in certain breeds, such as German Shephards. When this happens, Aspergillus fumigatus is seldom the culprit, the causative fungi is instead normally Aspergillus terreus or even Aspergillus deflectus. Common symptoms of disseminated Aspergillosis in dogs are loss of appetite, weight loss, weakness, urinary incontinence, fever, hematuria, neurological problems, and generalized lymphadenopathy. Lesions can appear inside the spleen, kidneys and vertebrae, and discospondylitis is common.

Aspergillosis treatment for dogs
As long as the disease is limited to nasal and paranasal parts of the dog, topical treatment is preferred in most situations. Most veterinarians opt for Clotrimazole to begin with. This drug can either be administered as a single infusion through the nares or via the frontal sinuses of the dog. Local infusions normally cure 4 out of 5 dogs with nasal and paranasal Aspergillosis.

When the Clotrimazole is given through the nares, foley catheters are normally used to instill 0.5 g of Clotrimazole in each side of the dog's nasal cavity. The infusion is then left there for 60 minutes, during which the veterinarian will turn the dog around once in a while to increase penetration and make sure that the drug spreads out as much as possible.

Enilconazole is an alternative to Clotrimazole treatment and have a similar success rate. When Enilconazole is used, tubes are implanted surgically into the frontal sinuses of the dog. Enilconazole is then used in the form of instilled bid for 1-2 weeks. The normal dose is 10mg per kilogram body weight.

If local treatment is not enough, anti- Aspergillosis drugs can be given systemically. Examples of drugs that work in such treatments are Itraconazole, Fluconazole and Ketoconazole. Itraconazole and Fluconazole tend to be more effective than Ketoconazole. The standard dose for Itraconazole is 5-10 mg per kg bodyweight given once a day, while the dose for Fluconazole varies from 2.5 to 10 mg/kg and should be divided into several servings per day. If Ketoconazole is used, 5-10 mg/kg bodyweight should be given once a day for 6-8 week


Brucellosis in dogs


Brucellosis is a bacterial disease that can lead to a wide range of problems, including orchitis (testicle inflammation), uveitis (inflammation of the middle layer of the eye), and miscarriage in dogs. Dogs are not the only ones affected by this disease; it infects a lot of domestic animals world wide, including cattle, swine and goats. Humans can also suffer from Brucellosis. In dogs, the disease is caused by a bacterium named Brucella canis, while goats and sheep are infected with Brucella melitensis, pigs with Brucella ovis, and so on.

Brucellosis transmission in dogs
In dogs, sexual transmission is the most common form of Brucellosis transmission. They can however get the disease in other ways as well, e.g. by having contact with foetuses that has been aborted due to Brucellosis.

Brucellosis symptoms in dogs
In dogs, the Brucellosis bacteria normally settle down in the genitals and the lymphatic system, but it is possible for it to spread to the kidneys, eyes and the intervertebral disc as well. When Brucellosis infects the intervertebral disc, the result is discospondylitis.

In dogs, symptoms from the reproductive organs are common. Male dogs can for instance develop scrotal and testicular inflammations, while female dogs can have miscarriages. Fever is uncommon, but the pain associated with Brucellosis can make the dog weak. If the disease spreads to kidneys, eyes or the intervertebral disc symptoms can begin to show from these organs.

Brucellosis prevention
The best way of preventing Brucellosis is to test all dogs prior to breeding. A blood test can show if the dog is infected with Brucellosis. Avoiding “accidental” mating is naturally also important.

You have to be careful when handling dogs infected with Brucellosis, because humans can catch Brucellosis from animals, e.g. by having contact with aborted foetuses, blood or semen. If you only pet and care for your dog in a normal fashion and leave everything that involves blood and semen to the veterinarian your risk of getting Brucellosis is very low. If your immune system is compromised, e.g. due to HIV, cancer or immunosuppressant drugs (common after transplants) you should not care for a dog with Brucellosis.

Brucellosis treatment for dogs
Brucellosis in dogs can be treated with antibiotics, but it is hard to cure and prolonged medication is often required. Antibiotics such as rifampicin, tetracycline, streptomycin and getnamicin are all effective against the Brucella bacteria.

One frequently used method is to use a combination of doxycycline and rifampin during 6 weeks. Another combination is intramuscular injections of streptomycin for two weeks combined with doxycyline pills for 45 days. It can however take several months for the dog to fully recover. Fatal Brucellosis is uncommon, but in a few cases the does disease leads to endocarditis.

The reason why antibiotics have to be administered during several weeks is the fact that the Brucellosis bacteria incubates within the cells of the dog. Using doxycycline only is never a good idea, because doxycycline needs to be combined with other drugs to prevent the Brucellosis from reappearing.






Canine Leptospirosis:

Current Issues on Infection and Vaccination

Leptospirosis, a contagious disease affecting both animals and humans and spread by infection with a bacterial pathogen called Leptospira, may result in chronic liver and kidney disease and fatality in the dog. Over the past 30 years, preventative vaccination against two of the most common Leptospires, L. canicola and L. icterohaemorrhagiae, have nearly eradicated clinical disease associated with these strains among the inoculated population. Though not without potential side effects associated with allergic reactions to inoculant in a small number of dogs, the risks of not vaccinating for Leptospirosis once far outweighed risks of vaccine-reaction. In recent years, however, new outbreaks of Leptospirosis have been reported in the population of vaccinated dogs. Clinical evidence now suggests that these new cases are associated with the once, less-common Leptospires for which current vaccines do not protect against. In light of these findings, the process of vaccinating dogs with the current Leptospirosis vaccines is being seriously questioned.

The following article provides a detailed examination of infectious Leptospirosis in the canine and the recent clinical findings and misconceptions surrounding the controversy of using current vaccines to immunize dogs.



Infectious Leptospirosis

The Leptospira Organism. Leptospires are known as "aquatic spirochetes": they thrive in water and appear long and helical with a characteristic hook on one or both ends. These organisms are divided into two species, Leptospira biflexa and Leptospira interogans, the latter of which is pathogenic in animals and humans. L. interogans is divided into strains, or serovars, based upon the types of antigens (cell-surface markers against which the infected host will make antibodies) on their surface. These cell surface antigens provide little cross-immunity against one serovar and the next; that is, a dog that has developed immunity to one strain by either previous infection or vaccination will not be able to immunologically fend-off an infection of a different, subsequent strain. Despite this, however, these antigens may be cross-reactive in serological testing; that is, diagnostic testing to differentiate one serovar infection from another may lead to false-positive results because some antigens from one strain may have similarities to antigens from another strain.



Serovar prevalence. As recent as the 1980s, L. icterohaemorrhagiae and L. canicola were identified as the most prevalent serovars causing Leptospirosis in the canine. By the 1990s, however, an increased incidence of L. grippotyphosa and L. pomona was observed in conjunction with a resurgence of Leptospirosis disease suggesting a changing trend in the epidemiology of this disease. It is speculated that these changes in serovar prevalence are related to two primary factors that may strongly influence the epizootiology of Leptospira serovars. These factors are: 1) preventative vaccination has all but eradicated clinical disease in the domestic dog and 2) there has been an increased migration of wildlife, for which serovar infections with L. grippotyphosa and L. pomona are most prevalent, into suburban areas.



Modes of Disease Transmission. Leptospira thrive in spring and autumn when wet soil conditions and moderate temperatures support their otherwise poor environmental survivability. Infection by contact with infected urine or ingestion of urine-contaminated water is the most common means of transmission of the disease. Less common modes of infection include transmittance of the organisms during breeding, gestation, or through the membranes of the eyes, abrasions or bite wounds, or ingestion of the flesh from infected animals such as rats, raccoons, skunks or opossums. A serovar infects the dog as a maintenance host, using the dog to carry out most, if not all of the organism's life cycle. Under these conditions, the kidneys of the infected dog become the "breeding" grounds for the serovar, some of which will be shed in the urine where they may gain access to other dogs and continue the infectious cycle.



Symptoms of disease. During the first 4-12 days following infection with Leptospira, the dog may experience sudden symptoms of fever (103-105oF), depression, vomiting, loss of appetite, conjunctivitis, and generalized pain. Within 2 days of the onset of these primary symptoms, body temperature may drop suddenly and there may be a noticeable increase in thirst. A definite change in the color of the dog's urine and/or jaundice (icterus) is often noticed and may be the only indication of disease. Color intensity of the urine may vary from lemon to deep orange. Additionally, frequent urination and subsequent dehydration (uremia) are consistent with invasion of the kidney tubule cells by the Leptospira organism and usually present within a few days of the primary symptoms. In advanced cases of infection, profound depression, difficulty breathing, muscular tremors, bloody vomitus and feces are often observed as the infection progresses to include the liver, gastrointestinal system and other organs. Course and severity of the disease is often dependent upon the serovar responsible for the infection. Serovars associated with liver infection and symptoms of urine discoloration and/or jaundice (icterus), elevation of liver enzymes, and gastrointestinal symptoms include L. icterohaemorrhagiae and grippotyphosa. The serovar grippotyphosa is also associated with symptoms of renal failure as is the serovar pomona.



Diagnosis. Given the nonspecific symptoms often associated with Leptospira infection, definitive diagnosis must be based on the combination of symptoms and results from laboratory and serologic tests. Despite this, however, Leptospirosis should be among the primary suspected causes of illness in dogs presenting with sudden-onset kidney dysfunction. Laboratory testing of blood chemistry and urine provide evidence of abnormalities of components of the blood, elevation in liver enzymes, electrolyte imbalances, and active urinary sediments all consistent with vascular, liver, and kidney disease associated with Leptospira infection. The most commonly used serologic test includes the microscopic agglutination test (MAT), which titrates reactivity of antibodies in the patient's serum with live leptospires. Limitations to MAT include false-negative results early in the course of the disease, reduced positive response in vaccinated dogs that may be harboring chronic infection, and cross-reactivity excluding the ability to distinguish between serovars. Other serological tests including the enzyme-linked immunosorbent assay (ELISA) and microcapsular agglutination test (MCAT) are more specific, reducing false-positives associated with vaccinal responses and providing earlier detection by monitoring immunoglobulins specific for immune response to infection (IgM), respectively.



Treatment. Antibiotic therapy in the early course of Leptospirosis infection is efficient in shortening duration of the disease, reducing the time period for risks of contagion, and decreasing the severity of liver and kidney damage. In advanced cases, supportive therapy to compensate for abnormal blood, kidney and liver function may be required. Therapy to restore urine production, kidney filtration and blood flow are essential to reversing kidney failure. In cases of severe liver disease, a decrease in clotting factors in the blood may lead to bleeding disorders requiring treatment by transfusion. Since Leptospirosis poses a risk of contagion to other animals and to humans, special precautions must be taken to prevent transmission of Leptospira from the dog to other animals and human companions or caretakers. All blood, urine, and tissues from a dog suspected or determined to have Leptospirosis must be handled as biologically hazardous waste. Infected dogs should be quarantined and areas of contamination should be washed and disinfected with an iodine-based solution. It is important to note that even after treatment and control of the active disease state, dogs continue to shed serovar in their urine and therefore, may pose an infectious risk to other animals and to humans up to 3 months following infection.



Prognosis. Fatalities as a direct result of Leptospirosis do not usually exceed 10% and usually occur 5-10 days after initial onset of the disease. Death arising from secondary complications associated with progressive kidney and liver damage are common but may not occur for long periods following the initial disease.



Prevention. Commercial vaccines are available and protect against clinical disease associated with the L. icterohaemorrhagiae and L. canicola serovars. Inoculation does not, however, prevent infection and development of a carrier state whereby the dog will be clinically asymptomatic for disease yet provide a source of contagion through the shedding of serovars in its urine. Additionally, vaccinating against these specific serovars does not afford protection against other serovars.



Current Issues Relating to Leptospirosis and Vaccination

Annual Revaccination and Leptospirosis

Current concerns in canine immunology have addressed issues related to overuse of vaccines in dogs and cats. General consensus among specialists in the field is that yearly vaccination against viral infections associated with canine distemper virus, canine parvovirus and canine adenovirus are generally unnecessary since active immunity induced by these vaccines provide at least several years of protection. This consensus, however, does not apply and should not be generalized to bacterin vaccines, which immunize against diseases associated with bacterial organisms. In fact, clinical evidence suggests that bacterin-derived vaccines including those which protect against Bordetella bronchiseptica (kennel cough), Leptospira (Leptospirosis), and Borrelia burgdoferi (Lyme disease) probably don't even provide protective immunity for 12 months suggesting that more frequent vaccination for these diseases are required. It is perhaps the common use of combination (all-in-one) vaccines containing bacterins, which immunize against bacterial infections such as Leptospirosis and/or kennel cough in addition to common viral infections, that gave rise to the practice of frequent vaccine administration. Indeed the incorrect generalization of long-term immunity, associated with vaccination against viral immunogens, to bacterin-based vaccines may lead to a decrease in annual vaccination for bacterial-based diseases and subsequently give rise to a resurgence of outbreaks of bacterial disease in the coming years. In light of this, annual re-boostering against bacterial diseases should continue despite discontinuation of yearly vaccination against viral diseases.



The Current Leptospirosis Vaccine

Recent serological studies on wildlife and domestic dogs suggests that L. grippotyphosa and L. pomona have replaced L. icterohaemorrhagiae and L. canicola as the prevalent serovars responsible for Leptospirosis in the United States today. As such, current commercial vaccines, which protect against the formerly prevalent serovars, would not be effective at providing immunity against Leptospirosis caused by L. grippotyphosa and L. pomona. For this reason, there has been some conjecture that current commercial vaccines should be considered obsolete for protecting against Leptospirosis. There are several factors that should be considered prior to drawing this conclusion. First, Leptospirosis vaccines, as mentioned above, protect against clinical disease but do not prevent subclinical infection to a "carrier" state. That is, a dog that is annually vaccinated may harbor infectious organisms of L. icterohaemorrhagiae or L. canicola which will pose a risk of contagion to dogs that are not vaccinated or in which vaccination for these serovars has been discontinued. Without serological testing, low clinical incidence of these formerly prevalent serovars may be a result of the currently large population of vaccinated dogs. If this is the case, discontinuing administration of the current Leptospirosis vaccine may result in a resurgence of clinical disease. Furthermore, it is important to note that samples from these studies are not necessarily representative of all regions of the US.

When all the facts are considered, these findings do not necessarily suggest that L. icterohaemorrhagiae and L. canicola no longer pose a threat to dogs. Rather, this information should be taken into consideration when determining potential risk of infection in dogs that may be candidates for side effects associated with vaccine-reaction. Leptospirosis-containing vaccines are associated with a higher risk for side effects, particularly, anaphylactic reactions (see Canine Anaphylaxis). Taken together, benefits of vaccinating dogs, who live in areas where icterohaemorrhagiae and canicola incidence is low and who may have a higher predisposition for vaccine side effects with current Leptospirosis inoculants (see Vaccines, Infectious Diseases and the Canine Immune System), may not outweigh risks of vaccine reaction.



New Leptospirosis Vaccine Immunizes Against L. grippotyphosa and L. pomona

Fort Dodge now offers the Duramune Leptospirosis vaccine that immunizes against L. grippotyphosa and L. pomona serovars as well as L. icterohaemorrhagiae and L. canicola . This vaccine has been formulated through the new subunit technology that uses only the antigen component of the organism (that will produce an immune response) instead of the entire organism. As such, subunit vaccines greatly reduce vaccine side-effects that occur with higher incidence with bacterin-based vaccines while providing durable protection from the diseas

coccidia in dogs

eThere are many different species of coccidia but for dogs and cats, the
most common infections are with coccidia of the genus Isospora (pictured here).
The information presented here pertains to Isospora species




WHAT ON EARTH ARE COCCIDIA?

Coccidia are single celled organisms that infect the intestine. They are microscopic parasites detectable on routine fecal tests in the same way that worms are, but coccidia are not worms and are not susceptible to deworming medications. They are also not visible to the naked eye. Coccidia infection causes a watery diarrhea that is sometimes bloody and can be a life-threatening problem to an especially young or small pet.

WHERE DO COCCIDIA COME FROM?

Oocysts (pronounced o'o-sists), like those shown above, are passed in stool. In the outside world, the oocysts begin to mature or sporulate. After they have adequately matured, they become infective to any host (dog or cat) that accidentally swallows them.

To be more precise, coccidia come from fecal-contaminated ground. They are swallowed when a pet grooms/licks the dirt off itself. In some cases, sporulated oocysts are swallowed by mice and the host is infected when it eats the mouse. Coccidia infection is especially common in young animals housed in groups (in shelters, rescue areas, kennels, etc.) This is a common parasite and is not necessarily a sign of poor husbandry.

WHAT HAPPENS INSIDE THE HOST?

The sporulated oocyst breaks open and releases eight sporozoites. These sporozoites each finds an intestinal cell and begins to reproduce inside it. Ultimately, the cell is so full of what are at this stage called merozoites that it bursts, releasing the merozoites that seek out their own intestinal cells and the process begins again. It is important to note how thousands of intestinal cells can become infected and destroyed as a result of accidentally swallowing a single oocyst.

As the intestinal cells are destroyed in larger and larger numbers, intestinal function is disrupted and a bloody, watery diarrhea results. The fluid loss can be dangerously dehydrating to a young or small pet.

HOW ARE COCCIDIA DETECTED?

A routine fecal test is a good idea for any new puppy or kitten whether there are signs of diarrhea or not as youngsters are commonly parasitized. This sort of test is also a good idea for any patient with diarrhea and is recommended at least once a year for healthy dogs and cats as a screening test. The above photograph shows coccidia oocysts seen under the microscope in a fecal sample. Coccidia are microscopic and a test such as this is necessary to rule them in. It should be noted that small numbers of coccidia can be hard to detect so just because a fecal sample tests negative, this does not mean that the pet is not infected. Sometimes several fecal tests are performed, especially in a young pet with a refractory diarrhea; parasites may not be evident until later in the course of the condition.

HOW IS COCCIDIA TREATED?

The most common medicines used against coccidia are called coccidiostats. They inhibit coccidial reproduction. Once the numbers stop expanding, it is easier for the patient’s immune system to catch up and wipe the infection out. This also means, though, that the time it takes to clear the infection depends on how many coccidia organisms there are to start with and how strong the patient’s immune system is. A typical treatment course lasts about a week or two, but it is important to realize that the medication should be given until the diarrhea resolves plus an extra couple of days. Medication should be given for at least 5 days total. Sometimes courses as long as a month are needed. In dogs and cats, sulfa-based antibiotics are the most commonly used coccidiostats.

The use of sulfa drugs in pregnancy can cause birth defects. Sulfa drug use can also lead to false positive test results for urine glucose.

There is another medication that is worth mentioning and that is Ponazuril, a large animal product. This medication is actually able to curtail a coccidial infection in five doses or less and has been used in thousands of shelter puppies and kittens with no adverse effects. This product would seem to be superior to the usual sulfa drugs, but the problem that keeps it from becoming a mainstream treatment is the fact that it is available only as a paste for horses and must be diluted down to create an appropriate small animal formula. The large volumes of product yielded are not cost effective if only occasional patients are treated for this parasite. Ponazuril is thus most commonly used in kennels, catteries, and animal shelters though one may be pleasantly surprised to find it in stock at one's regular veterinary office.

CAN PEOPLE OR OTHER PETS BECOME INFECTED?

While there are species of coccidia that can infect people (Toxoplasma and Cryptosporidium, for example), the Isospora species of dogs and cats are not infective to people. Other pets may become infected from exposure to infected fecal matter but it is important to note that this is usually an infection of the young (i.e. the immature immune system tends to let the coccidia infection reach large numbers whereas the mature immune system probably will not.) In most cases, the infected new puppy or kitten does not infect the resident adult animal.



Ear problems in dogs

The ears of a dog are sensitive and you need to check them regularly to make sure that everything is alright. This is especially true for dog breeds where selective breeding have led to ears that are very different from the ear configuration that we can se in wolfs and wild dogs. If your dog has long and floppy ears, the warm and moist air that becomes trapped under them can serve as an ideal breeding ground for bacteria. Some dog breeds, such as the popular Cocker spaniel, have very narrow ear canals and are therefore prone to inner ear infections. Check your dog regularly to detect early signs of infection, e.g. redness, foul smell and/or “dirt”.

When you get a puppy and bring it for its first veterinary check up, ask the vet for professional advice about how to clean the ears of your dog. Improper cleaning can actually increase the risk of ear problems. If you use Q-tips or similar to clean out the ears of your dog, you might involuntarily push debris further into the ear where it can cause serious problems. Strong cleaning solutions or overzealous cleaning can irritate and damage the sensitive skin and increase the risk of secondary ear infections. Your veterinarian can tell you more about which type of ear cleaning regiment that is recommended for the dog breed and your particular dog. Some dogs have ears that are virtually carefree and “self-cleaning”, while others need a lot of care to stay healthy.

Ear problems in dogs can be caused by a wide range of factors, including foreign bodies, parasites, micro organisms, tumours, and skin problems such as allergy. Among the parasites, ear mites are among the most common in the ears of dogs and can lead to ear canal inflammation. Ticks and fleas are also found of dog ears, but can of course be found all over the body. Unfortunately, some dog owners assume that virtually all ear problems in dogs are due to ear mites and treat their dogs for ear mites without first obtaining a proper diagnosis and rule out other possible factors. This exposes the dog to unnecessary treatments and can force the dog to wait several weeks before receiving a treatment that will actually cure the problem.

Among the micro organisms capable of causing ear problems for dogs we will naturally find bacteria and viruses, but also fungi. Yeast infections are fairly common in dog ears, especially in breeds with long and floppy ears. A yeast organism named Malassezia pachydermatitis is especially fond of colonising the ear canals of dogs.

If your dog suffers from reoccurring ear problems and sticking to the cleaning routine recommended by your vet does not help, it is time to look for an underlying cause. Your dog might have an allergy that causes persistent scratching, which in turn causes small wounds that can be colonised by opportunistic bacteria, fungi, etcetera. Hypothyroidism is another health problem that can lead to ear trouble, since hypothyroidism can make the skin of the ear thicker and increase the release of exudates inside the ear canal.

Deafness in dogs


Deafness in dogs can be acquired or something that the puppy is born with. Congenital deafness (something the puppy is born with) can be genetic or caused by something that happened during foetal development such as an infection in the mother. Chronic infections and medications can bring on deafness in dogs, and age-related deafness is also very common – just as in dog owners.

Breed-specific deafness prevalence in dogs
Some dog breeds are more prone to congenital deafness than others. A study carried out on over 5000 Dalmatians did for instance show that nearly 22 percent of them were unilaterally deaf, and 8 percent bilaterally deaf. Another example of a dog breed with an elevated risk for deafness is the Bull Terrier. In this breed, white bull terriers are much more prone to deafness compared to coloured Bull Terriers.

Causes of sudden onset of deafness in dogs
When a dog suddenly goes deaf, it can be caused by a wide range of reasons. It should also be noted that the sudden deafness might not be as sudden as your think; dogs are good at compensating for a gradually decreasing hearing capacity and can keep the dog owner in the dark for long periods of time. One day the hearing loss will be so severe that it is no longer possible for the dog to compensate and the dog owner will think that the dog has “suddenly” turned deaf. Another important thing to keep in mind is that even a one sided problem can cause complete deafness, because the dog might have been deaf on one ear since birth without the owner ever noticing.

Ear inflammation
Infections of the middle or inner ear can lead to temporary or permanent deafness. Always consult a veterinarian in order to get the proper treatment for your dog and prevent deafness.

Infections in the middle ear of the dog can produce “crud” that stays there even after the infection has ended, and this material block the sound transmission and make the dog more or less deaf. Eventually, the body will remove this debris from the ear but it can take some time.

Medications
A lot of different drugs can cause deafness by destroying cochlear hair cells. (Such drugs can also make the dog unbalanced and make it walk in circles, tilt, etcetera.) Medications containing aminoglycoside antibiotics are one example of drugs capable of causing deafness. Examples of such antibiotic drugs include gentamicin, neomycin, kanamycin, and tobramycin. Due to this risk, these antibiotics are normally only used is very serious cases where the dog might die without this treatment.

Cleaning solutions containing chlorhexidine can produce deafness, but such cleaning solutions are no longer commonly used.

Noise
A loud noise can cause temporary or long-lasting hearing loss in dogs. In order to reduce the sound transmission into the sensitive inner ear, muscles in the middle ear of the dog will always contract by reflex. Very sudden noises – such as gun fire – are however too fast for the ear to react and the sensitive inner ear can suffer. Repeated exposure to gun fire, fireworks and similar can lead to cumulative hearing loss for the dog.

‏ليست هناك تعليقات:

The Daily Puppy

Fish