What is Canine Parvovirus disease?
Canine parvovirus (CPV) infection is a relatively new disease. Because of the
severity of the disease and its rapid spread through the canine population,
CPV has aroused a great deal of public interest. The virus that causes it is
very similar to feline enteritis, and the two diseases are almost identical.
Therefore, it has been speculated that the canine virus is a mutation of the
feline virus. However, that has never been proven.
How does a dog become infected with parvovirus?
The causative agent of CPV disease, as the name infers, is a virus. The main
source of the virus is the feces of infected dogs. The feces of an infected
dog can have a high concentration of viral particles. Susceptible animals become
infected by ingesting the virus. Subsequently, the virus is carried to the intestine
where it invades the intestinal wall and causes inflammation.
Unlike most other viruses, CPV is stable in the environment and is resistant
to the effects of heat, detergents, and alcohol. CPV has been recovered from
dog feces even after three months at room temperature. Due to its stability,
the virus is easily transmitted via the hair or feet of infected dogs, contaminated
shoes, clothes, and other objects. Direct contact between dogs is not required
to spread the virus. Dogs that become infected with the virus and show clinical
signs will usually become ill within 7-10 days of the initial infection.
How does this disease affect the dog?
The clinical manifestations of CPV disease are somewhat variable, but generally
take the form of severe vomiting and diarrhea. The diarrhea may or may not contain
blood. Additionally, affected dogs often exhibit a lack of appetite, depression,
and fever. It is important to note that many dogs may not show every clinical
sign, but vomiting and diarrhea are the most common signs; vomiting usually
begins first. Parvo may affect dogs of all ages, but is most common in dogs
less than one year of age. Young puppies less than five months of age are often
the most severely affected and the most difficult to treat.
How is it diagnosed?
The clinical signs of CPV infection can mimic other diseases causing vomiting
and diarrhea; consequently, the diagnosis of CPV is often a challenge for the
veterinary surgeon . The positive confirmation of CPV infection requires the
demonstration of the virus in the feces or the detection of anti-CPV antibodies
in the blood serum. Occasionally, a dog will have parvovirus but test negative
for virus in the feces Fortunately, this is not a common occurrence. A tentative
diagnosis is often based on the presence of a reduced white blood cell count
(leukopaenia). If further confirmation is needed, feces or blood can be submitted
to a veterinary laboratory for the other tests. The absence of a leukopaenia
does not always mean that the dog cannot have CPV infection. Some dogs that
become clinically ill may not necessarily be leukopaenic.
Can it be treated successfully?
As with any virus disease there is no treatment to kill the virus once it
infects the dog. However, the virus does not directly cause death; rather, it
causes loss of the lining of the intestinal tract. This results in severe dehydration,
electrolyte (sodium and potassium) imbalances, and infection in the bloodstream
(septicemia). It is when the bacteria that normally live in the intestinal tract
are able to get into the blood stream, that it becomes more likely that the
animal will die.
The first step in treatment is to correct dehydration and electrolyte imbalances.
This requires the administration of intravenous fluids containing electrolytes.
Antibiotics and anti-inflammatory drugs are given to prevent or control septicemia.
Antispasmodic drugs are used to inhibit the diarrhea and vomiting that perpetuate
What is the survival rate?
Most dogs with CPV infection recover if aggressive treatment is used and if
therapy is begun before severe septicemia and dehydration occur. For reasons
not fully understood, some breeds, notably the Rottweiler, have a much higher
fatality rate than other breeds.
Can it be prevented?
The best method of protecting your dog against CPV infection is proper vaccination.
Puppies receive a parvo vaccination as part of the vaccines given at 8 and about
12 weeks of age. In some situations, veterinary surgeons will give the vaccine
at two week intervals and an additional booster at 18 to 20 weeks of age. After
the initial series of vaccinations when the dog is a puppy, all dogs should
be boosted at least once a year. Dogs in high exposure situations (i.e. kennels,
dog shows, field trials, etc.) may be better protected with a booster every
six months. Pregnant bitches should be boosted before mating or immediately
after whelping in order to transfer protective antibodies to the puppies. The
final decision about a proper vaccination schedule should be made by your veterinary
Is there a way to kill the virus in the environment?
The stability of the CPV in the environment makes it important to properly
disinfect contaminated areas. This can be accomplished by cleaning food bowls,
water bowls, and other contaminated items with a solution of one cup of chlorine
bleach in a gallon of water (250 ml in 5 liters of water). It is important that
chlorine bleach be used because most "viricidal" disinfectants will not kill
the canine parvovirus.
Does parvovirus pose a health risk for me? How about for my cats?
It is important to note that at the present time, there is no evidence to
indicate that CPV is transmissible to cats or humans.
to Canine Information Index