What is Canine "Parvo"?
Canine parvovirus (CPV) infection is a relatively new disease that appeared for the first time in dogs in 1978. 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 this disease is very similar to feline panleukopenia (feline distemper) 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 scientifically proven.
Are there different strains of canine parvovirus?
Two slightly different strains of canine parvovirus, named CPV-2a and CPV-2b, arerecognized. They cause the same disease and vaccines give protection against both.A distinct type of parvovirus (CPV-1) has been found in pups with diarrhea and alsoin normal dogs. CPV-1 is not thought to be an important cause of disease.
How does a dog become infected with parvovirus?
The main source of the virus is from the feces of infected dogs. The virus is shedduring infection and for about two weeks. Susceptible dogs become infected byingesting the virus. Subsequently, the virus is carried to the intestine where itinvades 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, alcohol, and many disinfectants. CPV has been recovered fromsurfaces contaminated with dog feces even after three months at roomtemperature. Due to its stability, the virus is easily transmitted via the hair or feetof infected dogs, contaminated shoes, clothes, and other objects or areascontaminated by infected feces. Direct contact between dogs is not required tospread the virus. Dogs that become infected with the virus and show clinical signswill usually become ill within 7 - 10 days of the initial infection.
How does this disease affect the dog?
The clinical signs and symptoms of CPV disease can vary, but generally they include severe vomiting and diarrhea. The diarrhea often has a very strong smell, may contain lots of mucus and may or may not contain blood. Additionally, affected dogs often exhibit a lack of appetite, marked listlessness and 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 and consistent 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 usually the most severely affected, and the most difficult to treat.
How is it diagnosed?
The clinical signs of CPV infection can mimic many other diseases that cause vomiting and diarrhea; consequently, the diagnosis of CPV is often a challenge for the veterinarian. The positive confirmation of CPV infection requires the demonstration of the virus or virus antigen in the stool, or the detection of anti-CPV antibodies in the blood serum. Occasionally, a dog will have parvovirus but test negative for virus in the stool. Fortunately, this is an uncommon occurrence. A tentative diagnosis is often based on the presence of a reduced white blood cell count (leukopenia) and clinical signs. If further confirmation is needed, stool or blood can be submitted to a veterinary laboratory for additional tests. The absence of a leukopenia does not mean that the dog does not have CPV infection. Some dogs that become clinically ill may not have a low white blood cell count.
Can parvo be treated successfully?
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, and destroys some blood cell elements. The intestinal damage results in severe dehydration (water loss), electrolyte (sodium and potassium) imbalances, and infection in the bloodstream (septicemia). When the bacteria that normally live in the intestinal tract are able to get into the blood stream, 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 the problems.
What is the survival rate?
Most dogs with CPV infection recover if aggressive treatment is used and if therapy is begunbefore severe septicemia and dehydration occur. For reasons not fully understood, somebreeds, notably the Rottweiler, Doberman pinscher and English Springer spaniel, have a muchhigher fatality rate than other breeds.
Can it be prevented?
The best method of protecting your dog against CPV infection is proper vaccination. Puppiesreceive a parvo vaccination as part of their multiple-agent vaccine given at 8, 12, and 16weeks of age. In some situations, veterinarians will give the vaccine at two-week intervalswith an additional booster at 18 to 20 weeks of age. After the initial series of vaccinations,all dogs should be given a booster vaccination at one year. Thereafter your veterinarian willdiscuss with you an appropriate schedule of revaccination. Dogs in high exposure situations(i.e., kennels, dog shows, field trials, etc.) may be better protected with a booster every sixmonths. Pregnant females might be boostered with a killed parvo vaccine within two weeksbefore whelping in order to transfer protective antibodies to the puppies. Your veterinarianshould make the final decision about a proper vaccination schedule.
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 is best accomplished by cleaning food bowls, water bowls, and other contaminated items with a solution of 1/2 cup of chlorine bleach in a gallon of water (133 ml in 4 liters of water). It is important that chlorine bleach be used because most disinfectants, even those claiming to be effective against viruses, 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 there is no evidence to indicate that CPV is transmissible to cats or humans.