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One of the most contagious diseases within the canine population is caused by the Canine Parvovirus. The virus has a special affinity for attacking rapidly reproducing cells, such as those which make up the gastrointestinal tract's lining. It is transmitted by oral contact with infected feces. The disease is in the stools of acutely infected dogs for up to several weeks following infection. Parvo can be carried on the dog's hair, feet, as well as on contaminated crates, shoes or other objects. Dogs of any age can be affected by Parvo, but most cases occur in puppies 6 to 20 weeks of age. Dobermans, Pinchers, and Rottwiellers tend to acquire the infection more easily and experience more severe symptoms, but all dogs are susceptible to the infection. The incubation period of the Parvovirus averages from 4 to 5 days. During this early stage of the illness, the infected dog will experience depression, vomiting, and diarrhea. Some dogs may have a fever as high as 106 degrees while others may have no fever at all. Puppies with severe abdominal pain will exhibit a "tucked up" abdomen. Diarrhea is usually profuse and contains mucous and/or blood. They will become dehydrated very quickly. Parvovirus used to affect the heart muscle in newborn puppies used to be very common, but now is rare because veterinarian encourage breeders to provide vaccinations to their female dogs 2 to 4 weeks prior to breeding them. Doing this boosts the maternal antibody levels and provides better protection for the puppies. If your puppy experiences sudden diarrhea and vomiting, Parvo should always be suspected and needs to be seen by your veterinarian in order to do the necessary tests to diagnose the infection. If possible, get a fresh stool sample to take the vet for their examination of it. Be careful not to spread the virus around and further contaminate the area and yourself. Wash your hands thoroughly with antibacterial soap if possible. The vet will also need to take a blood sample from your pet. Treatment: Vaccines are highly effective, and should be given in a series of up to three injections due to the interference that maternal antibodies can cause in pups that are under 4 months. Puppies should not be exposed to other dogs or the feces of other dogs until the vaccine series is complete. Prevention: As with all infectious disease, minimizing exposure from infected animals is the most effective means of prevention. Since infected dogs shed large amounts of virus in their stool, contamination is always a possibility. Using a bleach solution is an effective means of disinfecting. Since this disease occurs mostly in puppies, worms (internal parasites) and poor nutrition add susceptibility. The canine parvovirus is especially hardy in the environment. NO ENVIRONMENT should be considered free from this virus unless it is regularly disinfected. This includes kennels, dog parks, or any other place where infected dogs may have been. As fun as it would be to have your puppy play with other puppies and dogs in a dog park, it would be a terrible thing to do before the puppy has been fully vaccinated for Parvovirus. The survival rate of a puppy infect with parvovirus is 50 - 50. During the time he/she is infected they experience a great deal of pain If you had a dog die of parvo, we recommend thorough cleaning with diluted bleach and waiting 1-2 months before introducing a new dog to the area. Pups that have recovered from parvo do not get the disease later in life. Here are a few facts about Parvovirus that you might not know about how long it takes to lose its infectiousness:
Despite the
introduction of new cleaners with all sorts of claims, Parvovirus
remains virtually impossible to completely remove from an environment.
The goal of decontamination is to reduce the number of viral particles
to an acceptable level. Disinfection
becomes problematic for non-bleachable surfaces such as carpet or lawn.
Outdoors, if good drainage is available, thorough watering down of the
area may dilute any virus present. Since carpet is indoors, it may be
best to simply wait a good month or so for the virus to die off before
allowing any puppies access to the area. |
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This was an excerpt from the book, "Dog Owner's Home Veterinary Handbook" 3rd Edition by James M. Giffin MD & Liisa D. Carlson, DVM. |
Originally appeared as Ask the Vet by Dr. Shawn Ashley in Pug Talk Magazine (Jan/Feb/92)
In 1978 an epidemic swept the United States in which puppies were dying acutely of severe vomiting, profuse diarrhea, marked dehydration, and circulatory shock. A minute DNA virus resembling the feline panleukopenia (parvo) virus was isolated. Parvovirus-I was isolated from both domestic an wild dogs, wolves, and coyotes. The virus was found highly contagious, being transmitted primarily by the fecal to oral route and fomite contamination. A vaccine was soon derived.
In the late 1980's what was thought to be a different parvovirus was isolated from dogs which died of the disease even though vaccinated. It has since been labelled parvovirus- 2, a variant strain of the original virus; thus, the creation of the KFII modified live virus (MLV) vaccine.
Yet, there still seem to be 'breaks' in the vaccine. Vaccinated dogs are still becoming infected, sometimes fatally. No vaccine is 100% effective -- there are many factors that can alter protection.
Parvo is caused by a very small virus that is capable of rapid mutation in order to insure its survival. It enters the body through the nasal and oral passages of an exposed dog; it then grows in the rapidly dividing cells of the intestinal lining.
The virus destroys the intestinal wall, rendering it incapable of absorbing nutrients. This damage gives rise to a profuse bloody diarrhea and increased gut motility leading to repetitive violent vomiting.
The mortality rate is high, especially in puppies less than 4 months of age. Death is usually due to the complications of severe dehydration and circulatory shock.
The virus also suppresses the immune system, depresses bone marrow and interferes in reproductive performance. In pups 8 weeks old and under the virus can also damage the heart.
Upon recovery from the active infection a large amount of virus can be shed in the stools 2 - 3 weeks post-infection. Parvovirus is quite stable in the environment; therefore, it is recommended to disinfect with a 1:30 dilution of bleach and/or new quaternary ammonia product, then rest the area for 30 days before a new pup is introduced.
Detection of the virus is usually done be presenting clinical signs. The diagnosis can be confirmed by an ELISA fecal antigen is detected in the stools. Supportive treatment consists of preventing secondary bacterial infections and most importantly, replenishing lost body fluids.
Low blood sugar and body fluid loss are the major problems to combat. Hospitalization, injectable drug therapy and intravenous fluids comprise the treatment regimen of choice.
There is no cure for paryo. The virus will run its course until expelled by the host's immune system. The only way to guard against the virus is by a preventative program. It is recommended to use a MLV vaccine, as they produce higher antibody titers and overcome maternal antibodies (antibodies ingested from the mother's milk - -important in neonatal protection) sooner.
Breeding pairs should be current on boosters within six months of mating. Puppies should start vaccination at 6 - 8 weeks of age with repeated boosters every 3-4weeks until 16-18weeks of age. It has been found that five percent of pups may not respond to the vaccine until 20 weeks of age.
If an outbreak has occurred in the face of an adequate vaccination program a titer way be evaluated and boosters carried out every month until an adequate titer has been obtained. This has proven helpful in the highly susceptible breeds such as Dobermans and Rottwielers).
Annual boosters are necessary; however, if there is an increased risk of exposure (show dogs, kennelled dogs) it is suggested to booster every six months.
Finally, parvovirus is by far the most fatal of the intestinal viruses; yet, there are other viruses which can cause gastrointestinal problems - - such as distemper, adenovirus, and a newer isolated corona virus.
Corona virus shows signs much like parvovirus, but usually is less severe and self - limiting in 3 - 4 days if the puppy's hydration is maintained. However, a corona viral infection can render a puppy more susceptible to a parvo outbreak. Therefore, a corona vaccination regimen should be implemented along with parvo boostering. Consult your veterinarian for further information.