Canine parvovirus, often simply called parvo, is a serious and highly contagious virus that affects most canids (dogs, wolves, foxes, coyotes, etc.). This potentially fatal disease attacks rapidly dividing cells in the body, particularly the cells of the intestines and bone marrow. Canine parvovirus causes severe diarrhea, vomiting, and lethargy.
There are various parvovirus strains that affect other species such as pigs, cats, and even humans.
Though they are the same type of virus, they are typically species-specific. Fortunately, canine parvo is not contagious to humans. In rare cases, certain strains may be contagious to cats.
How Parvo is Transmitted to Dogs
A dog becomes infected with canine parvo after coming into contact with microscopic particles of the virus. The virus is shed in the stool and is stable in the environment for a long time. The virus can easily be picked up on shoes and transported to other areas. A dog does not necessarily need to come into contact with stool to contract parvo. Parvovirus particles can live in the soil or other outdoor environments for five to seven months (even longer in cold climates as the virus can survive freezing temperatures). If the particles get on the dog's paws or fur and are then ingested, that dog can become infected.
Parvo most commonly affects puppies, but adult dogs can contract the disease if they are unvaccinated or immune-compromised.
Parvo enters the dog's system through the mouth. It then takes about three to seven days for the disease to become active in the body. Within a few days, the virus will begin shedding in the stool and can affect other dogs. Symptoms generally do not appear for yet another few days. The virus continues to be shed in the stool during the dog's illness and for a few weeks after recovery.
Symptoms of Parvo in Dogs
The typical symptoms of parvo are diarrhea, vomiting, loss of appetite and lethargy. The virus attacks rapidly dividing groups of cells in the body, specifically bone marrow and intestinal cells. After the bone marrow is affected, the white blood cell count drops and the immune system begins to shut down. When the intestinal cells are affected, the lining of the intestines becomes damaged and the body is no longer able to absorb nutrients or properly digest food. The result is nausea, vomiting, and severe diarrhea. Parvo dogs' diarrhea will typically be bloody with an odor far worse than normal feces.
Eventually, as the disease takes its toll on the body, the dog will become extremely weak and dehydrated. The dog may develop sepsis, an infection of the blood that can happen when the intestinal walls cannot act as a barrier against bacteria. Sadly, many dogs do not survive parvo. Early detection and intensive veterinary care are the best defenses against the disease.
Not all dogs with parvovirus will exhibit severe symptoms. In some cases, adult dogs may contract the disease with minor symptoms (or none at all) but will still shed the disease in the environment, potentially infecting other dogs. This is why appropriate vaccinations and routine veterinary care are so important for all puppies and adult dogs. Know that parvo can be prevented.
If you think your dog or puppy has the symptoms of parvo, contact your vet immediately.
A puppy with severe diarrhea will usually be suspected of parvo until proven otherwise. An adult dog with parvo symptoms and no vaccine history will usually be tested as well. The sooner your vet can assess your dog, the better his chance of recovery. Of course, this is the case with most diseases. Do not wait to see your vet if your dog has any signs of illness.
Your dog's medical history and symptoms play a big role in the diagnosis of parvo, but the final diagnosis is usually made after a lab test confirms the presence to the disease. Most vets will run an ELISA test on a stool sample to detect antibodies for parvovirus (indicating infection of the disease). Many vets have an in-house test kit in order to speed up diagnosis. If the ELISA test is positive, your vet will most likely recommend further lab work to assess the damage the disease has caused to the blood cells and organs.
Parvo Treatment for Dogs
Unfortunately, there is no cure for parvo. The cornerstone of treatment is supportive care. Ideally, this involves hospitalization and intensive nursing care. Home care is typically not effective for dogs that have become very sick. General treatment involves the following:
- Intravenous fluids to rehydrate
- Antibiotics to prevent sepsis
- Anti-emetics or anti-nausea drugs to combat nausea and vomiting
- Antacids to prevent further damage the stomach lining and esophagus due to nausea and vomiting
- Deworming is typically done during parvo treatment because the presence of intestinal parasites can increase the damage caused by parvo and hinder recovery.
Other treatments may be recommended depending on the dog's condition and the veterinarian's professional opinion. These may include anti-inflammatory drugs, antiviral drugs, plasma transfusions and more. In addition, lab work will need to be repeated periodically to motor the dog's overall condition.
If your dog is being treated for parvovirus, expect a hospital stay of about a week, give or take. Be prepared for a significant cost (several hundred to thousands of dollars depending on the case). In general, the survival rate with proper treatment is about 70-80%.
Home treatment is not generally recommended for parvo because it is not as effective. However, if cost is a major factor and an owner is dedicated, home care may be attempted in lieu of euthanasia. It is essential to about your dog's care and follow the medical recommendations. Survival is less likely with home care, but not impossible.
Recovery from Parvo
Once a dog has recovered from parvo, the treatment is not quite over yet. It is important to finish any course of antibiotics that your vet has prescribed. Your vet might also recommend continuing anti-nausea and/or anti-diarrhea drugs for a few days.
Expect your dog's stool to be loose for a few days as the intestinal tract is still healing. Re-introduce food gradually, ideally feeding a bland diet at first (as prescribed by your vet).
It is a good idea to bathe your dog well during and after the recovery process. Your dog will continue to shed parvovirus for about a month after recovery. Therefore, he should not be allowed in any public areas for that time period. In addition, he should be kept away from puppies and unvaccinated dogs.
Be sure to follow up with your vet during the recovery process in case any issues arise. Fortunately, once fully recovered, parvo dogs do not tend to have any residual health problems. More good news: after a dog recovers from parvo, he will be immune to it for at least a few years or possibly for life.
How to Protect Dogs From Parvo
Because parvo is such a deadly and contagious disease, prevention is of grave importance. Here's how to protect your dog or puppy from parvo:
- Vaccinate your puppies AND adult dogs. Be sure you see your vet for and that you report any signs of illness in a timely manner.
- Do not take your puppy to public places or around unknown dogs before he reaches 17 weeks of age AND is fully vaccinated. A puppy's immunity is unknown up to about 16 weeks of age, and vaccine-induced immunity is not fully effective until five to ten days after the vaccine.
- Become educated about parvo so you can detect early signs. While all dogs can be affected, puppies are most susceptible to parvovirus. All breeds are at risk, but a few breeds that might be predisposed include the Rottweiler, Doberman Pinscher, and American Pit Bull Terrier. Also remember that adult dogs can contract parvo if they are unvaccinated or immune-compromised.
Because parvovirus is highly contagious to other dogs, measures must be taken to decontaminate areas where a parvo positive dog has been.
Even if a parvo dog has spent a brief time in an area and has not defecated there, you must decontaminate the area. Remember that the parvovirus can remain on a dog's paws and fur and can be transported this way.
At the vet hospital, parvo dogs are placed in isolation and veterinary staff cleans up with a bleach solution or a disinfectant that is known to kill the parvovirus. At home, you can make your own bleach solution. In order to be strong enough to kill parvovirus, the solution must be one part bleach to 32 parts water or stronger. Once mixed, the solution is only effective for 24 hours. It is important to know that other household chemicals will NOT kill parvovirus.
When decontaminating inside your home, the degree to which you need to disinfect will depend upon other dogs that live there. Generally, parvovirus will not live indoors for more than a month or so, but you should still be sure to thoroughly clean the area (you don't have to bleach your carpets, but be sure to clean them well). Soiled bedding should be thrown away (seal it in a plastic garbage bag first) or washed in hot water and bleach. If there are puppies or unvaccinated dogs living in the home, they should be kept away from contaminated indoor areas for at least a month.
Outdoor areas are much more difficult to disinfect. Parvovirus can live outdoors in non-freezing temperatures for five to seven months, depending on conditions. Freezing temperatures actually protect the virus, so it tends to live longer in cold climates. In an effort to minimize contamination outdoors, you can water the area to dilute the virus. Bleach can be applied to areas without grass or plants. Overall, your best bet is to keep puppies and non-vaccinated dogs away from the area until you can be sure the virus has died off.