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.
What Is Parvo?
Canine parvo is a virus that causes severe diarrhea, vomiting, dehydration, and lethargy in dogs but is not contagious to humans. Parvo refers to various virus strains that affect other species, and although they are the same type of virus, they are typically species-specific. In rare cases, certain strains may be contagious to cats. If you think your dog or puppy has the symptoms of parvo, contact your vet immediately.
Symptoms of Parvo in Dogs
Parvovirus is so insidious because it attacks rapidly dividing cells in an animal's bone marrow and intestines. Once the bone marrow is affected, the animal's white blood cell count drops, raising the risk of infection, and the immune system begins to shut down. When the intestinal cells are affected, the lining of the intestines become damaged and the body is no longer able to absorb nutrients or properly digest food. The result is nausea, vomiting, dehydration, and severe diarrhea.
Parvo typically causes diarrhea that is bloody with an odor far worse than a dog's normal feces.
As the disease takes its toll on the body, the dog will become extremely weak and dehydrated. The dog may develop sepsis, which is 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 may infect other dogs.
Parvo can be a frightening prospect for dog owners, but it can be prevented with routine veterinary care and keeping your dog's vaccinations up to date.
Causes of Parvo
Parvo most commonly affects puppies, but adult dogs can contract the disease if they are unvaccinated. A dog whose immune system is compromised (due to another medical condition) is also at risk for parvo.
A dog becomes infected with canine parvo after coming into contact with microscopic particles of the virus from contaminated feces. The virus 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. It's at this point that it 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.
Parvovirus is stable in the environment for a long time and remain viable in areas where dogs play and relieve themselves. Your shoes can easily pick up the virus and transport it to other areas. A dog does not necessarily need to come into direct contact with feces to contract parvo.
Parvovirus particles can live in the soil or other outdoor environments for five to seven months and even longer in cold climates since 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.
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 of the disease.
Most veterinarians will run a test on a stool sample to detect antibodies for parvovirus, which will indicate whether an animal has been infected. Many vets have an in-house test kit in order to speed up diagnosis, where results are usually available within 15 minutes.
If the parvo 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.
The sooner your vet can assess your dog, the better its chance of recovery. Do not wait to see your vet if your dog has any signs of illness.
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 to the stomach lining and esophagus due to nausea and vomiting
- Deworming 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 monitor 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 to 80 percent.
Home treatment is not generally recommended for parvo because it is not as effective. However, if the cost is a major factor and an owner is dedicated, home care may be attempted in lieu of euthanasia. It is essential to know about your dog's care and follow medical recommendations. Survival is less likely with home care, but not impossible.
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. Reintroduce food gradually, ideally beginning with a bland diet 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, it should not be allowed in any public areas for that time period. In addition, it should be kept away from puppies and unvaccinated dogs.
Fortunately, once fully recovered, parvo dogs do not tend to have any residual health problems. More good news: After a dog recovers from parvo, it will be immune to it for a few years or possibly for life.
How to Prevent Parvo
Because parvo is such a deadly and contagious disease, prevention is crucial. Here's how to protect your dog or puppy from parvo:
- Vaccinate your puppies and adult dogs. Be sure you see your vet regularly 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 it 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 10 days after the vaccine.
- 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 to parvo include the Rottweiler, Doberman pinscher, and American pit bull terrier.
Because parvovirus is highly contagious to other dogs, measures must be taken to decontaminate areas where a parvo positive dog has spent any time.
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 special disinfectant that is known to kill the parvovirus.
Other household chemicals will not kill parvovirus. If you wish to make a bleach solution at home, you can do so, but consult with your vet first. If you want to use a cleaner besides bleach, contact your vet about the right products and where to buy it.
Generally, parvovirus will not live indoors for more than a month or so, but you should still be sure to thoroughly clean the area. Soiled bedding should be thrown away, sealed in a plastic garbage bag before doing so, 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 above freezing temperatures for five to seven months, depending on conditions.
It is only safe for your dog to return to bleached areas after they are completely dry. 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.