Parvo in Puppies

Parvo in puppies is a viral infection that causes severe vomiting and diarrhea in dogs. It is a serious disease and sometimes can be fatal.

Parvovirus is an extremely deadly viral disease. It is therefore important for dog parents to learn more about this disease so that we are better informed and know what to do in the unfortunate event that our dogs show signs of parvo.

This page will look at the following:

What exactly is canine parvo?
How is parvo spread?
What are the two forms of parvo?
How is parvo diagnosed?

Please also visit our page on Parvo Symptoms to familiarize yourself with the various clinical symptoms of parvo in puppies and dogs.

For information on conventional and some natural parvo treatments, please visit Treatment for Parvo in Puppies.

Parvo in Puppies - What Exactly is Parvo?

Dog parvo, or canine parvovirus (CPV), is a viral disease that is highly contagious and can spread quickly to dogs that are not immune from the disease. The current strain of parvovirus (CPV2) was discovered in 1978, and within 2 years had spread all over the world.

Parvovirus can affect dogs, wolves and foxes; but it cannot infect other animals and cannot be spread from dogs to humans. However, other animals and humans can pass the virus onto dogs.

Parvovirus affects mainly puppies and younger dogs. (However, older dogs can catch the parvo virus as well.) Puppies between weaning and up to six months of age are the most at risk. Once a puppy is infected, he has a 50-50 chance of survival - even with medical treatment. The critical period is the first five days of infection. If timely treatment and care is given to an infected puppy, and if the puppy can get past the first five days, he will probably live and become immune to the virus. If the puppy is left untreated, dog parvo can kill him in 2 to 3 days.

Recovery from the disease depends on the virulence of the strain, the amount of virus ingested, and the breed. Some breeds (e.g. Doberman Pinschers, German Shepherds, Pit Bulls, Labrador Retrievers and Rottweilers) are particularly susceptible to parvo. Even worse, once infected, these breeds seem to succumb to the virus faster than other breeds and they seem to have a lower chance of recovery.

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Parvo in Puppies - How is Parvo Spread?

Canine parvovirus is spread by infected dogs - some adult dogs infected with the virus do not get sick; they are just carriers. Infected dogs shed the virus (mainly in their stools and vomit) in massive amounts during the two weeks following exposure, contaminating yards, playgrounds, and other places where dogs frequent. In addition, canine parvo can be transmitted by people (on their clothing or shoes), or by birds (on their feet) if they ever step on some contaminated soil. Inside the house, the virus can survive on objects such as clothing and carpets for a long time (over 5 months). Household pests such as cockroaches can also carry the virus from place to place.

Unlike the distemper virus, the canine parvo virus is not enveloped in fat, which means it is especially hardy in the environment and extremely difficult to eliminate. The virus is also shed in large amount by infected dogs.

As you can imagine, a dog can therefore get infected by the parvo virus virtually anywhere!

So why do some dogs with the parvo virus get sick while others don't? Infection depends on several factors, namely:

the dog's age, health condition, and breed;
whether the dog has been vaccinated against the virus, or whether he has previously been infected.
whether the dog has been exposed to a large number of virus.

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Parvo in Puppies - Two Forms of Canine Parvovirus

The two forms of canine parvovirus are intestinal and cardiac.

Intestinal Parvo

Intestinal parvo (known as enteritisis) is more common than cardiac. A dog can get the parvo virus by direct contact through the mouth. For example, by licking soil or pavement contaminated with the virus.

Once the virus has entered the dog, it starts replicating in the dog's throat tissues, and then moves to the bloodstream. It then attacks and destroys the dog's intestinal lining, as well as the lymph nodes and bone marrow.

The intestinal lining takes about 5 days to grow back. Therefore, during those 5 days, the dog is left without any method of digesting, and is left with a very weakened intestinal wall so bacteria can get across it. Bleeding into the intestine will also occur and the wall will be very inflamed.

Cardiac Parvo

This is less common and affects mostly young puppies, infected either in vitro (from their mother who is not vaccinated against parvo), or within the first 2 months after birth. Cardiac parvo causes myocarditis (inflammation of the heart and damage of the heart muscle). The cardiac parvo symptoms are sparse and can come on rather rapidly. Usually, a puppy with cardia parvo will have breathing difficulties, followed by congestive heart failure, and sudden death.

Those puppies that manage to survive cardiac parvo often end up with some form of heart problems and die young.

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Parvo in Puppies - Diagnosis

Because of the common symptoms of GI disorders (vomiting, diarrhea), many sick puppies are misdiagnosed as having been infected with parvo. Of course, not all cases of bloody diarrhea and vomiting are caused by parvo in puppies.

Diagnostic tests for parvo are necessary to ascertain whether a puppy in fact has parvo or not. The tests include:

Complete Blood Count: Dogs with parvo typically have very few white blood cells. Although this alone cannot firm parvo, it shows high possibility nonetheless.

Clinical Signs: Since intestinal parvovirus affects a dog's digestive tract, dogs with parvoviral enteritis have severe vomiting and diarrhea. Other signs include fever and enlargement of the lymph nodes.

Fecal Antigen Test: If parvo virus is found in a dog's fecal matters, then the dog is diagnosed with canine parvovirus.