What is Parvovirus and why does it make my dog sick?

“Parvo” is a viral infection that affects dogs, and is shed by infected dogs in their stool (poos). A dog or puppy that is not up to date with vaccinations may be infected with the virus – by ingesting (orally) virus particles (one gram of dog poo contains enough virus particles to infect over 10 million dogs) in a contaminated environment. Dogs do not have to have direct contact with each other to spread the virus.

Parvovirus is a very stable virus – it can survive for a very long time in the environment, particularly in warmer weather, which means that it is easily spread between dogs through contaminated shoes, clothes, bowls, grass, soil, bedding etc. Dogs lick and put their mouths on a lot of things in their environment, they don’t have to actually eat something to get parvo.

Parvovirus has a 3 to 7 day incubation period, meaning that a dog or puppy may not show signs of illness until days to a week after it become infected. Occasionally dogs may be infected with parvovirus, and not show signs of illness, but still be shedding the virus in their poos.

The virus damages the intestines, resulting in vomiting and diarrhea, fluid loss and dehydration, then shock and death. Alternatively, death may occur due to bacterial toxins that result when the damaged intestines develop a bacterial infection due to loss of the intestinal barrier. Parvo is a very serious and often deadly infection in dogs.

What are the signs of Parvo?

There are several possible signs of parvovirus infection in dogs. A dog or puppy with parvo may exhibit one, some, or all of these signs, depending on the stage and severity of infection. These signs can also be seen with other illnesses in puppies or dogs, such as parasite infection, gastroenteritis, and foreign body obstruction, so it is important that a parvo test is carried out to ensure that the correct diagnosis is made. Signs may include:

• Diarrhoea (usually severe and bloody)
• Vomiting
• Loss of appetite
• Rapid weight loss
• Lack of energy (lethargy/depression)
• Discomfort in the abdomen

What do I do if I think my puppy/dog has Parvo?

If your puppy or dog is showing the signs of parvo, contact the clinic to book an appointment for a parvovirus test. This test involves taking a poo sample. The test takes about 10 minutes to give a result. We will request that you do not bring your puppy into the clinic, but leave it in your vehicle, as if the puppy has parvovirus it will be contagious to other dogs.

We would also prefer if you were able to call the clinic from your vehicle once you arrive at the clinic, and we will come out to you, as you yourself may be carrying virus particles on your skin, clothes or shoes that can cause contamination of the clinic. Be prepared that getting your dog or puppy tested for parvovirus is going to cost you about $100-150.

The test will give a positive or negative result, similar to a pregnancy test. It is important to realise that no test is perfect, and if a dog or puppy has been vaccinated within in the last 5 to 12 days, it may show a false positive test. Similarly if the dog or puppy is in the later stages of infection, it may no longer be shedding virus particles in its poos, which will result in a false negative result. For this reason results are interpreted by the vet in combination with the history of the dog, and the signs the dog is exhibiting.

My puppy has tested positive for Parvo, what happens now?

There is no cure for parvovirus, the only treatment that can be given is to support the dog until its immune system manages to overcome the virus. Unfortunately, even with the most expensive treatment, only 50% of dogs and puppies will survive a parvo infection. Without treatment, the dog or puppy will die.
Many owners have to make the heart-breaking decision to euthanase their dog or puppy if they cannot afford treatment, the animal is too sick, or if they do not respond to treatment. In these cases the decision to euthanase is made for the welfare of the dog or puppy, as death due to parvo virus is a prolonged and painful way to die.

The best treatment for parvovirus involves admitting the animal to a special isolation ward of the veterinary hospital, and administering intravenous fluids, antibiotics, anti-vomiting medication and in some cases, canine plasma. The cost of this treatment is upwards of $1000.

If this is not an option financially, some owners may choose to attempt conservative treatment at home, administering electrolytes, antibiotics and anti-vomiting medication dispensed by the vet. This is a less effective form of treatment, and is usually only suitable if the puppy is older, or is early in the infection and not too sick. The cost of this treatment is upwards of $250.
Parvovirus can last for up to 2 years in the soil, so if you have had a dog with parvo on your property in the last 2 years, it is not recommended that you get a puppy or an unvaccinated dog, or have one visit.

My puppy/dog is healthy, how do I protect it from Parvo?

Prevention is always much better and cheaper than cure. Vaccination is the only way to protect your puppy or dog from parvovirus. Puppies should receive a vaccination every 3-4 weeks from 6-8 weeks of age (depending upon when they are weaned), with the last parvo vaccination being given at or after 16 weeks (4 months) of age. We recommend waiting a week after this final vaccination before considering a puppy to be fully vaccinated, to give time for the vaccination to do its job.
It is important to note that if a puppy has received only some of its vaccinations, it can still get parvovirus. For this reason we recommend that puppies are only socialised with fully vaccinated dogs, or other puppies at a similar level of vaccination in a puppy class, in a non-contaminated environment.

Walking puppies or a dog that have not finished all of their vaccinations, or taking them to dog parks or other public places is not recommended.

Adult dogs need to be vaccinated regularly against parvovirus (every 1-3 years depending on the vaccine used and their risk level). If they were not vaccinated properly as puppies, or missed a vaccination, then they will need to have two vaccinations 3-4 weeks apart. Leptospirosis and kennel cough vaccinations need to be given once a year to adult dogs.