Parvovirus in dogs

Written by Dr Andrew Miller MRCVSDr Andrew Miller MRCVS is an expert veterinary working in the field for over 10 years after graduating from Bristol University. Andy fact checks and writes for Pure Pet Food while also working as a full time veterinarian. Pure Pet FoodPure Pet Food are the experts in healthy dog food and healthy dogs featured in media outlets such as BBC, Good Housekeeping and The Telegraph. Working with high profile veterinary professionals and nutritionists, Pure Pet Food are changing dog food for the better. - Our editorial process

Canine Parvovirus (CPV) was first recognised in Europe in 1978, making it a relatively new disease amongst the doggy population. Yet within two years this highly-infectious and lethal disease had gone global, and now CPV can affect any dog in any country.

Most of us know that parvovirus in dogs can be deadly, so what can be done to prevent this vicious disease and what are the signs your puppy is affected? Here’s everything you need to know about parvovirus in dogs including how to prevent it infecting your dog and what treatment is available.

What is parvovirus in dogs?

Canine parvovirus is a highly contagious and often fatal virus that can affect dogs and other canine species, like foxes and wolves. It makes dogs incredibly dehydrated, weak, and listless and causes severe vomiting and diarrhoea.

Although we often associate parvovirus with puppies, any dog of any age or breed can be affected. However, puppies are especially vulnerable to this infection because they do not have a fully developed immune system to protect them.

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Are there different types of parvovirus?

There are two types of parvovirus in dogs, CPV1 and CPV2 however there are numerous different strains of these two types.

There are also two forms that the virus can take, intestinal or cardiac, according to the area in the body affected by the virus.

Intestinal parvovirus

This is the most common form of parvovirus in dogs. This strain of the virus attacks the cells in your dog’s gastrointestinal tract, causing inflammation in their intestines and an inability to absorb fluid and nutrients from their food.

This is because the virus attacks the villi, which are like little fleshy bristles on the inside of the intestines which help to absorb nutrients from food into the bloodstream. This also means that your pooch is at risk of sepsis if the virus enters their bloodstream through their intestines.

Intestinal parvovirus will also cause a host of symptoms similar to other gut-related illnesses. These include sudden vomiting and diarrhoea, which may be bloody, as well as loss of appetite.

Cardiac parvovirus

Cardiac parvovirus in dogs is much rarer but even more severe. This strain of the virus is usually seen in very young puppies, and it will attack the cells in the dog’s heart muscle. It causes inflammation of the heart (myocarditis), and it can cause heart failure.

Not as much is known about the effects of cardiac parvovirus because it is far less common and not as widely studied. However, symptoms of cardiac parvovirus include lethargy, a swollen abdomen, as well as rapid, short breaths and difficulty breathing. Dogs suffering from cardiac parvovirus also commonly lose their appetite.

The effects of parvovirus in dogs

If infected with parvo, your pooch can’t absorb as much fluid or nutrients from their food so they quickly become dehydrated and weak. Severe dehydration can cause septic shock and can be fatal in as little as two days if left untreated.

Even if your dog survives parvovirus, it can still have a lasting impact on their health. Dogs who have suffered from intestinal parvovirus seem to be at much greater risk of developing gastrointestinal illness and chronic gastrointestinal disease later in life. Not only are they more likely to develop problems with their gut, but any illness they develop will also usually be more severe than in a dog uninfected by CPV during their lifetime.

Cardiac parvovirus can damage the heart muscle of your dog, causing long-term cardiac damage and making them vulnerable to cardiac issues like congestive heart failure later in life.

Parvovirus can be fatal, but provided your dog is given prompt veterinary treatment they have a good chance of survival, and will usually go on to live a full life expectancy and a normal, healthy life.

Is parvovirus contagious?

Parvovirus is highly contagious and can quickly spread between dogs.

An infected dog will shed viral particles which can contaminate other pups, and the virus often spreads through close contact between dogs as well as through infected poo.

Tons of infectious parvovirus particles are expelled in the faeces of a dog with parvo. If a healthy dog sniffs or eats an infected dog’s poo, then they can become infected themselves. Your dog can still contract parvovirus if they just sniff the ground or grass that has been contaminated by feces, even if the poo itself has been cleaned up some time ago.

Worryingly, dogs infected with parvo are usually contagious before they show any symptoms. That means your pooch could be spreading the disease while you’re unaware they’re even infected. Dogs can spread parvovirus within 3 or 4 days of infection, meanwhile it can take up to a week after infection for your dog to show any sign of illness.

Even a dog who has been treated and recovered from parvovirus will continue to shed infectious particles for at least 14 days after they have recovered. This is why it's important to isolate an infected dog while they are being treated and during recovery.

Other forms of transmission

Parvovirus is a very hardy virus that’s difficult to destroy. It’s resistant to hot and cold as well as most household cleaners, meaning it can survive in the environment for months.

Infectious viral particles could be found in soil that’s been contaminated by an infected dog's faeces, or it can survive on surfaces and objects that an infected dog has been in contact with. For example, floors, sofas, beds, and toys. These particles can even survive on a human’s hands or clothes and be spread amongst dogs.

It’s thought that the virus can survive at room temperature for months, and over a year in a moist environment out of direct sunlight.

Dogs aren’t the only animal that can catch and spread parvovirus because foxes can too. If there is an infected wild fox it could spread the disease between gardens or in its faeces which your dog might find on walks.

As you can see, parvovirus is highly contagious, spreads quickly, and is hard to destroy. This makes prevention very important because your dog can come into contact with the virus easily.

Can a cat get parvo from a dog?

Although parvovirus usually only affects specific species, cats can catch parvovirus from dogs. A mutated strain of canine parvovirus is able to infect cats, plus your kitty is also at risk of feline parvovirus (FPV) which is specific to cats.

Although cats can catch parvo from dogs, the reverse is not true. So your pooch is not at risk of catching parvo from a cat.

Can humans catch parvo?

No, humans cannot catch parvovirus from their dog, and there have never been any cases of canine parvovirus in humans.

There are dozens of strains of parvovirus in the world, and some of them can infect humans. Usually though, parvovirus is limited to certain species. For example, canine parvovirus infects dogs, wolves, hyenas, foxes, and other canines. Meanwhile, porcine parvovirus affects pigs.

Although humans can’t catch parvovirus from their dogs, they can transmit the virus between dogs.

If you stroke an infected dog, or touch a contaminated surface or object such as a dog bed or toy, you can then carry the disease on your hands or clothes which could go on to infect any other dog you come into contact with. Even if you’ve stepped on poop or dirt that’s contaminated with parvovirus, the disease can remain on your shoes and spread wherever you walk, or to any dog that sniffs or licks your shoes.

That’s why it’s important to thoroughly wash your hands with soap and water after stroking a dog and after cleaning up after one.

Are some dogs more at risk of parvovirus?

Puppies and unvaccinated dogs are at greater risk of parvovirus and are more likely to suffer severe illness and death because they do not have the antibodies to protect them against infection.

Puppies are especially vulnerable because they not only do not have the antibodies to fight off the virus, but they do not have a fully developed immune system to protect them.

Very young puppies might have some immunity from their mother’s milk, provided their mother was vaccinated against parvo. However, this immunity wears off after a few weeks leaving them vulnerable to infection.

Some breeds seem to be more at risk of being infected with parvovirus and are more likely to suffer from serious illness if they catch it. These high-risk breeds include:

Parvo in dogs symptoms

Often the first sign that a dog has been infected with parvovirus is lethargy and a reluctance to eat. Puppies affected with parvo might be happy and playing one day, then suddenly bed-bound, listless, and unresponsive the next.

The symptoms of parvo in dogs includes:

Vomiting and diarrhoea caused by parvovirus will often have a foul odour. It will smell much worse than any vomit or diarrhea your dog has previously had, and much stinkier than their usual faeces. They could also have blood in their vomit or diarrhoea.

If you have a puppy suffering from sudden vomiting, especially if they are unvaccinated, you should take them to the vet. Parvovirus is deadly if left untreated and most deaths occur within 48 to 72 hours of symptoms appearing. This virus develops quickly, which is why it is so important to take your puppy to the vet as soon as they show any signs of illness.

How is parvovirus in dogs diagnosed

If your dog shows any symptoms of parvovirus, it’s important you contact your vet immediately. They might ask you to stay in the car with your pooch if they suspect parvovirus. This is to protect the other pets that are visiting the practice and prevent the spread of infection.

The vet will conduct an ​​enzyme-linked immunosorbent assay test, which means they will take a swab of your dog’s faeces and test it for signs of parvo. The test only takes ten minutes and it’s very accurate. However, a negative test does not always mean a puppy is clear of parvo, because they might be infected but not yet shedding viral particles at the time of testing. In which case, your vet may begin treatment according to their symptoms to prevent their condition worsening and test them again later.

How to prevent parvovirus in dogs

It’s incredibly difficult to prevent parvovirus in dogs because the virus can contaminate an environment for months and it’s resistant against most household cleaners and heat. It’s also highly contagious, so it is very easy for a dog to pick up parvo from another pooch, poo, or even the clothes or hands of a human that’s petted an infected dog.

You should always wash your hands after petting another dog to help prevent the spread of disease. If your pooch or a visiting dog has parvo, you must clean the floors and surfaces of your home with a diluted bleach solution to kill off parvovirus. Keeping up good hygiene will prevent reinfection and help to prevent the virus from spreading.

While your puppy is unvaccinated and vulnerable to infection, you must take great care to make sure they do not come into contact with the virus. This is why you’re advised not to take your puppy outside or let them meet other dogs until they have received all of their puppy vaccinations.

Pups can play with vaccinated adult dogs and other partially-vaccinated puppies relatively safely. However, your puppy should avoid any unvaccinated dogs or unfamiliar dogs whose vaccination history you do not know because they could be carrying the disease.

Prevention is the best medicine, especially in the case of a virulent and vicious virus like parvo. But, unless you keep your dog at home their entire life and never come into contact with other dogs or their poo, then you can’t prevent parvovirus forever without vaccination. It also isn’t fair on your dog to keep them isolated forever!

Vaccination is important because it’s a safe and effective way of protecting your dog against disease, allowing them to explore the world and meet other pups without worry of contracting a potentially lethal disease.

Parvovirus vaccines for dogs

Parvovirus vaccines are incredibly effective at protecting dogs from parvo and preventing the spread of the disease. The vaccination essentially introduces a harmless version of the virus into your dog’s body and trains their immune system to fight the disease without them having to suffer infection and illness.

These vaccines are usually given when a puppy is 6 to 8 weeks old, and a second vaccine at least 2 weeks later. They will need booster vaccinations for the rest of their life to maintain their immunity against parvo. Your pooch will get their first booster shot at one year old, after that, they only need a booster every three years.

If you miss a vaccination in your pup’s core vaccines, your vet will suggest you start the series again.

It’s important to remember that your puppy won’t be immediately immune to parvovirus after their jabs. It will take two weeks after their final vaccine for their body to develop the antibodies they need for full protection against the disease.

Treatment for parvovirus in dogs

If you suspect your pup has parvo, they will require treatment as soon as possible to give them the best chance of survival. Parvovirus is often fatal if left untreated, and sadly, it can still be deadly to dogs who receive veterinary care.

However, prompt treatment from a vet improves your dog’s chances of survival astronomically. If your pup is treated immediately their chances of survival are high, estimated to be between 68-92% or 75-80%.

As with many viruses, there is no specific cure for parvovirus. Your vet will instead provide rigorous supportive treatment to treat your dog’s symptoms and prevent complications or secondary infection which is what proves fatal.

The aim of treatment for parvo is to help support your dog’s body and strengthen their immune system so that they can fight off the disease. Your dog will need to be kept in a veterinary hospital for a few days to receive round-the-clock treatment and observation.

If a puppy survives beyond 72 hours after showing symptoms, they will often recover. It often takes a week of care in a veterinary hospital for a pooch to recover. However, they will still shed infectious particles for 14 days so they must stay in isolation once they’re home to prevent infection to other dogs.

How is parvovirus in dogs treated

One of the key treatments your dog will receive is intravenous fluids. This will prevent dehydration, which will weaken a dog and could be fatal within 2 or 3 days. Since your pup will be losing a lot of liquid in their vomit and diarrhoea, but will be unable to eat or drink, it’s vital they receive plenty of IV fluids to keep them hydrated.

IV fluids also contain electrolytes which will provide energy to allow your pup’s body to function, which is especially important while they are too poorly to eat. An intravenous drip is also useful for administering medications quickly into your pooch’s bloodstream.

One of these medications will be antiemetics to reduce nausea and prevent vomiting. Once a dog’s nausea is under control, they might try eating again. Trying to encourage a dog to start eating aids their recovery because it means they can start taking in more nutrients to provide the energy they need to recuperate. During recovery, your dog will need a highly digestible food that’s packed full of nutrients so your puppy can take in plenty of healing nourishment. Sometimes, a dog will be fitted with a feeding tube to provide them with nutrition while they’re unwell.

Your pup might be given antidiarrheals to prevent diarrhoea, helping their gut to rest and to prevent any more loss of fluids.

Parvo also reduces your pup’s white blood cells and weakens their immune system, making them vulnerable to secondary infections. Your vet will provide your dog with antibiotics to help prevent any bacterial disease or infection that could further weaken your pooch and put their life at risk.

Caring for dogs with parvo is very labour intensive as they will need their IV fluids changed regularly and all mess from their vomit and diarrhea must be cleaned up. Their condition can deteriorate rapidly, and they will be checked every hour or two while they are recovering. Your pooch will be in isolation and all veterinary nurses caring for them will wear PPE to prevent the virus spreading to other dogs.

Once your dog is home

When your dog is well enough to come home, they’ll still need to be nursed and kept in isolation for the rest of their recovery.

You need to make sure your pooch always has access to clean, fresh water and drinks plenty of it. You should also feed them little and often with a bland meal or a highly digestible food.

Put down puppy pads or old towels for your pooch to toilet on, because they will need to wee and poo suddenly and more frequently, making accidents likely. Their bowel movements will return to normal within a few days and once they’re eating solid food.

You shouldn’t walk your dog while they’re recovering to conserve energy and allow their body chance to rest and recuperate. Plus, taking them outside puts them at risk of picking up another infection or illness while their immune system is weak. Just like a human needs bed rest after they’ve been unwell, your pup needs plenty of rest while they recover!

  1. Feline Parvovirus (FPV)
  2. Long-term effects of canine parvovirus infection in dogs PLOS One, 13, (3), March 2018, doi:10.1371/journal.pone.0192198