What is Parvovirus?

A sick dog needs a vet.

What is Parvovirus? The Parvovirus is a highly contagious and potentially fatal virus most commonly transmitted between dogs through the direct or indirect contact with infected faeces. The primary symptoms are mostly associated with those of dehydration, such as vomiting and diarrhoea, as well those of bacterial infections, like fever. Vaccination is the most efficient and common prevention as the risk of mortality risk is greatest amongst puppies.

What are the first signs of Parvo?

The most prominent symptoms or Parvo are:

  • Vomiting
  • Bloody diarrhoea
  • Lethargy and collapse
  • Loss of appetite
  • Dehydration
  • Fever

Any dog owner should be aware of the first symptoms related to Parvo since its rapid spread makes it quite time sensitive.

These symptoms tend to appear between 3 days to a week from the moment the virus has entered the dog’s body. Following a brief incubation period, it will quickly replicate and spread throughout the bloodstream.

There are no particular characteristics to the vomit, but the stool will most often appear watery, tinted with blood or have a more yellow tone, along with a pungent smell. These quickly lead to dehydration which may be accompanied by signs of fatigue and loss of appetite.

Watery Stools rather than solid and a definitive Lethargy show signs of illness

On the other hand, signs of fever will warn of damage to the dog’s immune system. This is most frequently associated with a drop in white blood cell concentration in the blood. The function of these white blood cells is to protect the body against any incoming harmful invaders and infectious diseases. Such a drop will therefore leave dogs more susceptible to illnesses.

Lethargic Dog i.e. no energy

If any such symptoms are observed simultaneously, or in succession, a veterinarian should promptly be consulted to carry out a diagnosis and treatment, if necessary.

If the symptoms dissipate around 4 days after they have first appeared, the risk of mortality tends to drop significantly, and a full recovery may lead to increased resistance to the parvovirus in the future. However, such chances of healing remain very slim without medical intervention, particularly with younger puppies.

How do dogs get parvo?

The main point of entry for the virus is through the dog’s mouth. Since dogs are constantly sniffing around, eating off the ground or cleaning themselves after a walk outside, the exposure is prominent and hardly avoidable.

Unfortunately, this leads straight to the most vulnerable part of the body: the digestive system. It is precisely within the gastric and intestinal tracts that the virus is most destructive as it damages its lining and inhibits its ability to absorb nutrients.

The Parvo virus is highly contagious amongst dogs as any direct or even indirect contact will allow it to be transferred.

As the dog may succumb to severe dehydration or bacterial infection from its weakened immune system. Both fatal examples contribute to the appearance of the aforementioned symptoms in various ways and hence call upon the owner’s vigilance in their detection and potential combinations.

The faeces or vomit of infected dogs may be sniffed by a dog directly, or merely picked up by an owner’s shoes

Dogs will lick many things simply out of curiosity

In addition, it is also highly resistant to harsh environments and cleaning products as it may survive up to half a year in the grass of your dog’s favourite park. Once a place or material has been contaminated, only the use of bleach may help to return it to a dog-safe zone. Hence, even pet shops, Veterinary hospitals or any establishment associated with dogs may themselves be susceptible to contamination.

How to treat Parvo?

For cases of acute dehydration, intravenous drips can be used to replenish the body with all the water and nutrients lost from vomiting and diarrhoea, as well as to allow the digestive tract to recover before allowing the dog to eat and drink on its own.

Antibiotics therapy might be used to fight off any pre-existing infection or to help the immune system along its recovery. Similarly, blood transfusions might be recommended in cases where the parvovirus infected the bone marrow. This would aim to increase white blood cell concentration in the bloodstream and restore a well-functioning defence system to prevent further infections.

Treatment for dogs suffering from Parvo will vary depending on the severity of the illness. However, most cases will require a stay in a veterinary clinic to aid the healing process and facilitate rehabilitation.

Professional treatment also ensures that infected dogs are safely isolated to prevent the spread of the disease to other dogs. An early release could place other dogs at greater risk and even decrease the dog’s chances of survival.

Once Parvo has been successfully treated, the previously infected dog develops a life-long immunity to the virus. However, this should not dissuade owners from remaining aware of any potential symptoms their dog might be experiencing, and more importantly even, of their own role in the spread of Parvo to other dogs.

Can Humans catch Parvo?

The parvovirus, which dogs are susceptible to, cannot be transmitted to humans. It does not tend to spread across different animal species either, although the canine type we are here concerned with appears to have originated from the feline parvovirus most common amidst cats where it is even more aggressive.

Nevertheless, it is also important to note that humans may easily aid the transfer of the virus between other dogs, from the ground by means of their shoes, or from the direct contact of their clothes or hands with an infected dog.

Can my Puppy get Parvo?

It is recommended for a puppy to turn 6 weeks old to get a Parvovirus vaccination and return every 2 weeks until it grows older. The length of such a cycle is very much determined by the breed of dog as larger breeds may need to keep regular tests and jabs until they are 6 months old, whereas smaller ones may only uphold it until they are 4 months of age.

Testing for Parvovirus

Unvaccinated puppies, or a puppy that has only had their very first injection, does not have any protection against the parvovirus or any other diseases we vaccinate against. Your puppy will not be safe to go out for a walk or meet other dogs until 1-2 weeks after they completed their first vaccination course, in the meantime:

  • At home and in the garden. Your puppy is safe to go into the garden as long as no unvaccinated dogs have frequented recently.
  • Public places. You can take your puppy out into public spaces, but make sure that you carry them. Do not put them down to sniff around the ground
  • Puppy classes. As long as your puppy is healthy, you can enrol in a puppy class. The learning benefits will far outweigh the very small risk of catching parvovirus from another puppy at the class.

How to prevent Parvo?

The most effective and common prevention is vaccination. As with humans, the earlier the vaccine is administered, the safer your dog will be.

For any additional information relating to a specific breed of dog, it is always best to refer to a veterinarian who will inform on the best course of action. In any case, parvo shots are amongst the most common vaccines administered so any visit to a clinic should remind the owner of such a case.

No matter the breed, it is in the puppy’s fragile infancy that such action needs to be taken to avoid the most fatal cases of the parvovirus. Such care should also be extended throughout the dog’s life, as yearly booster shots should become a common habit.

Additionally, if your dog has had Parvo and potentially contaminated your home or other known public areas, it is important to take cautionary measures to prevent any further spread. Using diluted bleach to disinfect homes is highly recommended to eradicate any last trace of the virus indoors and on clothes (don’t bleach your clothing though, just wash it), allowing you to protect the next dog you cross in the street from Parvo.

The History of Parvovirus

The canine parvovirus immediately rose to prominence as a fatal and highly contagious disease which spread across the globe in a matter of months. The epidemic, which ensued from its appearance in 1976, led to widespread gastro-intestinal illnesses in dogs, with the most severe cases observed amidst puppies.

Puppy with intravenous drip in a veterinary clinic

Whilst dog owners grieved their pets, it was found that the virus, most commonly referred to as ‘Parvo’, could also spread to wild canines and even certain wild animals. The surprising reach of the virus allowed it to be identified as a close relative to the feline type. It is known as the feline panleukopenia virus whose mutations led to the establishment of the type 2 canine parvovirus, CPV, which we know to most commonly infect pet dogs.

Although its width barely stretches past a millionth of a millimetre, one may not be fooled by its apparent simplicity as its ability to quickly duplicate and evolve shapes it into the deadly pathogen it is.

Parvovirus B19

Its main target areas in the body are the hotspots of cell division where new cells are constantly being generated to maintain the body’s defensive system, as with white blood cells, or its digestive systems, in the regeneration of the intestinal lining.

Unfortunately, no breed of dogs is spared by the virus’ reach, yet infections are most common amidst puppies, decreasing with age from a 91% mortality rate, to 10% in adult dogs.


One cannot neglect the danger posed by the parvovirus, dog owners even less so. Hence, any prevention which might help one avoid the heartbreak of losing their faithful companion, or just bypass the sight of their beloved dog suffering needlessly, should be taken.

Sick Boxer

Vaccination is the quick and inexpensive prevention. It is all you need to protect your dog and other dogs from such a cruel and vicious virus which modern medicine has luckily managed to confront.

Nevertheless, it is also the dog owner’s responsibility to make their dogs’ favourite places safe for all by immediately picking up faeces to reduce the risk of contamination and dispersion. Ultimately, prevention is easy as it only comes down to each owner’s awareness and discipline.

References With Thanks To –

  1. Nandi, S, and Manoj Kumar. “Canine Parvovirus: Current Perspective.” Indian Journal of Virology : an Official Organ of Indian Virological Society, Springer-Verlag, June 2010
  2. “Canine Parvovirus.” Cornell University College of Veterinary Medicine, 12 June 2019
  3. Brooks, Wendy. “Parvovirus in Dogs – Veterinary Partner.” VIN, 05 August 2018
  4. Nicholson, Lindsay B. “The Immune System.” Essays in Biochemistry, Portland Press Limited, 31 Oct. 2016
  5. Awad, Romane A, et al. “Epidemiology and Diagnosis of Feline Panleukopenia Virus in Egypt: Clinical and Molecular Diagnosis in Cats.” Veterinary World, Veterinary World, May 2018

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