Canine Parvo Virus

Canine Parvo Virus

Also known as “CATFLU in Dogs”, “KATGRIP” or “PARVO”, it brings dread to any young puppy owner.

This article has been written to shed some light on the disease and try and dispel some of the myths and old wives’ tales.

The Canine Parvo Virus, that causes this disease, started out in the cat and mutated and transferred to the dog. That is why this disease is often called “Catflu” or “KatGrip” even though it has nothing to do with the cat anymore! It is now a different virus to the original cat virus (Feline Parvo Virus). This virus attacks the fast growing cells of the body, mainly the gut lining but also rarely the heart (myocarditis) and brain (encephalitis) – these last two cases are usually fatal. This is a very contagious disease that spreads quickly through a litter of puppies. During the initial stage where there are no signs of sickness yet, the puppies share the virus amongst themselves as they are in contact with each others faeces.

The Parvo virus is very small but very sturdy. It is highly resistant to heat and most common disinfectants, so can hang around in the environment (your home, the park or the street – in fact the whole world is full of the virus) for a very long time – even up to a year long. It is best to clean all the surfaces in your home, that your puppy had contact with, with household bleach – especially where the puppy may have left any diarrhoea. Wash your hands before and after handling your puppy. So if this virus is everywhere, why are adult dogs ok and puppies not?

Adult dogs have stronger immune systems to fight off a viral attack and their vaccinations have built up a good immunity to protect them from the virus.

Puppies on the other hand have many things that actually “help” the virus for example:

1) Puppies have very fast dividing cells in their gut lining. This makes a perfect place for the virus to grow. A puppy’s immune system is still learning about the bad guys called viruses and can not protect the body from a viral attack yet. In other words the immune system is naïve to threats at this point.

2) The stress of a change of environment when going to a new home with a change of food can increase a puppy’s susceptibility to disease, letting the Parvo virus in the door easier. Try and use the same food as your puppy’s breeder used for a week or too. This will help with nutrition health during the settling in process. Your puppy will eat better and therefore be stronger.

3) Other diseases that can occur at the same time (Distemper, worms or a bacterial infection), help the Parvo virus to attack the puppy’s gut. A worm infestation causes damage to the gut lining making it easier for the Parvo virus to get into and grow in the gut lining. Remember that even when you don’t see worms in a puppy’s poo, that puppy can still be infested. Puppies need to be dewormed from 2 weeks of age, every 2 weeks until 3 months old to prevent such an infestation.

4) Genetic factors include the increased incidence of Parvo in puppies with a black & tan coat colour (Rottweilers & Min Pins) and black coated Labrador Retrievers. The course of the disease is also often much more severe in these breeds.

How the puppy gets sick:

Puppies are infected by sniffing/licking a surface or object that already has Parvo virus on it. So wash your hands after handling your other dogs or doing poo patrol. The virus enters the body through the lining of the nose and/mouth and lodge in the closest lymph nodes. It then moves around the body for 4-7 days. This is called the incubation period. The virus multiplies in the lymphnodes and enters into the blood, and returns to the gut and settles in the gut lining. The virus causes the lining to die off, so that the puppy can’t absorb any food or liquid, causing weight loss and diarrhoea – often with blood in it.

The main signs of Parvo virus infection are:

– Listless/ no energy

— Fever

— Not eating/anorexia

— Vomiting and Diarrhoea

— Weakness

— Dehydration

Treatment varies from vet to vet, but the main focus is to support your puppy’s body until it can expel the virus and heal the gut. This can take anywhere between 3 to 10 days, the average hospitalisation time being about 5 days. Remember every case is unique and can differ from what is described here.

The main treatment protocols include:

1. A drip/electrolytes to give fluids and medication straight in the puppy’s vein and rest the gut. This also prevents all the medication from being vomited out and not being used by the body.

2. Antibiotics, to prevent secondary bacterial infection from the environment and from the gut itself.

3. Painkillers and anti-nausea medication

4) Force feeding to help the gut lining stay functional and repair. Prevention is primarily based on VACCINATION. A Puppy needs it’s first vaccination at 6 weeks and boosters 4, 8 and 12 weeks thereafter. An annual booster is very necessary. To be even safer, the mother of the puppies should have been vaccinated just before she was mated – or have continuously up-to-date vaccinations to give the puppies a better chance of protection. This is not something that you as a puppy owner can control, but it never hurts to ask.

The two main reasons for a perfectly good vaccination not giving protection are:

1. Maternal antibodies interfere with the puppy’s own immune response to the vaccine. The protection that a puppy receives from it’s mother – through her milk – fights against the vaccine and uses it up leaving no vaccine particles over to prime the puppy’s own immune system.

2. We can only safely vaccinate puppies at 6 weeks old and puppies can become susceptible to a Parvo viral infection from as early 3 weeks old. This window is where the virus can infect a puppy when it is not protected in any way.

So, in summary, know where your puppy comes from, decrease environmental stress and viral challenge and VACCINATE and deworm your pets regularly. Enjoy your new puppy. “Disclaimer: Please remember that these notes are to help with understanding and explaining a certain topic. If you have any concerns over the health of your pet, please consult your veterinarian immediately – Thanks”

REFERENCES: Textbook of Veterinary Internal Medicine; ETTINGER et al (1995) Pg 403,405-409,624,1012-1013,1202-1203,1909-1910. Viral Diseases BVSc IV Class Notes, Dept Tropical Diseases UP 1998


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