Dr Liesel van der Merwe is a small animal medicine specialist. Send her your questions: This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Dr Liesel van der Merwe

Summer brings Parvoviral diarrhoea and vomiting. Don’t know why. The virus is extremely resistant to the environment and dogs breed throughout the year – not just in summer – so puppies are a year-round phenomenon. Yet we get massive Parvoviral outbreaks in summer.

I am seeing it at Onderstepoort and I’m hearing from all vets in Pretoria that there is a huge increase in the number of puppies with severe diarrhoea and vomiting, which is eventually diagnosed as canine parvovirus.

Please take note of the following regarding vaccination: Dogs and cats are born without any antibodies. There is no blood crossing the placenta. Within the first 24 hours the lining of the intestine is not ‘complete’ and allows the body to absorb large proteins, such as antibodies. After that initial window period, all proteins are digested and broken down.

It is thus essential that puppies and kittens suckle in the first day to absorb the rich colostrum milk, which contains high levels of antibodies. This gives then maternal immunity and they are thus protected against all the viruses and infections the dam is immune to or vaccinated against.

Antibodies do not live forever. The body breaks them down over several weeks and more are made as the immune system is stimulated. Puppies start losing their maternal immunity from six to eight weeks. It varies between individual puppies in a litter. We start vaccinating dogs at six weeks old to try to start stimulating immunity as early as possible.

In some cases – where the maternal immunity is dropping – the vaccination will work. In other cases – where there is still some maternal immunity – those antibodies will block the vaccine and it will not work. This is why boosters at the proper time are so essential.

The repeat vaccination three weeks later will work on puppies which blocked the vaccination at six weeks. The final booster three weeks later will boost that vaccination.

A vaccination isn’t effective unless it is boosted at that three to four week period. Otherwise the immunity slips out of the body and is forgotten. Once the booster is given, at the right time, the memory is more fixed. Some diseases need yearly booster vaccinations, others less often as the immunity is longer lived.

Vaccines also will not ‘take’ if the puppy is stressed with other disease, malnourished or has a heavy worm infection. For a puppy to be properly vaccinated we mean: Three vaccines, three weeks apart, starting at six to eight weeks of age.

You are wasting your money and living under a false sense of security if you just accept the breeder’s vaccination history. If you have a properly vaccinated puppy, some may still become infected with parvo, but it is highly unlikely. Once your dog is adult, the risk is extremely unlikely.

Puppies in the six to ten week gap will be vulnerable to infection – even if they are vaccinated – as the immunity hasn’t had time to properly develop yet. These pets must be kept in a safe environment away from other animals with unknown vaccination status.

When vaccinating older dogs for the first time, they only need the primary injection and then the booster three to four weeks later, as they do not have any circulating maternal antibodies to interfere with the vaccination.

With cats, the scenario is different, as it always is with cats. They only generally need two vaccinations as kittens, and not three, as we start later with their vaccinations when no maternal antibodies are present. This is because they do not have vaccine-preventable early childhood fatal diseases, such as parvo in dogs. Kittens are susceptible to snuffles and this vaccination is like the flu vaccination – not 100% effective and with a short duration effect. It needs yearly repeating.

Before you worry about the toys and cute collars and blankets, make sure you have addressed your new puppy or kitten’s health issues. Vaccination at the right time, boosters, proper nutrition and regular deworming are essential to a young dog and cat. Then there is the important socialising, which needs to happen before four months of age.

Vets have to deal with sick puppy after sick puppy, all with a relatively preventable disease, requiring intensive treatment, which many owners cannot manage. It’s distressing for all parties involved, so plan ahead.