Thursday, September 29, 2011
647. Parvovirus still kills puppies and young dogs
Recently I had a chat with Vet 1 regarding the importance of evidence-based medicine in the diagnosis of vomiting and diarrhoea in puppies. There was presented a case of a puppy with vomiting and diarrhoea vaccinated 5 days ago. Vet 1 did not think it was parvovirus since the puppy had been vaccinated and the recent vaccination was 5 days ago.
Vet 1 showed me two comments about parvovirus infections in a short paragraph in veterinary medicine text book edited by US vets. These comments are:
1. Parvoviral tests will provide false positive if the puppy has been vaccinated from 5 - 10 days ago.
2. Most puppies with parvoviral infections survive when given supportive treatment.
POINT NO. 1
Apparently one Singapore vet had remarked to Vet 1 that parvovirus test will show a false positive when the puppy had been vaccinated 5 days ago. Therefore, Vet 1 showed me the book which stated the same. I said: "Will Vet 1 put in writing that he or she finds that a positive parvoviral test is a false positive? I doubt it. The puppy may have got vaccinated 5 days ago but it could be incubating the parvoviral infections before that and shows positive on the test. So, it can also be a true positive."
In any case, I got this puppy which was vaccinated 5 days ago but suffering from vomiting and diarrhoea tested for parvovirus. It was positive.
POINT NO. 2
"From my experience in working with the professional dog breeders in Pasir Ris for around 2-3 years, covering almost all the breeders, I know that parvovirus kills puppies despite supportive treatment," I said. "This observation has had been reported by various breeders and vets in countries like Australia.
"Much depends on the immune status and age of the puppies, the number of vaccinations, whether the dams have had been regularly vaccinated to produce maternal antibodies, the environmental load of parvoviruses and the strains. The author of the book cannot be trusted as he wrote a generalised statement. Young puppies with one or no vaccinations rarely survive even with supportive treatment because they are very young and their immune system is not developed. Breeders sometimes miss out regular vaccinations of their dams and it is extremely difficult for breeders to isolate infected puppies owing to their management system of cleaning crates with the same brushes."
IMAGE SHOWS A CASE OF PARVOVIRUS WHERE THE PUPPY WAS VACCINATED 5 DAYS AGO AND SOLD. A DIAGNOSIS OF PARVOVIRUS ON EVIDENCE-BASED MEDICINE NEEDS A BLOOD TEST, PARVOVIRAL TEST TO CONFIRM THE CLINICAL SIGNS OF VOMITING AND DIARRHOEA.
In rare cases, expensive supportive treatment like blood transfusion, intensive care, IV drips, antibodies, long hospitalisations may save the odd puppy. But how many owners are willing to pay for such treatments which are not guaranteed to save the puppy? The puppy costs $500 - $1,000. Do you really expect the owner to shell out much more to save it without a guarantee of success? There will be owners but not many.
Two years ago, one pet shop girl told me that her staff spent $20,000 to treat her puppy with vomiting and diarrhoea at a veterinary practice when I tested it to be positive for parvovirus. The staff took the puppy to another practice for treatment since I gave a poor prognosis. I had no reason to doubt her story although it does sound incredible.
In the past years, I used to go to pet shops to vaccinate puppies even if there were only 2-3 puppies and got to know more about the practices of the pet shops and breeders. But I have stopped doing it nowadays as I need to spend more time with my private patients to build up the practice rather than being "not around" when I went to the pet shops and breeders.
Despite advances of the world's technologies, parvoviruses still kill puppies in 2011 and in some cases, young dogs that have not been vaccinated properly or not vaccinated.