Horse owners: there's an emails circulating claiming a young healthy thoroughbred horse died after being wormed with the Pfizer product Equimax. The writer claims a veterinarian told him the horse died because the Praziquantel in Equimax is too strong.
HWAC made a call out to contacts to verify the information, the responses follow.
Praziquantal is an INCREDIBLY safe drug. It is approved for use in humans. It is actually approved for use in pregnant and nursing dogs (not many drugs can make that claim). Numerous studies have been carried out at many times the label dosages in many species. I know of no scientific mechanism by which praziquantal would “burn a hole” in the small intestine. However, gastrointestinal ulcers are well know to occur spontaneously in horses.
This kind of email causes serious distress to horse owners and is unfair to the pharmaceutical companies that work very hard to bring good products to the market. If a drug does cause an adverse effect, there is a proper mechanism for reporting such to the Veterinary Drugs Directorate who will then investigate.
As for availability, Pfizer bought Wyeth, thus acquiring Quest (moxidectin) so they no longer are marketing their ivermectin product. That’s simply business.