by Christine Wilford
Source: Journal of the AVMA, Volume 200, Number 6, March 15, 1992
In the never-ending search for the perfect flea product, owners may try almost anything. Advertisements may imply that "natural" products are superior to - and safer than - those that are synthetic or man-made. However, natural products can be toxic, too.
Health food stores, pet shops, feed stores, grocery stores and some veterinary hospitals sell various flea repellents that contain an ingredient called pennyroyal oil, derived from the pennyroyal plant, sqauw mint or mosquito plant ( Mentha pulegium and Hedeoma pulegoides). The toxic ingredient, pulegon, is historically known for repelling fleas. Unfortunately, what appears as a "natural" way to repel fleas (which may be incorrectly interpreted as safer) can cause a dog's death.
Pennyroyal oil is extremely toxic to the liver of many animals, including humans. Symptoms of toxicity result within hours of application, beginning with listlessness, vomiting, diarrhea, and bleeding from the nose, mouth, and intestines. Exposure may possibly culminate with convulsions. Depending upon the amount of exposure, treatment may be futile, and death may ensue within one to two days.
Do not use pennyroyal oil in its pure form. And be cautious with shampoos, powders and any other form of flea product containing pennyroyal oil. Your best bet is to use only approved, reliable flea-products. Ask your veterinarian about new products or those that seem questionable.
Remember . . . natural does not necessarily mean safer or superior. After all, arsenic and cyanide are natural, too!
From the AKC GAZETTE, Veterinary News column, p. 34.