Q: The May 2006 issue of CAT FANCY issued a warning on page 29 concerning the use of permethrin in flea and tick control. The warning advised keeping cats away from dogs until the application dries. Since most lawn and insect control fertilizers use permethrin as their active ingredient, what precautions should I take when using these products?
A: According to my friend and colleague Dr. Jill Richardson, director of consumer relations and technical services for Hartz and consulting editor for toxicology on the Veterinary Information Network, permethrin (which is an insecticide, not a fertilizer) is sometimes used to treat lawns, although the concentrations that are used are very low. Your cat is unlikely to be harmed by the permethrin that is sprayed on your lawn. Problems are seen when there is exposure to the super-concentrated form found in some preparations of flea control products for dogs. But Dr. Richardson still recommends that you check with the product manufacturer regarding the use of lawn care products around your pets. Most of the time, you only need to keep the pet out of the area while the product is applied, and until it dries. But always check with the manufacturer, to be safe.
Arnold Plotnick, DVM