The New York Times reports the Environmental Protection Agency is intensifying its scrutiny of liquid flea and tick treatments for dogs and cats, warning pet owners that the treatments may have possibly fatal side effects.

The treatments are applied topically, usually between the animal’s shoulder blades. There have been no recalls of the products, and the agency said in May that there is no reason to avoid them, the Times reported.

The E.P.A. is investigating a large number of anecdotal reports involving both cats and dogs who received spot-on treatments and suffered problems like skin irritations, hair loss and tremors, according to agency spokesman Dale Kemery.

The agency now is evaluating all available data on the pesticides, including reports of adverse reactions, the clarity of the directions and label warnings, and the pre-market safety data submitted in support of the products, the paper reports.

In the meantime, Mr. Kemery told the Times that pet owners should read the directions on any veterinary medicine they use. “Don’t use dog products on cats and vice versa,” he added. “If you detect negative reactions, the vet is the first stop.”

Photo of fluffy dog and kitten courtesy of Flora's photostream on Flickr.