Hartz UltraGuard topical liquid products for cats all contain the active ingredient etofenprox. Etofenprox is classified as a synthetic non-ester pyrethroid that is effective against fleas and ticks.

At EPA's insistence, Hartz Mountain Corp. has agreed to cancel uses of several flea and tick products that may be associated with a range of adverse reactions, including hair loss, salivation, tremors ...

Gail Rankin of Washington County, Tennessee, worries a popular over-the-counter flea and tick product could harm or even kill your pet. She says her cat nearly died from Hartz flea and tick drops last ...