Adverse Reactions in Cats From Frontline Topical

Merial's Frontline topical flea and tick control product contains the active ingredient Fipronil, an insecticide which may cause mild to severe reactions in cats. Some effects, after even one-time use, have included skin reactions, neurological damage, and in some cases, death. Having previously used Frontline Topical on your cat is also no guarantee that adverse side effects will not occur.

  1. What is Fipronil

    • Fipronil is an insecticide that has been registered for use by the EPA in the U.S. since 1996. It is used to ward off fleas, ticks and other insects

    How Does Fipronil Work

    • Fipronil stops regular nerve function by blocking gamma-aminobutyric acid receptors in the central nervous system. This GABA receptor neural system helps prevent over-stimulation of the nerves by blocking some neural activity. When Frontline containing Fipronil is applied topically to your cat, it is stored under your cat's skin in the oil glands. This makes Frontline waterproof as it continuously releases the Fipronil through your cat's hair follicles.

    Common Adverse Reactions in Cats

    • Common adverse reactions in cats from Frontline containing Fipronil, are chemical burns to the site where the topical was applied, hair loss, lethargy, behaviors such as running in circles, hiding, agitation, crying and excessive grooming.

    Moderate Adverse Reactions in Cats

    • Moderate adverse reactions in cats can include tremors, impaired gait, gastrointestinal upset, excessive thirst, foaming at the mouth, coughing and gagging. Some cats have experienced unsteady gait, ulcerations, and loss of appetite.

    Severe Adverse Reactions in Cats

    • Severe adverse reactions can include respiratory problems, kidney enlargement and failure, thyroid problems, seizures and lower kitten litter sizes and weights and higher fetus mortality. In some instances, death has occurred to adult cats receiving Frontline Topical.