What Are the Warning Signs a Cat Has Licked Frontline?

A few licks of Frontline usually causes only major drooling.
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The recommended application spot for Frontline is a place where the cat cannot lick, such as the base of the back of the head. Unfortunately, with almost otherworldly contortion abilities, she may reach it anyway. If your cat manages to ingest the medication, the side effects are usually mild.

Drooly Kitty

Cats are compulsive groomers, and if your cat feels something wet on her fur, she will lick it. She just can't help herself. Luckily, the main active ingredient in Frontline is fipronil, which is not lethal if ingested. The medication's taste usually causes the most notable reaction, as the cat's mouth waters to get rid of the foul flavor. She'll drool excessively, like foaming-at-the-mouth type of waterfall drool. There's little you can do except offer her plenty of water to help her stay hydrated and to wash the taste from her mouth. She'll eventually rid herself of the taste and return to normal.

More Severe Symptoms

Don't assume that the worst your cat will suffer is drooling like a Saint Bernard for a while after licking Frontline. As with any medication, exceptions, drug interactions and more severe side effects can occur. Depending on your cat's medical or genetic history, she may develop more severe reactions from her experimental taste, such as vomiting, lethargy or tremors. Her appetite may change and she may not seem like herself. If her behavior changes dramatically after her exposure to Frontline, contact your veterinarian immediately for advice and guidance.

Skin Reactions

Just because your cat can't reach the Frontline with her tongue doesn't mean the medication can't cause her some discomfort. Some cats develop physical reactions to the ingredients in the medication, resulting in hair loss, skin irritation and an intense itch. This skin irritation may extend to her mouth after licking, causing her ulcers and pain on the sensitive skin inside. She may cry out and go crazy trying to scratch at the spot you treated, or shake constantly in an attempt to get rid of the wet feeling. This may calm down once the medication dries completely, but some cats are so sensitive to the chemicals they require medical treatment. Call your vet for advice if your cat seems to be in pain or physical discomfort from the medication.

Treatment & Prevention

The level of treatment your cat needs depends on the intensity of side effects she's experiencing. If she's simply drooling like Niagara Falls but otherwise seems fine, offer her water or tuna to help her dilute the stuff and moderate the taste in her mouth. More severe behavioral changes require an expert's care, so call your vet as soon as you notice things that concern you. In some cases your cat may need an allergy shot to counteract an allergic reaction to the medication, but in more severe situations she may require hospitalization to flush toxins from her system and stabilize her. Adverse reactions to Frontline typically show fairly quickly, so keep an eye on your cat for the first days after applying the medication. The sooner she receives care, the more likely she'll recover from any side effects. Prevent the possibility of illness by keeping her mouth away from the Frontline until it dries completely. Apply it in a hard-to-reach place, such as on the back of her head, and keep her occupied after application to let it dry without interference. If she's intent on reaching for it, use an Elizabethan collar -- also known as the Cone of Shame -- to block her efforts.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

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