If your cat licked Revolution Plus, the most likely outcome is drooling, foaming at the mouth, and possibly some nausea or vomiting. This happens because the product tastes extremely bitter, not because your cat is being poisoned. In most cases, these symptoms resolve on their own within a short time, but there are a few things you should do right away and some warning signs to watch for.
Why Cats Drool and Foam After Licking
Revolution Plus contains two active ingredients, selamectin and sarolaner, suspended in a liquid base that has a very bitter taste. When a cat licks the wet product off the application site (or off another cat in the household), that bitterness triggers an intense gustatory reaction: heavy drooling, foaming at the mouth, and sometimes gagging or vomiting. It looks alarming, but this is a taste response, not a sign of systemic poisoning.
The foaming can be dramatic. Some owners describe it as their cat looking like they ate soap. This is normal for bitter substances and usually stops within 15 to 30 minutes once the taste clears.
What to Do Right Now
Offer your cat something tasty to eat or drink. Wet cat food, tuna, or tuna juice works well to wash the bitter taste out of the mouth and settle nausea. You can also gently flush your cat’s mouth with room-temperature water using a syringe (no needle) if your cat will tolerate it. The goal is simply to dilute and replace the bitter taste so the drooling stops faster.
If the product is still wet on the application site, keep your cat from licking more of it. For multi-cat households, separate the treated cat from other cats until the product has fully dried, which typically takes about 30 minutes.
When It Becomes More Serious
Sarolaner, one of the two active ingredients in Revolution Plus, belongs to a drug class called isoxazolines. The FDA has issued a safety communication noting that isoxazoline products can, in rare cases, cause neurological side effects in cats and dogs. These include muscle tremors, loss of coordination, and seizures.
The key distinction is between a taste reaction and a neurological reaction. Drooling and brief vomiting that resolves within an hour is a taste reaction. Tremors, wobbliness, twitching, or seizure-like activity is something different entirely, and your cat needs emergency veterinary care if any of these appear. These neurological events are uncommon, but they’re the reason to keep watching your cat for several hours after a licking incident rather than assuming everything is fine once the drooling stops.
Signs That Need Veterinary Attention
- Muscle tremors or twitching that don’t stop on their own
- Loss of coordination or stumbling
- Seizures of any kind
- Vomiting that continues beyond the first hour
- Unusual agitation or hyperactivity that seems out of character
If you see any of these, contact your veterinarian or call the Pet Poison Helpline at (855) 764-7661. If your cat is actively seizing or tremoring, go directly to an emergency vet clinic.
How Much Is Too Much?
A cat licking a small amount of Revolution Plus off the application site is not the same as ingesting a full dose orally. The amount a cat typically gets from grooming the spot is a fraction of the applied volume, especially if the product has already started to absorb into the skin. This is why most licking incidents produce nothing worse than temporary drooling.
That said, the risk goes up if your cat managed to lick the tube directly, if a second cat groomed a freshly treated cat before the product dried, or if the product was applied somewhere the cat can easily reach (like the shoulder blades rather than the base of the skull). The more product ingested, the greater the chance of gastrointestinal upset beyond simple drooling.
Preventing It Next Time
Revolution Plus is designed to be applied at the base of the cat’s neck, right at the skull line, where a cat physically cannot reach with its tongue. Part the fur until you can see skin, then apply the liquid directly to the skin in that spot. If you’ve been applying it lower on the back or between the shoulder blades, your cat may be flexible enough to reach it.
In multi-cat homes, separate cats for at least 30 minutes after application so they can’t groom each other. Some owners find it easiest to apply the treatment right before feeding time, so each cat is distracted by food while the product dries. Once Revolution Plus is fully absorbed and the fur is dry, licking the area is no longer a concern.