# What If My Cat Licks NexGard? Safety and Risks Is it safe for cats to lick NexGard? No. NexGard is a flea and tick medicine made for dogs, and the ingredients can poison a cat that swallows them. If your cat licked NexGard, treat it as a possible poisoning and call your veterinarian or a pet poison hotline right away. This article is educational and is not a substitute for veterinary diagnosis or treatment. ## Quick Answer - NexGard is not approved for cats. It is a dog product, and cats should never be given it or allowed to lick it. - A cat can lick NexGard off a dog's coat, off a treated surface, or from a dropped or chewed tablet. - Signs of poisoning can include vomiting, drooling, wobbliness, tremors, and seizures. Some cats show no signs at first. - Call your veterinarian, an emergency clinic, or a pet poison hotline immediately. Do not wait for symptoms to appear. - Do not try to make your cat vomit unless a veterinarian tells you to. ## What Is NexGard and What Is It Used For? NexGard is a brand name for medicines in the isoxazoline class. The chewable tablet form contains afoxolaner and is labeled for dogs. It is used to kill fleas and ticks and to treat certain mite infestations. One field study in dogs found that afoxolaner was effective against a chewing louse that infests dogs [1]. Another report described successful treatment of a severe mange mite infestation in a pet guinea pig with oral afoxolaner [2]. There is also a topical product called NexGard Combo. It contains three active ingredients: esafoxolaner, eprinomectin, and praziquantel. This product is used in cats in some countries. Studies show it can treat certain parasites in cats, including a nasal worm and a fur mite [3][4]. The important point for you as a cat owner in the United States is this: the chewable NexGard tablet is a dog product. Even the topical cat version is prescription-only and must be applied by you exactly as your veterinarian directs. A cat should never lick either form. ## How Does NexGard Work? Afoxolaner and esafoxolaner belong to the isoxazoline family. These drugs overstimulate the nervous system of fleas, ticks, and mites, which kills the parasites. At the correct dose in the correct species, the drug is generally well tolerated. Eprinomectin is a macrocyclic lactone. This drug class kills parasites too, but it can affect the nervous system of the animal that takes it. Some cats have a genetic change that makes them unable to clear these drugs from the brain. A case report described a young Maine Coon cat that developed tongue protrusion, dilated pupils, weakness, and wobbliness after a routine application of an eprinomectin-containing product at the labeled dose. Testing showed the cat had a non-functional drug transporter called P-glycoprotein, which raised the risk of nerve toxicity [5]. That case involved a product applied at the correct dose to a cat. It shows that even proper use can cause problems in a cat with this genetic variant. When a cat licks a dog product, the exposure is uncontrolled, and the risk is higher. ## Dosing Basics for Cats ### Who decides the dose? Your veterinarian does. There is no safe home dose of dog NexGard for a cat. Your veterinarian calculates any cat-approved parasite medicine from your cat's weight, age, health status, and the parasites you need to control. Never split a dog chew and give part of it to a cat. ### How is it given? Cat-approved topical products are applied to the skin at the back of the neck, in a spot the cat cannot easily lick. Dog chewable tablets are given by mouth to dogs. These are different products with different ingredients and different dosing. ### What if you miss a dose? If your cat is on a prescription parasite preventive and you miss a dose, call your veterinarian's office for instructions. Do not double up to catch up. If you are not sure whether your cat is due, check the label or call the clinic. ### What if your cat licks a treated dog? This is the most common real-world exposure. A cat that grooms a dog shortly after the dog's dose can swallow some of the medicine. If this happens, call your veterinarian or a poison hotline and give them your cat's weight, the product name, and the time of exposure. ## Common and Serious Side Effects | Side effect | How common or serious | What to do | |---|---|---| | Vomiting, drooling, poor appetite | Common with mild ingestion, can be the first sign of poisoning | Call your veterinarian or a poison hotline now | | Wobbliness, weakness, unsteady walking | Serious, seen in a reported cat case after a labeled dose of an eprinomectin product [5] | Go to a veterinarian the same day | | Dilated pupils, tongue protrusion | Serious, reported in the same cat case [5] | Treat as an emergency | | Tremors, seizures, collapse | Life-threatening | Go to an emergency clinic immediately | | Itching, hair loss, scaling at the application site | Reported in cats with mite infestation in a field study [4] | Tell your veterinarian, this may need a routine visit | | Stomach upset after licking a household poison | Common with products like boric acid roach bait [6] | Call a poison hotline for guidance | Some cats show no signs for hours after licking NexGard. That does not mean they are safe. Signs can appear later, so a call to a professional is the right first step even if your cat seems fine. If your cat has a habit of licking odd surfaces or objects, that behavior can have many causes. Our guide on [cat licking walls or floors](/knowledge/veterinary-medicine/anxiety-and-behavior-support/cat-licking-walls-floors-pica-medical) explains when it points to a medical problem. ## Is It Safe for Cats to Lick NexGard Combo? The topical NexGard Combo product is used in cats in some countries, and studies support its use against certain parasites when it is applied as directed [3][4]. That does not make it safe for a cat to lick. The label directions exist for a reason. The product goes on the skin at the back of the neck so the cat cannot reach it. If your cat licks the application site, or licks another cat that was just treated, the drug can be swallowed. Eprinomectin is the ingredient of most concern, because swallowing it raises the risk of nerve signs, especially in cats with the P-glycoprotein variant described in the case report [5]. If your cat licked NexGard Combo, call your veterinarian or a pet poison hotline and tell them the product name, your cat's weight, and how long ago it happened. Do not wash the area with harsh products unless a veterinarian tells you to. ## Who Should Not Take It and What Interacts With It Cats with a known sensitivity to isoxazolines or macrocyclic lactones should not receive these drugs. Cats with the ABCB1 gene variant that causes P-glycoprotein deficiency are at higher risk of nerve toxicity from macrocyclic lactones like eprinomectin [5]. Your veterinarian can discuss testing if you have a breed or family history that raises concern. Drug interactions matter too. Any medicine that affects the same drug transporters or the nervous system can change the risk. Tell your veterinarian about every product your cat takes, including prescription drugs, over-the-counter products, and supplements. Never give a dog product to a cat, and never let a cat groom a dog that was just treated until the product has dried and your veterinarian says it is safe. If your cat eats things it should not, including human foods, our article on [uncooked hot dogs](/knowledge/veterinary-medicine/clinical-methods/can-cats-eat-uncooked-hot-dogs) covers another common household risk. ## Overdose and When to Call a Veterinarian or Poison Control Call for help right away if your cat licked NexGard, ate a NexGard chew, or groomed a dog that was recently treated. Have these facts ready: your cat's weight, the product name and strength, the amount you think was swallowed, and the time it happened. Call your veterinarian or an emergency clinic first. You can also contact a pet poison hotline. Do not induce vomiting unless a veterinarian tells you to, because some poisonings get worse if the cat vomits. Treatment depends on the signs. A cat with mild stomach upset may need monitoring and supportive care. A cat with tremors, seizures, or weakness needs emergency care, and the cat in the published case recovered over about 3 months with conservative management [5]. That timeline shows why early veterinary care matters. If your cat licked a household pesticide instead, the advice is similar. Boric acid roach bait most often causes stomach upset when cats ingest it [6]. Call a professional for guidance either way. ## Limitations and When to Contact a Veterinarian This article cannot tell you whether your specific cat is poisoned. Only a veterinarian who examines your cat can do that. Individual cases need a veterinarian, and the timing of care can change the outcome. Contact a veterinarian the same day if your cat licked NexGard or a treated dog, even if your cat seems normal. Go to an emergency clinic now if you see tremors, seizures, collapse, severe weakness, trouble breathing, or a cat that cannot stand or walk normally. Schedule a routine visit if you have questions about parasite prevention, if your cat has skin irritation at an application site, or if you want to switch products safely. ## Frequently Asked Questions ### Can a cat get sick from licking a dog that just had NexGard? Yes, a cat can get sick this way. The cat swallows some of the medicine while grooming, and the dose is not controlled. Call your veterinarian or a poison hotline and describe the product and timing. ### How long after licking NexGard would signs show up? Signs can appear within hours, but the exact timing varies with the amount swallowed and the cat's sensitivity. Some cats show no signs at first and develop problems later. Do not wait for symptoms before calling for advice. ### Is NexGard Combo safe for cats if it is made for cats? It is safe only when applied exactly as your veterinarian directs, in the spot your cat cannot lick. Licking the product changes how much drug is swallowed and raises the risk of nerve signs. Treat any licking as an exposure and call for guidance. ### Can I just watch my cat at home instead of calling? No, watching alone is not enough. Poisoning can progress quickly, and early treatment is easier than treating a cat in a crisis. A phone call costs little and can tell you whether your cat needs to be seen. ### Are some cats more sensitive to these medicines? Yes. Cats with a specific ABCB1 gene variant have non-functional P-glycoprotein and a higher risk of nerve toxicity from macrocyclic lactones like eprinomectin [5]. Your veterinarian can help you decide whether testing or a different product makes sense for your cat. ## Related Articles - [Can Cats Eat Catnip? Nepetalactone and Safe Use Guide](/knowledge/veterinary-medicine/toxicology-food-safety/can-cats-eat-catnip-nepetalactone-and-safe-use-guide) - [Can Cats Eat Uncooked Hot Dogs? Risks and Safer Options](/knowledge/veterinary-medicine/clinical-methods/can-cats-eat-uncooked-hot-dogs) - [Cat Licking Walls or Floors: Pica or Medical Issue?](/knowledge/veterinary-medicine/anxiety-and-behavior-support/cat-licking-walls-floors-pica-medical) - [Are Jelly Cats Safe for Pets? A Complete Safety Guide](/knowledge/veterinary-medicine/behavior/jelly-cats-pet-toys) - [Nexgard Flea Treatment For Dogs](/knowledge/veterinary-medicine/parasitic-diseases/nexgard-flea-treatment-for-dogs) - [Can Cats Eat Spirulina? Heavy Metal and Algae Safety](/knowledge/veterinary-medicine/toxicology-food-safety/can-cats-eat-spirulina-heavy-metal-and-algae-safety) - [Cat Licked Flea Medicine: What to Do Right Now](/knowledge/veterinary-medicine/toxicology-and-food-safety/cat-licked-flea-medicine-what-to-do) - [Nexgard for Cats: Side Effects and Allergic Reactions](/knowledge/veterinary-medicine/pet-medication-guide/nexgard-cats-side-effects-allergic-reactions) - [Is Revolution Safe If My Cat Licks It?](/knowledge/veterinary-medicine/pet-medication-guide/cat-licks-revolution-safety) ## References 1. [Efficacy of afoxolaner (NexGard®) against natural infestations with Trichodectes canis in dogs under field conditions](https://pubmed.ncbi.nlm.nih.gov/36071527/). Parasites & vectors, 2022. 2. [Effective treatment with afoxolaner (NexGard) of Trixacarus caviae in a pet guinea pig](https://pubmed.ncbi.nlm.nih.gov/39239737/). Veterinary medicine and science, 2024. 3. [Efficacy of NexGard® combo (esafoxolaner-eprinomectin-praziquantel) against natural Mammomonogamus ierei infection in cats](https://pubmed.ncbi.nlm.nih.gov/42034956/). Veterinary parasitology, regional studies and reports, 2026. 4. [Pilot field study to assess efficacy of NexGard Combo®, a topical combination of esafoxolaner + eprinomectin + praziquantel, against natural Lynxacarus radovskyi infestation in cats](https://pubmed.ncbi.nlm.nih.gov/42735466/). Veterinary parasitology, 2026. 5. [Inherent P-glycoprotein deficiency and macrocyclic lactone toxicity in an Australian Maine Coon cat homozygous for ABCB11930_1931del TC](https://pubmed.ncbi.nlm.nih.gov/41694419/). JFMS open reports, 2026. 6. [My Cat Licked Roach Poison, What Happens Now?](https://www.petpoisonhelpline.com/uncategorized/my-cat-licked-roach-poison-what-happens-now/). Pet Poison Helpline. ## Further Reading - [My Cat Ate Neosporin Will They Be (Pet Poison Helpline)](https://www.petpoisonhelpline.com/uncategorized/my-cat-ate-neosporin-will-they-be-okay/) - [American Veterinary Medical Association: First Aid Tips for Pet Owners](https://www.avma.org/resources-tools/pet-owners/emergencycare/first-aid-tips-pet-owners) - [Merck Veterinary Manual: Cat Owners](https://www.merckvetmanual.com/cat-owners)