# Simparica for Cats: What It Covers and How It Works Simparica for cats is a common search, but the truth is that the chewable Simparica and Simparica Trio products sold in the United States are approved for dogs, not cats. The same drug family, the isoxazolines, does appear in cat products, but under different brand names and in topical form. This article explains what actually exists for cats, what each product covers, and how your veterinarian decides what your cat needs. This article is educational and is not a substitute for veterinary diagnosis or treatment. ## Quick Answer - Simparica and Simparica Trio chewable tablets are labeled for dogs in the U.S. Do not give a dog chewable to your cat. - The sarolaner in Simparica is the same drug class found in Revolution Plus, a topical cat product that combines selamectin and sarolaner [1]. - Revolution Plus is applied as a low-volume spot-on once a month and covers fleas, several tick species, heartworm, roundworms, and hookworms [1]. - Your veterinarian calculates the correct dose from your cat's weight and health status. Never split or guess at a dose. - If you want a sarolaner-based preventive for your cat, ask your vet about Revolution Plus or another feline-labeled option. ## What Simparica Is and What Veterinarians Actually Use It For Simparica is the brand name for sarolaner, a chewable tablet in the isoxazoline class. Simparica Trio adds moxidectin and pyrantel to sarolaner in a single chewable tablet [2]. Both of these chewable products are approved for dogs. The published efficacy work on these chewables has been done in dogs, including studies against the Asian longhorned tick [2]. So when you search for simparica for cats, you are usually looking for one of two things. You may want to know whether you can use your dog's Simparica on your cat, and the answer is no. Or you may want a sarolaner product that is actually made for cats, and that product exists under a different name. Sarolaner is combined with selamectin in a topical product sold as Revolution Plus in the United States and as Stronghold Plus in the European Union [1]. This is the closest thing to a simparica equivalent for cats. It is a spot-on, not a tablet, and it is dosed for cats specifically. Veterinarians use these products for routine parasite prevention. That means stopping fleas before they start a household infestation, blocking ticks before they can transmit disease, and preventing heartworm and intestinal worms. If you want the big picture on routine prevention, see [Preventive Care For Cats](/knowledge/veterinary-medicine/preventive-care/preventive-care-for-cats). ## How It Works Sarolaner belongs to the isoxazoline class. These drugs act on the nervous system of fleas, ticks, and mites. They bind to receptors that are important in insect and arachnid nerve signaling, which causes uncontrolled nerve activity and death of the parasite. Mammals are much less sensitive to this effect at labeled doses, which is why the drug can be given safely when used as directed. In the cat topical product, sarolaner is paired with selamectin. Selamectin is a different class of drug with a different way of killing parasites. The two ingredients work together, which is why the combination gives both high efficacy and a fast speed of kill against fleas [1]. That fast kill matters because it reduces flea egg production, lowers the risk of flea allergic dermatitis, and reduces the chance of tapeworm infection from swallowed fleas [1]. The tick coverage is broad. A single treatment has shown efficacy above 90% for at least four weeks against ten tick species, including the lone star tick, the American dog tick, the black-legged tick, and the brown dog tick [1]. Killing ticks quickly also lowers the chance that a tick can pass along a disease organism. In one study, the selamectin and sarolaner combination protected cats against transmission of Borrelia burgdorferi, the bacterium that causes Lyme disease, from infected black-legged ticks [3]. ## Dosing Basics for Cats ### Who decides the dose Your veterinarian does. The dose depends on your cat's body weight, age, health conditions, and other medications. The labeled minimum dose for the cat topical combination is 6.0 mg/kg of selamectin plus 1.0 mg/kg of sarolaner, given once a month [1]. That number tells you how the product was designed, not what to measure at home. Products come in pre-filled applicators sized to weight ranges, and your vet picks the right one. ### How it is given The cat product is a topical spot-on. You part the fur at the back of the neck, between the shoulder blades, and place the liquid directly on the skin. Do not rub it in, and keep your cat from grooming that spot until it dries. Cats are often easier to treat with a spot-on than with a pill, and owner surveys show that ease of application and product attributes matter a great deal to cat owners when they choose a preventive [4]. ### What about a missed dose Give the next dose as soon as you remember if it is only a few days late. If it has been weeks, call your veterinarian for guidance. Do not double up to catch up. Monthly products work best when the interval stays close to 30 days, because protection against some parasites fades between doses. ### What about the chewable tablets Simparica and Simparica Trio chewables are for dogs. There is no feline-labeled chewable version of these products in the U.S. If your cat will not tolerate a spot-on, ask your veterinarian about other feline options, including flavored chews made for cats. ## Side Effects Most cats tolerate topical parasite preventives well. In controlled studies of the selamectin and sarolaner combination, no treatment-related adverse reactions occurred [5]. That is reassuring, but it does not mean reactions never happen in real-world use. Here is what to watch for. | Side effect | How common or serious | What to do | |---|---|---| | Brief drooling, lip smacking, or foaming after application | Uncommon, mild, often from tasting the product | Wipe the mouth, offer water, watch for 30 minutes | | Temporary greasy or matted fur at the application site | Common, cosmetic | Do not bathe for at least 24 hours, it will settle | | Mild redness, itching, or hair loss at the spot | Uncommon, usually mild | Note it, call your vet if it spreads or worsens | | Vomiting, diarrhea, or decreased appetite | Uncommon | Call your vet if it lasts more than a day | | Lethargy, wobbliness, tremors, or seizures | Rare but serious | Stop the product and call your vet right away | | Facial swelling, hives, trouble breathing | Rare, emergency | Go to a veterinary emergency clinic now | Neurologic signs are the main serious concern with isoxazoline drugs. They are uncommon at labeled doses, but they are the reason these products are used with extra caution in cats with a history of seizures. If you see any of these signs, treat it as urgent. ## Who Should Not Take It and Drug Interactions Do not use a dog chewable on a cat, at any dose. The chewables are formulated and flavored for dogs, and the tablet sizes do not match feline weight ranges. Talk to your veterinarian before starting a sarolaner product if your cat: - Is younger than the minimum age on the label or under the minimum weight for the product - Has a history of seizures or other neurologic disease - Is pregnant, nursing, or intended for breeding - Is sick, losing weight, or recovering from surgery - Is already taking another flea, tick, or deworming product Do not stack parasite products unless your veterinarian tells you to. Many preventives overlap in what they cover, and combining them can increase the risk of side effects without adding protection. If your cat is on a heartworm preventive, a flea product, and a dewormer, your vet should review the whole list together. For more on that topic, see [Heartworm Prevention for Cats: Why It's Important and How It Works](/knowledge/veterinary-medicine/preventive-and-routine-care/heartworm-prevention-for-cats-why-its-important-and-how-it-works). If your cat has a reaction to one isoxazoline product, your veterinarian may recommend a different drug class entirely. There are several feline-labeled options, and the right one depends on your cat's risk of fleas, ticks, heartworm, and intestinal worms where you live. See [Flea Prevention Dogs Cats](/knowledge/veterinary-medicine/parasitic-diseases/flea-prevention-dogs-cats) for how risk varies by region and lifestyle. ## Overdose and When to Call for Help An overdose can happen if a cat licks a freshly treated spot, if two people in the household each apply a dose, or if a cat chews into a dog product. Signs to watch for include vomiting, drooling, wobbliness, tremors, dilated pupils, and seizures. These can start within hours. If you think your cat received too much of any parasite product, call your veterinarian or a pet poison control hotline right away. Have the product name, the strength, and your best estimate of how much was involved. Do not wait for symptoms to appear before you call. If your cat is having a seizure, is struggling to breathe, or is collapsed, go to an emergency clinic immediately. Do not try to induce vomiting at home unless a veterinarian tells you to. ## Limitations and When to Contact a Veterinarian No parasite preventive covers every possible parasite, and no product works perfectly in every cat. Coverage depends on the specific product, the dose, and how consistently you apply it. Individual cases need a veterinarian who can examine your cat and review its history. Contact your veterinarian the same day if your cat: - Shows drooling, vomiting, or lethargy within 24 hours of a dose - Has redness, swelling, or hair loss at the application site that is spreading - Was given a dog product by mistake - Missed two or more monthly doses Go to an emergency clinic now if your cat: - Has a seizure, tremors, or cannot stand - Has facial swelling, hives, or difficulty breathing - Is unresponsive or has collapsed Schedule a routine visit if you want to switch products, if your cat has been scratching or losing hair for more than a few days, or if you are unsure whether your current preventive matches your cat's risk. Bring the packaging of everything you use. ## Frequently Asked Questions ### Can I give my cat Simparica or Simparica Trio? No. In the United States, both Simparica and Simparica Trio chewable tablets are approved for dogs, not cats. Giving a dog product to a cat can cause serious side effects. Ask your veterinarian for a feline-labeled alternative. ### What is the simparica equivalent for cats? The closest match is the topical combination of selamectin and sarolaner, sold as Revolution Plus in the U.S. It contains the same isoxazoline drug found in Simparica, paired with a second ingredient, and it is labeled for cats. Your veterinarian can confirm whether it fits your cat's needs. ### Does Simparica Trio for cats exist? Not as a U.S. product. Simparica Trio is a dog chewable that combines sarolaner, moxidectin, and pyrantel. Cats need a product formulated and dosed for them, and that means a feline-labeled option chosen by your veterinarian. ### How much does a cat parasite preventive cost? Prices vary widely by product, size, and where you buy it, and they change over time. Your veterinarian's office can give you a current price and explain what each product covers. Do not choose a preventive on price alone, because the parasites covered differ between products. ### What do cat owners say about these products? Owner surveys show that cat owners care about ease of application, product form, and how well a product fits their routine, and these preferences shape which preventive they choose [4]. If your cat is hard to pill, a spot-on may work better for you. Talk with your vet about what fits your household. ## Related Articles - [Revolution Plus For Cats](/knowledge/veterinary-medicine/clinical-methods/revolution-plus-for-cats) - [Preventive Care For Cats](/knowledge/veterinary-medicine/preventive-care/preventive-care-for-cats) - [FVRCP Vaccine for Cats: What It Covers and Why It Matters](/knowledge/veterinary-medicine/preventive-care/fvrcp-vaccine-for-cats) - [Heartworm Prevention for Cats: Why It's Important and How It Works](/knowledge/veterinary-medicine/preventive-and-routine-care/heartworm-prevention-for-cats-why-its-important-and-how-it-works) - [Flea Prevention Dogs Cats](/knowledge/veterinary-medicine/parasitic-diseases/flea-prevention-dogs-cats) - [Flea Treatment For Cats](/knowledge/veterinary-medicine/parasitic-diseases/flea-treatment-for-cats) - [Frontline for Cats: Active Ingredients Explained](/knowledge/veterinary-medicine/pet-medication-guide/frontline-cats-active-ingredients) - [Frontline for Cats: Dosage, Application, and Safety](/knowledge/veterinary-medicine/pet-medication-guide/frontline-cats-dosage-application) - [Revolution for Dogs and Cats: What It Treats and How to Use It](/knowledge/veterinary-medicine/pet-medication-guide/revolution-dogs-cats-guide) ## References 1. [A review of the parasiticidal efficacy of a selamectin plus sarolaner combination for use on cats](https://pubmed.ncbi.nlm.nih.gov/42736011/). Veterinary parasitology, regional studies and reports, 2026. 2. [Efficacy of sarolaner in Simparica® (sarolaner) chewables and Simparica Trio® (sarolaner, moxidectin, and pyrantel chewable tablets) against two US strains of Haemaphysalis longicornis](https://pubmed.ncbi.nlm.nih.gov/41521310/). Parasites & vectors, 2026. 3. [Efficacy of Revolution® Plus (selamectin plus sarolaner) for the prevention of transmission of Borrelia burgdorferi from infected Ixodes scapularis to cats](https://pubmed.ncbi.nlm.nih.gov/41845441/). Parasites & vectors, 2026. 4. [A Discrete Choice Experiment to Assess Cat Owners' Preferences for Topical Antiparasitics and the Comparative Ease of Use of a Combined Selamectin and Sarolaner Formulation: An International Survey](https://pubmed.ncbi.nlm.nih.gov/40646884/). Animals : an open access journal from MDPI, 2025. 5. [Efficacy of Revolution® Plus (selamectin plus sarolaner) against Amblyomma americanum (lone star ticks) in cats](https://pubmed.ncbi.nlm.nih.gov/40750907/). Parasites & vectors, 2025. ## Further Reading - [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) - [Cornell Feline Health Center: Health Information](https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information)