Key takeaways:
Fenbendazole (Panacur, Panacur C) is an antiparasite medication for dogs that treats intestinal worms and other parasites, such as Giardia.
Fenbendazole is considered safe for most dogs, and side effects are rare.
If your dog is prescribed fenbendazole, it’s given as a tablet, oral liquid, or as granules that are mixed into their food.
Does your dog have parasites? Common intestinal worms cause a variety of impacts in dogs, including vomiting and diarrhea. Some intestinal parasites suck blood, causing anemia. So it’s important to treat intestinal parasites with an effective dewormer, such as fenbendazole (Panacur, Panacur C).
This common medication treats a number of canine parasites. These include both common intestinal worms and uncommon parasitic infections. Fortunately, this is a safe medication with a low risk of side effects.
Read on to learn more about fenbendazole for dogs.
Common names | Fenbendazole (Panacur, Panacur C) |
What it treats | Intestinal parasites, including hookworms, roundworms, and whipworms |
How it comes (forms) | Tablets, oral liquid, granules to mix in food |
Common side effects | Nausea, loss of appetite, vomiting, diarrhea |
Fenbendazole is an antiparasitic drug, which means it kills parasites. It affects a number of parasite cell functions, but it mostly blocks their energy production. When cells can no longer produce energy, they die. This causes the parasite to die.
Fenbendazole is FDA-approved to treat many common intestinal parasites in dogs. It’s used as a dewormer for dogs with a variety of intestinal parasites. Intestinal parasites treated with fenbendazole include:
Veterinarians also use fenbendazole to treat less common dog parasites, such as:
Tracheal worms
Bladder worms
Kidney worms
The parasites on these lists are not the only ones that can be treated with fenbendazole. Veterinarians also use fenbendazole to treat other parasitic infections. If your dog has parasites, your veterinarian will decide if fenbendazole is an appropriate and effective treatment option.
Your veterinarian will determine the best fenbendazole dosage for your dog. This will be based on your dog’s weight and the specific parasite they’re being treated for. Some parasites require higher doses of fenbendazole, while others respond to low doses of fenbendazole.
Fenbendazole comes in a number of forms, including:
Tablets
Liquid suspension taken by mouth
Granules that are mixed with food
Some parasites are treated with just two doses of fenbendazole, given 30 days apart. Other parasites need to be treated twice daily for several weeks. Your dog’s treatment plan will depend on the specific parasite that is causing their infection.
Follow your veterinarian’s dosing instructions closely. This will maximize the likelihood of successful treatment while reducing the risk of side effects.
Overall, fenbendazole is considered a very safe medication for dogs. Side effects are usually mild. Fenbendazole side effects may include:
If your dog develops gastrointestinal (GI) signs while taking fenbendazole, contact your veterinarian for guidance. In some cases, GI signs are caused by a massive parasite die-off and not necessarily by the medication.
In 12 reported cases, long-term use of fenbendazole caused bone marrow suppression in dogs. Bone marrow suppression causes dogs to become anemic and have low blood cell counts.
Bone marrow suppression has only been seen in dogs receiving fenbendazole for an unusually long period of time. A typical course of fenbendazole will not affect your dog’s bone marrow.
Fenbendazole does not interact with any other common canine medications. But it’s still best to make sure your veterinarian is aware of other medications your dog takes. These include prescription medications, over-the-counter medications, and nutritional supplements.
If you forget to give your dog a dose of fenbendazole, give the missed dose as soon as you remember.
But if it’s almost time for your dog’s next dose, skip the missed dose and resume your dog’s regular dosing schedule. Do not give them a double dose of fenbendazole.
Fenbendazole (Panacur, Panacur C) is a safe and effective antiparasite medication for dogs. Veterinarians use fenbendazole to treat a variety of parasites, including roundworms, hookworms, whipworms, Giardia, lungworms, and others.
Follow your veterinarian’s dosing instructions closely when giving your dog fenbendazole. This will reduce the risk of side effects and increase its ability to get rid of your dog’s parasitic infection. If you see any side effects while your dog is taking fenbendazole, contact your veterinarian.
Ballweber, L. R. (2018). Lungworm infection in dogs. Merck Veterinary Manual.
Brooks, W. (2023). Fenbendazole (Panacur). Veterinary Partner.
Brooks, W. (2023). Taenia species tapeworms in dogs and cats. Veterinary Partner.
Centers for Disease Control and Prevention. (2024). About Giardia and pets.
Cohen, A. (n.d.). Roundworms. Cornell Richard P. Riney Canine Health Center.
Merck Sharp & Dohme. (2024). Panacur- fenbendazole granule [package insert].
U.S. Food and Drug Administration. (2024). Dear Veterinarian letter regarding adverse events associated with extra-label use of fenbendazole in dogs.
U.S. Food and Drug Administration. (n.d.). Supplemental New Animal Drug Application: Intervet Inc.