A benzimidazole drug, fenbendazole works by interfering with the parasite’s energy metabolism. The worms are unable to get the energy they need, and die. This medication is commonly used to treat intestinal parasites (roundworms, hookworms, whipworms, and the tapeworm genus Taenia), nematodes, giardia, and lungworms in dogs. It’s also being used in humans as part of a cancer treatment protocol known as the Joe Tippens protocol.

It’s safe to use for pregnant dogs, but the dosage needs to be lower. The most common brand is Panacur, but there are other brands available.

Most pets tolerate this medication well, but it can cause stomach upset or diarrhea in some animals. It’s also important to avoid feeding raw meat or fish while taking fenbendazole.

Side effects are rare, but if your pet experiences them, seek emergency veterinary care immediately. Symptoms of an allergic reaction to fenbendazole include facial swelling, itching, hives, shock, and vomiting.

In addition, if your dog has liver disease or poor kidney function, higher doses may be needed, or the dosage must be split. This is because severe renal or liver failure decreases the rate of drug excretion from the body.

Your vet may prescribe a compounded version of fenbendazole, if there’s a reason that the FDA-approved medication isn’t an option. These medications are made by a pharmacist and created on an individual basis for pets with specific health needs. They are not FDA-approved, but they are helpful for patients who have trouble swallowing pills in capsule form or those who are allergic to ingredients in commercially available medications.fenbendazole capsules