Side Effects of Fenbendazole

Fenbendazole is a medication used to treat parasites found in the stomach and intestines of animals, including household pets such as cats and dogs. Common animal parasites include hookworm, tapeworm and roundworm. Fenbendazole, which is classified as an anthelmintic drug, is available in several forms, including granules, pastes and oral suspensions, to make it easier to administer to pets. Fenbendazole is a generic drug, but it is also available under the brand name Panacur.

  1. Vomiting

    • Some cats and dogs may vomit shortly after they ingest the drug, although most animals will not have any problems. Vomiting is no cause for concern, but if your pet does vomit after taking fenbendazole, do not readminister the medication.

    Nausea

    • Some pets taking fenbendazole may experience nausea as a result of the medication. Because your pet cannot communicate with you that it is nauseated, you may notice the animal not acting like itself, including being less active and lethargic.

    Allergic Reaction

    • In rare cases, an animal taking fenbendazole may have an allergic reaction to the drug. Common signs of an allergic reaction in animals include swelling of the head and face, difficulty breathing, hives or other skin rashes, and vomiting. If your pet is having an allergic reaction, contact your veterinarian immediately and seek medical attention.

    Dosing

    • Fenbendazole is not usually effective at eliminating parasites when given as a one-time dose. Instead, most veterinarians will recommend a three-day course of the medication, with one dose given on three consective days. Dosing depends on your pet's weight, with 25 milligrams prescribed per pound. Always give your pet the entire course of medication, even if it seems as though it is feeling better.

    Symptoms

    • There are several signs and symptoms that your dog or cat may have a parasite such as roundworm, hookworm or tapeworm. Among the common symptoms are diarrhea, excessive coughing, and a change in your pet's coat or appetite. If you suspect your pet has a parasite, contact your veterinarian. Parasites can typically be diagnosed through a simple test on a fecal sample.