Fenbendazole

Indications

Panacur ® Granules 22.2% is used for control of the following internal parasites of the families Felidae and Ursidae . Felidae : Lions (Panthera leo) . For control of ascarids (Toxocara cati, Toxascaris leonina) , hookworms (Ancylostoma spp. ) . Tigers (Panthera tigris) . For control of ascarids (Toxocara cati, Toxascaris leonina) , hookworms (Ancylostoma spp. ) . Cheetahs (Acinonyx jubatus) . For control of ascarids (Toxocara cati, Toxascaris leonina) . Pumas (Felis concolor) , Panthers (Panthera spp. ) , Leopards (Panthera pardus) , Jaguars (Panthera onca) . For control of ascarids (Toxocara cati, Toxascaris leonina) , hookworms (Ancylostoma spp. ) , tapeworms (Taenia hydatigena, T. krabbei, T. taeniaeformis) . Ursidae : Black Bears (Ursus americanus) . For control of ascarids ( Baylisascaris transfuga, Toxascaris leonina) , hookworms (Ancylostoma caninum) , tapeworms (Taenia hydatigena, T. krabbei) . Polar Bears (Ursus maritimus) and Grizzly Bears (Ursus horribilis) . For control of ascarids (Baylisascaris transfuga, Toxascaris leonina) . DIRECTIONS Efficacy is dependent on the correct dose level based on body weight over the appropriate treatment period. When possible, animals should be weighed to determine body weight accurately, otherwise weights can be estimated. It is important that the appropriate dose of Panacur ® be ingested. This may best be accomplished by applying the granules as a top dressing or mixing with a small portion of the food prior to offering the main meal. Refer to the DOSAGE AND ADMINISTRATION portion of the labeling for determining the appropriate dose for each species of animal.

Dosage and Administration

The dose for Felidae and Ursidae is 10 mg/kg BW daily for 3 consecutive days. Please see INDICATIONS for details as to claims for animal and parasite. Directions: The daily dose of 10 mg/kg (4.54 mg/lb) can be achieved as follows: Using a gram scale, weigh out 1 gram of Panacur ® Granules 22.2% for each 22 kg or 50 lbs body weight. TOXICOLOGY DATA Panacur ® has been fed to pregnant and non-pregnant females and to male animals including Felidae and Ursidae at ten times the recommended dose for twice the recommended treatment period without effect on reproduction. In one puma and one jaguar, ten times the recommended dose given for twice the recommended duration showed evidence of inappetence when administered the Panacur ® Granules. SIDE EFFECTS In studies conducted in a variety of captive animals, loose stools have been reported in pumas, black bears, and ruminants. In one puma and one jaguar, periods of inappetence followed the initial consumption of fenbendazole at ten times the recommended treatment level. DRUG REACTIONS There are currently no data available to support the use of Panacur ® Granules 22.2% in conjunction with other nutritional and drug substances in Felidae and Ursidae . However, experience with the drug under actual conditions of use has not revealed any incompatibilities with Panacur ® .

Contraindications

None known. TOXICOLOGY DATA Panacur ® Granules 22.2% did not cause toxicity when administered to weaned pups at doses equal to 5 times the recommended daily dose and for 2 times the duration of treatment.

Precautions

Medicated food must be fully consumed for Panacur ® to be effective. FOR DOGS

Adverse Reactions

Another benzimidazole has been reported to cause hepatotoxicity clinically in canines. However, this effect has not been reported during the clinical use of fenbendazole. In US clinical studies, 3 of 240 dogs vomited which may have been drug related. DRUG REACTIONS Panacur ® Granules 22.2% has been administered to dogs in clinical trials along with a wide variety of other drugs including antibiotics, steroids, anesthetics, tranquilizers, vitamins, and minerals. No incompatibilities with other drugs are known at this time.

Description

Panacur ® (fenbendazole) Granules 22.2% contains the active anthelmintic, fenbendazole. The chemical name of fenbendazole is methyl 5-(phenylthio)-2-benzimidazole carbamate. The CAS Registry Number is 43210-67-9. The chemical structure is: Panacur ® Granules 22.2% contains 222 mg/g of fenbendazole. Chemical Structure ACTIONS The antiparasitic action of Panacur ® Granules 22.2% is believed to be due to the inhibition of energy metabolism in the parasite. FOR THE FOLLOWING CARNIVOROUS/OMNIVOROUS ANIMALS Lions (Panthera leo) , Tigers (Panthera tigris) , Cheetahs (Acinonyx jubatus) , Pumas (Felis concolor) , Jaguars (Panthera onca) , Leopards (Panthera pardus) , Panthers (Panthera spp. ) , Grizzly Bears (Ursus horribilis) , Polar Bears (Ursus maritimus) , Black Bears (Ursus americanus) CAUTION: Do not use 14 days before or during the hunting season.

FDA adverse event reports

The FDA Center for Veterinary Medicine publishes the adverse event reports it receives through openFDA. The counts below are the reports naming fenbendazole as an active ingredient for each species this label names, as returned on 2026-09-16, coded by the VeDDRA reaction term the reporter chose. Reactions are counted per report, so one report can appear under several terms.

These are counts, not rates. Reporting is voluntary, the number of animals treated is not known, and a widely used product accumulates reports for that reason alone. A report records that an event followed a dose; it does not establish that the product caused it. The counts say nothing about how one product compares with another.