Fenbendazole, also called FBZ, is one of several medications that can kill internal parasites that are causing illness and discomfort for your pet. It is a member of the benzimidazole family of anti-parasitic drugs and is considered to be a broad spectrum medication. It is commonly used to treat and/or prevent gastrointestinal parasites such as roundworms, hookworms, whipworms, the tapeworm genus Taenia, and pinworms. It can also be used to treat giardia and lungworms in dogs.
This medication can be administered orally or topically. It comes in granules, tablets, and oral suspensions. In general, fenbendazole is well-tolerated by pets and rarely causes side effects. It is usually taken orally as directed by a veterinarian and is effective at killing parasites in just a few days. It is generally given as a one-time dose, but in some cases the drug may need to be given over a period of time. Depending on the condition being treated, how well your pet responds to the medication, and whether or not there are any adverse reactions, the length of treatment will vary.
When administered orally, fenbendazole is absorbed from the intestinal tract and into the bloodstream, where it is distributed throughout the body. It is primarily active in the central nervous system where it inhibits microtubule assembly and cell division by binding to tubulin. This leads to the disabling of cellular respiration and death of the parasite. It also has a number of other actions in the body including binding to and blocking amino acids, inhibiting protein synthesis, and blocking lipid synthesis.
It has been reported that fenbendazole has anti-tumor activities in mice. This is likely due to its ability to block amino acid synthesis and its ability to alter the structure of mitochondria. It is not yet approved for use in humans, but research into its cancer-fighting properties is ongoing.
There are similarities between the structures of parasites and cancer cells, leading some people to believe that anthelmintics, like fenbendazole, could be used as a cancer treatment. However, as of 2020 no peer-reviewed studies have found that fenbendazole or other anthelmintics are effective in curing cancer.
In veterinary medicine, fenbendazole is most often prescribed to treat gastrointestinal parasites in both large and small animals. In dogs, fenbendazole is very effective against roundworms, hookworms, whipworms, and the tapeworm genus Taenia. It can also be used to treat a number of other internal parasites such as giardia, hepatobiliary trematodes, and the lungworms Giardia lamblia and Dipylidium caninum.
It is not currently approved for use in cats, but is frequently prescribed off-label to treat feline gastrointestinal parasites such as the nematode Aelurostrongylus abstrusus, cestodes Heterobilharzia americana and Nanophyetus salmincola, and trematodes Strongyloides stercoralis and Paragonimia kellicotti.
Fenbendazole is well-tolerated in cats and has been reported to be safe at five times the recommended dosage and for three times the duration of a prescription for dogs. Side effects are rare and include vomiting, diarrhea, constipation, and loss of appetite. fenbendazole capsules