Fenbendazole is a broad spectrum anthelmintic that has been in veterinary use for roughly six decades. It belongs to the benzimidazole carbamate family and has been successfully used against roundworms, hookworms and whipworms, as well as several tapeworm species. It acts as an antiparasitic agent by binding to b-tubulin in the parasite cell and causing it to disintegrate, killing the parasite (Correa, 1999). This drug is commonly given to pet poultry as an intestinal dewormer but has a strong track record of successful use against Capillaria as well.
In the laboratory, a fenbendazole diet was formulated for use in a rodent pinworm control program at our institution. During this treatment, established human lymphoma xenografts did not grow in C.B-17/Icr-Prkdcscid/Crl (SCID) mice, an observation that was unexpected as this xenograft model typically produces 80% to 100% tumor growth within 21 d. This unexpected result prompted further investigation of whether the fenbendazole-supplemented diet had an effect on the growth of the lymphoma xenografts.
SCID mice were fed 4 different diets: control diet, diet supplemented with fenbendazole, diet supplemented with vitamins only and a combination of fenbendazole and vitamin-supplemented diet. Initial white blood count values were similar among the groups, however at study termination, terminal total and neutrophil counts in mice receiving fenbendazole plus vitamins were significantly lower than in the controls (P = 0.014 and P = 0.009).
The fenbendazole-supplemented group also showed a decrease in tumor volume. These results indicate that fenbendazole in the diet inhibited human lymphoma xenograft growth, possibly through an antitumor effect.
In general, fenbendazole is safe for use in dogs and cats at recommended doses. However, it should never be given to pets during times of increased vulnerability, such as early adulthood, molting or pregnancy. Those who wish to give this medication should consult their veterinarian for specific directions and cautions. Fenbendazole is available in granule form or as a liquid suspension and should be given by mouth. This medication should be stored at room temperature and protected from sunlight. If you forget to give your pet his or her fenbendazole pill, don’t try to make up for it with extra pills at another time; this could cause an adverse reaction. fenben lab fenbendazol