Sourced from published veterinary references. Awaiting credentialed clinical reviewer — our editorial process.
Fenbendazole is dosed at 50–100 mg/kg PO once in ball pythons, per Plumb's Fenbendazole REPTILES, corpus p.534; Carpenter's 6th ed. Table 4.4, p.225, ball-python-specific row; Mader's Table 127.4, corpus p.1406 ('All species/nematodes'). Verify against current literature before clinical use.
Binds to beta-tubulin, inhibiting microtubule polymerization in parasites. Disrupts energy metabolism and cell division.
Side effects & warnings
Very wide safety margin. Rarely causes vomiting or diarrhea. Safe in pregnant animals at standard doses. Must be given for multiple consecutive days for efficacy.
Species with Fenbendazole dosing data (31 dose rules)
Each ExoticRx dose rule is graded by the strength of its primary evidence — see the editorial process.
Backed by 23 published sources
· Adamcak A, Otten B. Rodent therapeutics. Vet Clin North Am Exot Anim Pract. 2000;3:221-237.; Meredith A. BSAVA Small Animal Formulary: Part B: Exotic Pets, British Small Animal Veterinary Association, Quedgeley, Gloucester, UK; 2015.; Morrisey JK, Carpenter JW. Formulary. In: Quesenberry KE, Carpenter JW, eds. Ferrets, Rabbits, and Rodents: Clinical Medicine and Surgery, 4th ed., Elsevier, St. Louis, MO; 2021:620-630. — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.776 (2026-08-01).
· Bailey TA, Apo MM. Pharmaceutics commonly used in avian medicine. In: Samour J, eds. Avian Medicine, 3rd ed., Mosby Elsevier, Edinburgh, Scotland; 2016:637-678. doi:10.1016/b978-0-7234-3832-8.00023-7; Hawkins MG, Barron H, Speer BL, et al. Birds. In: Carpenter JW, eds. Exotic Animal Formulary, 4th ed., Elsevier Saunders, St. Louis, MO; 2013:183-437. — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.434 (2026-08-01).
· Beck W, Pantchev N. Praktische Parasitologie bei Heimtieren, Schluetersche Verlagsgesellschaft MBH & Co, Hannover, Germany; 2006.; Visser C, Wijnbergen A, Bleich A. Maeuse und ratten. In: Fehr M, Sassenburg L, Zwart P, eds. Krankheiten der Heimtiere, Schluetersche Verlagsgesellschaft, Hannover, Germany; 2015. — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.776 (2026-08-01).
Sample dosing (2 of 31 cited rules)
A dog/cat sample is shown here. Cited dosing for all 20 species — reptiles, birds, pocket pets, livestock, and equine — is free on the per-species pages above. Pro adds the weight-based calculator for every species.
Upgrade to Pro or Student to unlock the full dose ranges and frequency for every species. The drug's mechanism, warnings, indications, and cited sources are free to read.
· Gruffydd-Jones T, Addie D, Belak S, et al. Giardiasis in cats: ABCD guidelines on prevention and management. J Feline Med Surg. 2013;15(7):650-652. PMID: 23813834 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.533 (2026-08-01).
· Johnson R, Hemsley S. Gliders and possums. In: Vogelnest L, Woods R, eds. Medicine of Australian Mammals; CSIRO Publishing, Clayton South, Vic; 2008:395-437.; Ness RD, Johnson-Delaney C. Sugar gliders. In: Quesenberry KE, Carpenter JW, eds. Ferrets, Rabbits, and Rodents: Clinical Medicine and Surgery, 3rd ed., Saunders/Elsevier, St. Louis, MO; 2012:393-410.; Morrisey JK, Carpenter JW, et al. Formulary. In: Quesenberry KE, Orcutt CJ, Mans C, et al. Ferrets, Rabbits, and Rodents: Clinical Medicine and Surgery, 4th ed., Elsevier, St. Louis, MO; 2021:620-630. — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.706 (2026-08-01).
· Johnson-Delaney C. Exotic Companion Medicine Handbook for Veterinarians, Zoological Education Network, Lake Worth, FL; 2008.; Morrisey JK, Carpenter JW, et al. Formulary. In: Quesenberry Q, Orcutt C, Mans C, et al. Ferrets, Rabbits and Rodents: Clinical Medicine and Surgery, 4th ed., Elsevier, St. Louis, MO; 2021:620-630. — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.737 (2026-08-01).
· Morrisey JK. Ectoparasites of ferrets and rabbits. Proc North Am Vet Conf; 1998:844-845. — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.936 (2026-08-01).
· Plumb's Veterinary Drug Handbook, Fenbendazole, REPTILES section, corpus p.534; Mader's Table 127.4, corpus p.1406 (printed 1196)
· Plumb's Veterinary Drug Handbook, Fenbendazole, REPTILES section, corpus p.534; Mader's Table 127.4, corpus p.1406, '25-100 mg/kg PO q14d for up to 4 treatments - All species/nematodes'
· Suter C, Muller-Doblies UU, HattJM, et al. Prevention and treatment of Encephalitozoon cuniculi infection in rabbits with fenbendazole. Vet Rec. 2001;148:478-480. doi:10.1136/vr.148.15.478 — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.850 (2026-08-01).
· Suter C, Muller-Doblies UU, HattJM, et al. Prevention and treatment of Encephalitozoon cuniculi infection in rabbits with fenbendazole. Vet Rec. 2001;148:478-480. doi:10.1136/vr.148.15.478; Mencke N, Bach T. Managing gastrointestinal helminths in small mammals. Comp Cont Educ Pract. 2007;29:13-16. — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.850 (2026-08-01).
· Verified against Papich/Saunders Handbook of Veterinary Drugs, 4th Ed, p.344 (2026-08-01).