Sourced from published veterinary references. Awaiting credentialed clinical reviewer — our editorial process.
Butorphanol is dosed at 0.5–2 mg/kg IM once, preanesthetic/sedation in ball pythons, per Carpenter's Exotic Animal Formulary, 6th ed., Table 4.5 (Chemical restraint/anesthetic agents used in reptiles), p.236. Verify against current literature before clinical use.
Kappa-opioid receptor agonist and mu-opioid receptor antagonist. Provides visceral analgesia and sedation.
Side effects & warnings
Short duration of action (1-2 hours). Better for visceral than somatic pain. Ceiling effect on analgesia. May cause sedation and mild respiratory depression.
Species with Butorphanol dosing data (29 dose rules)
Each ExoticRx dose rule is graded by the strength of its primary evidence — see the editorial process.
Backed by 27 published sources
· Allweiler SI. How to improve anesthesia and analgesia in small mammals. Vet Clin North Am Exot Anim Pract. 2016;19:361-377. / 130. 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. doi:10.1016/j.cvex.2016.01.012 — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.790 (2026-08-01).
· Allweiler SI. How to improve anesthesia and analgesia in small mammals. Vet Clin North Am Exot Anim Pract. 2016;19:361-377. / 51. Flecknell PA. Analgesia and post-operative care. Laboratory Animal Anaesthesia; 2016:141-192. / 130. 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. doi:10.1016/j.cvex.2016.01.012 — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.790 (2026-08-01).
· BSAVA Small Animal Formulary, 10th ed, Part A (Canine and Feline), Butorphanol, printed p.55 (corpus lookup page 71)
Sample dosing (2 of 29 cited rules)
A dog/cat sample is shown here. Cited dosing for all 16 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.
Lascelles BDX, Robertson SA. Use of thermal threshold response to evaluate the antinociceptive effects of butorphanol in cats. Am J Vet Res. 2004;65(8):1085-1089. / 45. Ansah OB, Vainio O, Hellsten C, Raekallio M. Postoperative Pain Control in Cats: Clinical Trials with Medetomidine and Butorphanol. Vet Surg. 2002;31(2):99-103. doi:10.2460/ajvr.2004.65.1085 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.187 (2026-08-01).
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Brown SA. Clinical techniques in the ferret. Semin Avian Exot Pet Med. 1997;6:75-85. / 65. Ko JC, Marini RP. Anesthesia. In: Fox JG, Marini RP, eds. Biology and Diseases of the Ferret, 3rd ed., Wiley Blackwell, Ames, IA; 2014:259-283. PMID: 41235870 — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.943 (2026-08-01).
· Carpenter JW, Klaphake E, Gibbons PM, et al. Reptile formulary. In: Divers SJ, Stahl SJ, eds. Mader's Reptile and Amphibian Medicine and Surgery, 3rd ed., Elsevier, St. Louis, MO; 2019:1191-1211. / (green-iguana-specific row, p.252) 131. Fleming GJ, Robertson SA. Assessments of thermal antinociceptive effects of butorphanol and human observer effect on quantitative evaluation of analgesia in green iguanas (Iguana iguana). Am J Vet Res. 2012;73:1507-1511. — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.236 (2026-08-01).
· Carpenter's Exotic Animal Formulary, 6th Ed, Table 4.6, Butorphanol, p.236 (ref 33 = Bennett RA, Divers SJ, Schumacher J, et al. Roundtable: anesthesia. Bull Assoc Rept Amph Vet. 1999;9:20-27; ref 63 = Carpenter JW, Klaphake E, Gibbons PM, et al. Reptile formulary. In: Divers SJ, Stahl SJ, eds. Mader's Reptile and Amphibian Medicine and Surgery, 3rd ed. Elsevier; 2019:1191-1211). Frequency and the bearded-dragon-specific figure from BSAVA Small Animal Formulary 10th ed, Part B: Exotic Pets, Butorphanol, printed p.47 (PDF p.61; ref c = Greenacre CB, Takle G, Schumacher JP, et al. Comparative anti-nociception of morphine, butorphanol and buprenorphine versus saline in the green iguana using electrostimulation. J Herpetol Med Surg. 2006;16:88-92).
· Carpenter's Exotic Animal Formulary, 6th ed., Table 4.5 (Chemical restraint/anesthetic agents used in reptiles), p.236
· Curro TG, Brunson DB, Paul-Murphy J. Determination of the ED50 of isoflurane and evaluation of the isoflurane-sparing effect of butorphanol in cockatoos (Cacatua spp.). Vet Surg. 1994;23:429-433. / 764. Riggs SM, Hawkins MG, Craigmill AL, et al. Pharmacokinetics of butorphanol tartrate in red-tailed hawks (Buteo jamaicensis) and great horned owls (Bubo virginianus). Am J Vet Res. 2008;69:596-603. / 820. Sanchez-Migallon Guzman D, Flammer K, Paul-Murphy J, et al. Pharmacokinetics of butorphanol after oral, intravenous and intramuscular administration in Hispaniolan Amazon parrots (Amazona ventralis). J Avian Med Surg. 2011;25:185-191. doi:10.1111/j.1532-950x.1994.tb00502.x — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.448 (2026-08-01).
· Curro TG. Evaluation of the isoflurane-sparing effects of butorphanol and flunixin in psittaciformes. Proc Annu Conf Assoc Avian Vet; 1994:17-19.; Curro TG, Brunson DB, Paul-Murphy J. Determination of the ED50 of isoflurane and evaluation of the isoflurane-sparing effect of butorphanol in cockatoos (Cacatua spp.). Vet Surg. 1994;23:429-433. doi:10.1111/j.1532-950x.1994.tb00502.x — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.448 (2026-08-01).
· Greenacre CB, Schumacher JP, Talke G, et al. Comparative antinociception of morphine, butorphanol, and buprenorphine versus saline in the green iguana, Iguana iguana, using electrostimulation. J Herp Med Surg. 2006;16:88-92. doi:10.5818/1529-9651.16.3.88 — Verified against Mader's Reptile and Amphibian Medicine and Surgery, 3rd Ed, p.570 (2026-08-01).
· Heatley J. Hedgehogs. In: Mitchell MA, Tully TN Jr., eds. Manual of Exotic Pet Practice; Saunders/Elsevier, St. Louis, MO; 2009:433-455.; Johnson D. African pygmy hedgehogs. In: Meredith A, Johnson-Delaney C, eds. BSAVA Manual of Exotic Pets, 5th ed., British Small Animal Veterinary Association, Gloucester, UK; 2010:139-147. — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.742 (2026-08-01).
· Houghton KJ, Rech RH, Sawyer DC, et al. Dose-Response of Intravenous Butorphanol to Increase Visceral Nociceptive Threshold in Dogs. P Soc Exp Biol Med. 1991;197(3):290-296. doi:10.3181/00379727-197-43258 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.187 (2026-08-01).
· Lascelles BDX, Robertson SA. Use of thermal threshold response to evaluate the antinociceptive effects of butorphanol in cats. Am J Vet Res. 2004;65(8):1085-1089. / 45. Ansah OB, Vainio O, Hellsten C, Raekallio M. Postoperative Pain Control in Cats: Clinical Trials with Medetomidine and Butorphanol. Vet Surg. 2002;31(2):99-103. doi:10.2460/ajvr.2004.65.1085 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.187 (2026-08-01).
· Lascelles BDX, Robertson SA. Use of thermal threshold response to evaluate the antinociceptive effects of butorphanol in cats. Am J Vet Res. 2004;65(8):1085-1089. doi:10.2460/ajvr.2004.65.1085 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.187 (2026-08-01).
· Riggs SM, Hawkins MG, Craigmill AL, et al. Pharmacokinetics of butorphanol tartrate in red-tailed hawks (Buteo jamaicensis) and great horned owls (Bubo virginianus). Am J Vet Res. 2008;69:596-603. / 820. Sanchez-Migallon Guzman D, Flammer K, Paul-Murphy J, et al. Pharmacokinetics of butorphanol after oral, intravenous and intramuscular administration in Hispaniolan Amazon parrots (Amazona ventralis). J Avian Med Surg. 2011;25:185-191. doi:10.2460/ajvr.69.5.596 — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.448 (2026-08-01).
· Sanchez-Migallon Guzman D, Flammer K, Paul-Murphy J, et al. Pharmacokinetics of butorphanol after oral, intravenous and intramuscular administration in Hispaniolan Amazon parrots (Amazona ventralis). J Avian Med Surg. 2011;25:185-191. doi:10.1647/2009-054.1 — Verified against Carpenter's Exotic Animal Formulary, 6th Ed, p.448 (2026-08-01).
· Sawyer DC, Rech RH, Durham RA, Adams T, Richter MA, Striler EL. Dose response to butorphanol administered subcutaneously to increase visceral nociceptive threshold in dogs. Am J Vet Res. 1991;52(11):1826-1830. / 27. Houghton KJ, Rech RH, Sawyer DC, et al. Dose-Response of Intravenous Butorphanol to Increase Visceral Nociceptive Threshold in Dogs. P Soc Exp Biol Med. 1991;197(3):290-296. doi:10.2460/ajvr.1991.52.11.1826 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.187 (2026-08-01).
· Sawyer DC, Rech RH, Durham RA, Adams T, Richter MA, Striler EL. Dose response to butorphanol administered subcutaneously to increase visceral nociceptive threshold in dogs. Am J Vet Res. 1991;52(11):1826-1830. doi:10.2460/ajvr.1991.52.11.1826 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.187 (2026-08-01).
· Sladky KK, Kinney ME, Johnson SM. J Am Vet Med Assoc 2008;233(2):267-273. doi:10.2460/javma.233.2.267PMID:18627230 — bearded dragon (Pogona vitticeps), butorphanol 2 or 20 mg/kg SC: did NOT alter thermal withdrawal latency at 2-24 h, while morphine did. Documents this dose in this species; does not demonstrate analgesia.