Analgesia in the polytrauma dog: which opioid to choose
4-year-old German Shepherd hit by a car an hour ago, with a closed femoral fracture, vocalising and in severe pain on handling. After a crystalloid bolus it is normotensive.
Which analgesic is the most appropriate now?
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A. Butorphanol, because it is the safest opioid in trauma patients
Butorphanol is an agonist-antagonist with weak analgesic effect on somatic pain and very short duration (about 60 minutes in dogs). It is useful for sedation, not for severe orthopaedic pain.
B. Intravenous methadone, titrated to effect
Correct. Pure mu agonists (methadone, fentanyl, morphine) are the most potent, with a dose-dependent effect and no ceiling. Intravenously they act within minutes and can be adjusted; they are also reversible with naloxone.
C. Buprenorphine, because it lasts 6–8 hours and avoids redosing
It is a partial agonist with a ceiling effect and slow onset (30–45 minutes), suitable for mild to moderate pain. Because of its high mu-receptor affinity, if a pure agonist is needed later its effect may be less predictable.
D. Oral tramadol, because it does not depress cardiovascular function
In dogs tramadol produces little active metabolite (O-desmethyltramadol) and its analgesic efficacy is unreliable. In emergencies the oral route is also slow and unpredictable.
lightbulb Key takeaway
For severe pain in emergencies, use a pure mu agonist intravenously and titrated. Opioids have few cardiovascular effects and are safe in unstable patients; respiratory depression is of little relevance in dogs without intracranial disease. Buprenorphine for moderate pain and butorphanol for sedation or brief, mild pain.
References: WSAVA Guidelines for the Recognition, Assessment and Treatment of Pain (2022)
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Updated: October 31, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.