Pain management guide for dogs and cats per WSAVA 2022: assessment, NSAIDs, opioids, multimodal

WSAVA calls pain the “4th vital sign” — alongside temperature, pulse, and respiration. But how many small clinics in Southeast Asia systematically score pain at every case?

This article distills WSAVA 2022 + AAHA 2022 Pain Management Guidelines into quick-reference tables: assessment tools, NSAIDs, opioids, and adjunctive drugs, adapted for small clinics where opioid access may be limited.

Sources: WSAVA 2022, AAHA 2022, ISFM 2022, Merck Vet Manual. Reference material, not a prescribing protocol.

4 core principles

graph TD
    A[PAIN MANAGEMENT] --> B[Multimodal<br/>Combine multiple drugs/methods]
    A --> C[Pre-emptive<br/>Analgesia BEFORE pain onset]
    A --> D[Individualized<br/>By species, age, comorbidity]
    A --> E[Reassess<br/>Assess → treat → reassess]

Pain assessment tools

Tool	Species	Max score	Threshold	Best for
Glasgow CMPS-SF	Dog	24	≥6 = intervene	Gold standard, post-op
Glasgow CMPS-Feline	Cat	20	See licensed materials	Post-op, acute
Feline Grimace Scale	Cat	Facial action units	—	Quick bedside
CSU Canine	Dog	0-4/domain	Not standardized	Starting out

When to score? Baseline pre-op → 30 min post-extubation → every 2-4h in hospital.

Cats hide pain well. Signs: ear position, orbital tightening, hunched posture, hiding, decreased grooming, decreased appetite, unusual silence.

NSAIDs — quick reference

Drug	Dog	Cat	Notes
Carprofen	2.2 mg/kg q12h	2-4 mg/kg once periop	GI/renal/hepatic
Meloxicam	0.2 → 0.1 q24h	0.3 SC → 0.05 q24h	Cat long-term = jurisdiction-dependent
Robenacoxib	1-2 mg/kg q24h	2 SC (3d) / 1 PO q24h	Good for cat acute
Firocoxib	5 mg/kg q24h	—	OA dogs only
Grapiprant	2 mg/kg q24h	—	EP4 antagonist

⛔ Do NOT use NSAIDs with: GI disease, renal/hepatic compromise, coagulopathy, hypovolemia. Never combine with corticosteroids.

Opioids — quick reference

Drug	Dog	Cat	Route	Duration
Morphine	0.2-0.5 mg/kg	0.1-0.5	IV/IM/SC	q2-6h
Methadone	0.1-0.5	0.2-0.6	IV/IM/SC	q2-6h
Buprenorphine	0.005-0.02	0.005-0.04	IV/IM/OTM	q6-12h
Fentanyl	2-10 mcg/kg bolus	2-5 mcg/kg	IV/CRI	Continuous
Butorphanol	0.1-0.4	0.1-0.4	IV/IM/SC	q1-4h (ceiling)

⚠️ Tramadol in dogs: inconsistent efficacy — do not use as primary analgesic (WSAVA + AAHA).

Adjunctive drugs

Drug	Dose	Species	When
Gabapentin	5-10 mg/kg PO q8-12h	Dog/Cat	Neuropathic, chronic, anxiolytic
Ketamine	0.5 IV → 2-10 mcg/kg/min CRI	Dog/Cat	Severe acute, wind-up
Lidocaine	1-2 IV → 25-50 mcg/kg/min CRI	🔴 DOG ONLY	Somatic/visceral
Amantadine	3-5 mg/kg PO q24h	Dog/Cat	Chronic OA, NMDA
Maropitant	1 mg/kg SC/IV	Dog/Cat	Visceral + antiemetic

Opioid access in Southeast Asia

Country	Access	Reality
🇹🇭 Thailand	✅ Good	Morphine, tramadol common perioperatively
🇲🇾 Malaysia	✅ Permit	Buprenorphine/methadone via psychotropic permit
🇻🇳 Vietnam	⚠️ Limited	3-copy prescription, 7-day limit

When opioids are unavailable: Meloxicam + Gabapentin + Local blocks = workable multimodal for most cases.

⛔ Paracetamol — LETHAL in cats

Paracetamol/Acetaminophen is ABSOLUTELY CONTRAINDICATED in cats — causes methemoglobinemia and death.

Dogs: only when no alternative, 10-15 mg/kg q8-12h, hepatotoxicity risk.

Perioperative checklist — print for the OR

Phase	Task	Check
Pre-op	Baseline pain score (Glasgow/CSU)	☐
	Pre-emptive analgesia (NSAID + opioid/gabapentin)	☐
Intra-op	Local/regional block if applicable	☐
	CRI (ketamine/fentanyl/lidocaine) if needed	☐
Post-op	Reassess 30 min post-extubation	☐
	Score ≥6 Glasgow → rescue analgesia	☐
	Reassess every 2-4h in hospital	☐
Discharge	NSAID + gabapentin PO if needed	☐
	Educate owner on home pain signs	☐
Recheck	Reassess pain 3-5 days post-op	☐

Practice management software like VetGo can integrate pain scores into the medical record — auto-remind reassessment per protocol.

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Sources: WSAVA 2022 Pain Guidelines, AAHA 2022 Pain Guidelines, ISFM 2022 Feline Acute Pain, Merck Veterinary Manual.