Table: Selected Analgesics for Use in Dogs-Merck Veterinary Manual

Selected Analgesics for Use in Dogs

Drug	Class	Pain category	Intermittent dosage regimen	Epidural dosage	CRI^a dosage regimen	Comments
Alfentanil	Opioid	Acute	NA—very short acting	NA—very short acting	0.5–1 mcg/kg IV followed by 0.5–1 mcg/kg/minute IV CRI	DEA Schedule II. Short acting opioid given by CRI to achieve effect.
Bupivacaine	Local anesthetic	Acute	Injectable solution: 1–2 mg/kg locally (not IV); liposomal injectable product: 5.3 mg/kg infiltrated into the surgical site at closure	Preservative-free injectable 0.5% solution: 1–2 mg/kg	Not for IV use	Not for IV use. Systemic administration has resulted in severe cardiac and CNS toxicity including death. Products combined with epinephrine will prolong the duration of local effect and reduce the likelihood of systemic toxicity.
Buprenorphine	Opioid partial antagonist/agonist	Acute	Injectable 0.03% solution: 0.005–0.03 mg/kg) IV or IM q 4–6 h; 0.12 mg/kg transmucosal q 4–8 h	0.004 mg/kg	Injectable 0.03% solution: 0.005–0.01 mg/kg), followed by 0.002–0.004 mg/kg/h IV CRI	DEA Schedule III. Long-acting concentrated 1.8 mg/ml injection is not typically used in dogs.
Butorphanol	Opioid partial antagonist/agonist	Acute	0.2–0.4 mg/kg IV, IM, SC q 1–2 h	0.25 mg/kg	0.2 mg/kg IV as a loading dose followed by 0.1–0.24 mg/kg/h IV CRI	DEA Schedule IV. Dosages are reduced in dogs with the ABCB1-1Delta genetic mutation.
Carprofen	NSAID	Acute/chronic	4.4 mg/kg/day (may be divided q 12 h) PO, SC, IV	Not for epidural use	Not for CRI	Monitor hepatic enzymes to detect idiosyncratic hepatotoxicity
Deracoxib	NSAID	Acute/chronic	Postoperative analgesia: 3–4 mg/kg PO once daily as needed, not to exceed 7 days; chronic pain: 1–2 mg/kg PO once daily as needed	Not for epidural use	Not for CRI	Do not confuse higher short-term postoperative dosage with lower chronic dosage.
Dexmedetomidine	Alpha-2 adrenergic receptor agonist	Acute	0.005–0.02 mg/kg IV, IM, SC for short, painful procedures	0.003–0.006 mg/kg	0.001–0.002 mg/kg followed by 0.0007–0.001 mg/kg/h IV CRI	Transmucosal dexmedetomidine is not typically used for analgesia in dogs.
Fentanyl	Opioid	Acute	Transdermal patch: 0.001–0.005 mg/kg/h rounded to the nearest 12.5 mcg, 25 mcg, 50 mcg, 75 mcg, or 100 mcg patch	0.004 mg/kg, diluted with 0.2 mL preservative-free normal saline	0.01 mg/kg IV loading dose, followed by 0.01 mg/kg/h IV CRI	DEA Schedule II. Note delayed onset of analgesia (12–24 h) limits utility as an initial monotherapy for acute pain.
Firocoxib	NSAID	Acute/chronic	5 mg/kg PO q 24 h	Not for epidural use	Not for IV use	Firocoxib injection is approved for horses and typically not used in dogs.
Gabapentin	GABA^b receptor agonist	Chronic	10–15 mg/kg PO q 8 h	Not for epidural use	Not for IV use	Gabapentin is a reportable controlled substance in some states in the US.
Hydromorphone	Opioid	Acute	0.05–0.2 mg/kg IV, IM, or SC every 2–4 hours	0.03–0.04 mg/kg	0.025–0.05 mg/kg IV followed by 0.03 mg/kg/h IV CRI	DEA Schedule II.
Ketamine	NMDA^c receptor antagonist	Acute	3–5 mg/kg IV as a perioperative analgesic adjunctive therapy	Not recommended	0.5–1 mg/kg IV followed by 0.12–0.6 mg/kg/h IV CRI	DEA Schedule III. Ketamine may be neurotoxic when administered by the epidural or intrathecal route.
Lidocaine	Local anesthetic	Acute	4–6 mg/kg local infiltration	Preservative free: 4.4 mg/kg	1–2 mg/kg IV followed by 20–50 mcg/kg/minute IV CRI
Maropitant	NK-1^d receptor antagonist	Acute	1 mg/kg SC, IV	Not for epidural use	1 mg/kg IV over 1–2 minutes followed by 0.03 mg/kg/h IV CRI	Rapid injection of maropitant by the intravenous route may cause severe hypotension. Refrigerating the injection may reduce the pain associated with SC injection.
Meloxicam	NSAID	Acute/chronic	0.2 mg/kg PO, IV, or SC followed by 0.1 mg/kg PO q 24 h	Not for epidural use	Not for CRI
Meperidine	Opioid	Acute	3–5 mg/kg IM, SC q 1–2 h	Not for epidural use	Not for IV use	DEA Schedule II. Also known as pethidine. Do not administer IV due to histamine release. May be painful on IM or SC injection.
Mepivacaine	Local anesthetic	Acute	1–5 mg/kg local infiltration	3–4.5 mg/kg	Not for IV use	Not for IV use. Systemic administration has resulted in severe cardiac and CNS toxicity including death.
Methadone	Opioid	Acute	0.1–1 mg/kg IM, SC, IV q 4–8 h	0.1 mg/kg	0.1–0.2 mg/kg IV followed by 0.12 mg/kg/h IV CRI	DEA Schedule II. Oral bioavailability is limited in dogs.
Morphine	Opioid	Acute	0.5–1 mg/kg IM, SC, or IV (slowly)	Preservative free: 0.1 mg/kg	0.3–0.5 mg/kg IV (slowly) followed by 0.1–1 mg/kg/h IV CRI.	DEA Schedule II. Rapid IV administration causes CNS excitation.
Oxymorphone	Opioid	Acute	0.05–0.2 mg/kg IV, IM, SC q 1–6 h	Preservative free: 0.05–0.1 mg/kg	0.02–0.1 mg/kg followed by 0.01–0.02 mg/kg/h IV CRI ^e,f	No longer commercially available in the US.
Prednisone/Prednisolone	Corticosteroid	Chronic	0.5–1 mg/kg PO q 24 h	Not for epidural use	Not for IV use	Do not use concurrently with NSAIDs.
Pregabalin	GABA receptor agonist	Chronic	2–5 mg/kg PO q 8–12 h	Not for epidural use	Not for IV use	DEA Schedule IV.
Remifentanil	Opioid	Acute	NA due to extremely short duration of action.	NA due to extremely short duration of action.	1 mcg/kg IV followed by 0.1–0.3 mcg/kg/minute IV CRI.	DEA Schedule II.
Robenacoxib	NSAID	Acute/chronic	2 mg/kg SC for up to 3 days; 1 mg/kg PO q 24 h	Not for epidural use	Not for IV use
Ropivacaine	Local anesthetic	Acute	2 mg/kg as a local infiltration	0.2–1.65 mg/kg	Not for IV use	Not for IV use. Systemic administration has resulted in severe cardiac and CNS toxicity including death.
Sufentanil	Opioid	Acute		0.5–1 mcg/kg	0.5–1 mcg/kg slow IV followed by 0.5–1 mcg/kg/h IV CRI	DEA Schedule II.
Tramadol	Synthetic opioid	Acute/chronic	4–10 mg/kg PO q 6–8	Not for epidural use	Not for IV use	DEA Schedule IV.
Xylazine	Alpha-2 adrenergic receptor agonist	Acute	0.05–0.5 mg/kg IV, IM, or SC as an adjunctive therapy.	Not for epidural monotherapy	Not for use as CRI	Not suitable for analgesic monotherapy.
^a CRI=constant-rate infusion. ^b GABA=gamma-aminobutyric acid. ^c NMDA=N-methyl-D-aspartate. ^d NK-1=neurokinin-1 ^eMathews KA. Small animal practice update on management of pain. Vet Clin North Am. 2008;38(6):1435. ^fSmith LJ, Yu JK, Bjorling DE, Waller K. Effects of hydromorphone or oxymorphone, with or without acepromazine, on preanesthetic sedation, physiologic values, and histamine release in dogs. J Am Vet Med Assoc. 2001;218(7):1101-1105. ^gHerrera Becerra JR, Monteiro ER , Martins LGB, Baier ME, Santos EA, Bianchi SP. Epidural administration of combinations of ropivacaine, morphine and xylazine in bitches undergoing total unilateral mastectomy: a randomized clinical trial. Vet Anesth Analg. 2022;49(1):126-134.

Drug

Class

Pain category

Intermittent dosage regimen

Epidural dosage

CRI^a dosage regimen

Comments

Alfentanil

Opioid

Acute

NA—very short acting

0.5–1 mcg/kg IV followed by 0.5–1 mcg/kg/minute IV CRI

DEA Schedule II. Short acting opioid given by CRI to achieve effect.

Bupivacaine

Local anesthetic

Acute

Injectable solution: 1–2 mg/kg locally (not IV); liposomal injectable product: 5.3 mg/kg infiltrated into the surgical site at closure

Preservative-free injectable 0.5% solution: 1–2 mg/kg

Not for IV use

Not for IV use. Systemic administration has resulted in severe cardiac and CNS toxicity including death. Products combined with epinephrine will prolong the duration of local effect and reduce the likelihood of systemic toxicity.

Buprenorphine

Opioid partial antagonist/agonist

Acute

Injectable 0.03% solution: 0.005–0.03 mg/kg) IV or IM q 4–6 h; 0.12 mg/kg transmucosal q 4–8 h

0.004 mg/kg

Injectable 0.03% solution: 0.005–0.01 mg/kg), followed by 0.002–0.004 mg/kg/h IV CRI

DEA Schedule III. Long-acting concentrated 1.8 mg/ml injection is not typically used in dogs.

Butorphanol

Opioid partial antagonist/agonist

Acute

0.2–0.4 mg/kg IV, IM, SC q 1–2 h

0.25 mg/kg

0.2 mg/kg IV as a loading dose followed by 0.1–0.24 mg/kg/h IV CRI

DEA Schedule IV. Dosages are reduced in dogs with the ABCB1-1Delta genetic mutation.

Carprofen

NSAID

Acute/chronic

4.4 mg/kg/day (may be divided q 12 h) PO, SC, IV

Not for epidural use

Not for CRI

Monitor hepatic enzymes to detect idiosyncratic hepatotoxicity

Deracoxib

NSAID

Acute/chronic

Postoperative analgesia: 3–4 mg/kg PO once daily as needed, not to exceed 7 days; chronic pain: 1–2 mg/kg PO once daily as needed

Not for epidural use

Not for CRI

Do not confuse higher short-term postoperative dosage with lower chronic dosage.

Dexmedetomidine

Alpha-2 adrenergic receptor agonist

Acute

0.005–0.02 mg/kg IV, IM, SC for short, painful procedures

0.003–0.006 mg/kg

0.001–0.002 mg/kg followed by 0.0007–0.001 mg/kg/h IV CRI

Transmucosal dexmedetomidine is not typically used for analgesia in dogs.

Fentanyl

Opioid

Acute

Transdermal patch: 0.001–0.005 mg/kg/h rounded to the nearest 12.5 mcg, 25 mcg, 50 mcg, 75 mcg, or 100 mcg patch

0.004 mg/kg, diluted with 0.2 mL preservative-free normal saline

0.01 mg/kg IV loading dose, followed by 0.01 mg/kg/h IV CRI

DEA Schedule II. Note delayed onset of analgesia (12–24 h) limits utility as an initial monotherapy for acute pain.

Firocoxib

NSAID

Acute/chronic

5 mg/kg PO q 24 h

Not for epidural use

Not for IV use

Firocoxib injection is approved for horses and typically not used in dogs.

Gabapentin

GABA^b receptor agonist

Chronic

10–15 mg/kg PO q 8 h

Not for epidural use

Not for IV use

Gabapentin is a reportable controlled substance in some states in the US.

Hydromorphone

Opioid

Acute

0.05–0.2 mg/kg IV, IM, or SC every 2–4 hours

0.03–0.04 mg/kg

0.025–0.05 mg/kg IV followed by 0.03 mg/kg/h IV CRI

DEA Schedule II.

Ketamine

NMDA^c receptor antagonist

Acute

3–5 mg/kg IV as a perioperative analgesic adjunctive therapy

Not recommended

0.5–1 mg/kg IV followed by 0.12–0.6 mg/kg/h IV CRI

DEA Schedule III. Ketamine may be neurotoxic when administered by the epidural or intrathecal route.

Lidocaine

Local anesthetic

Acute

4–6 mg/kg local infiltration

Preservative free: 4.4 mg/kg

1–2 mg/kg IV followed by 20–50 mcg/kg/minute IV CRI

Maropitant

NK-1^d receptor antagonist

Acute

1 mg/kg SC, IV

Not for epidural use

1 mg/kg IV over 1–2 minutes followed by 0.03 mg/kg/h IV CRI

Rapid injection of maropitant by the intravenous route may cause severe hypotension. Refrigerating the injection may reduce the pain associated with SC injection.

Meloxicam

NSAID

Acute/chronic

0.2 mg/kg PO, IV, or SC followed by 0.1 mg/kg PO q 24 h

Not for epidural use

Not for CRI

Meperidine

Opioid

Acute

3–5 mg/kg IM, SC q 1–2 h

Not for epidural use

Not for IV use

DEA Schedule II. Also known as pethidine. Do not administer IV due to histamine release. May be painful on IM or SC injection.

Mepivacaine

Local anesthetic

Acute

1–5 mg/kg local infiltration

3–4.5 mg/kg

Not for IV use

Not for IV use. Systemic administration has resulted in severe cardiac and CNS toxicity including death.

Methadone

Opioid

Acute

0.1–1 mg/kg IM, SC, IV q 4–8 h

0.1 mg/kg

0.1–0.2 mg/kg IV followed by 0.12 mg/kg/h IV CRI

DEA Schedule II. Oral bioavailability is limited in dogs.

Morphine

Opioid

Acute

0.5–1 mg/kg IM, SC, or IV (slowly)

Preservative free: 0.1 mg/kg

0.3–0.5 mg/kg IV (slowly) followed by 0.1–1 mg/kg/h IV CRI.

DEA Schedule II. Rapid IV administration causes CNS excitation.

Oxymorphone

Opioid

Acute

0.05–0.2 mg/kg IV, IM, SC q 1–6 h

Preservative free: 0.05–0.1 mg/kg

0.02–0.1 mg/kg followed by 0.01–0.02 mg/kg/h IV CRI ^e,f

No longer commercially available in the US.

Prednisone/Prednisolone

Corticosteroid

Chronic

0.5–1 mg/kg PO q 24 h

Not for epidural use

Not for IV use

Do not use concurrently with NSAIDs.

Pregabalin

GABA receptor agonist

Chronic

2–5 mg/kg PO q 8–12 h

Not for epidural use

Not for IV use

DEA Schedule IV.

Remifentanil

Opioid

Acute

NA due to extremely short duration of action.

1 mcg/kg IV followed by 0.1–0.3 mcg/kg/minute IV CRI.

DEA Schedule II.

Robenacoxib

NSAID

Acute/chronic

2 mg/kg SC for up to 3 days; 1 mg/kg PO q 24 h

Not for epidural use

Not for IV use

Ropivacaine

Local anesthetic

Acute

2 mg/kg as a local infiltration

0.2–1.65 mg/kg

Not for IV use

Not for IV use. Systemic administration has resulted in severe cardiac and CNS toxicity including death.

Sufentanil

Opioid

Acute

0.5–1 mcg/kg

0.5–1 mcg/kg slow IV followed by 0.5–1 mcg/kg/h IV CRI

DEA Schedule II.

Tramadol

Synthetic opioid

Acute/chronic

4–10 mg/kg PO q 6–8

Not for epidural use

Not for IV use

DEA Schedule IV.

Xylazine

Alpha-2 adrenergic receptor agonist

Acute

0.05–0.5 mg/kg IV, IM, or SC as an adjunctive therapy.

Not for epidural monotherapy

Not for use as CRI

Not suitable for analgesic monotherapy.

^a CRI=constant-rate infusion. ^b GABA=gamma-aminobutyric acid. ^c NMDA=N-methyl-D-aspartate. ^d NK-1=neurokinin-1

^eMathews KA. Small animal practice update on management of pain. Vet Clin North Am. 2008;38(6):1435.

^fSmith LJ, Yu JK, Bjorling DE, Waller K. Effects of hydromorphone or oxymorphone, with or without acepromazine, on preanesthetic sedation, physiologic values, and histamine release in dogs. J Am Vet Med Assoc. 2001;218(7):1101-1105.

^gHerrera Becerra JR, Monteiro ER , Martins LGB, Baier ME, Santos EA, Bianchi SP. Epidural administration of combinations of ropivacaine, morphine and xylazine in bitches undergoing total unilateral mastectomy: a randomized clinical trial. Vet Anesth Analg. 2022;49(1):126-134.

In these topics

Analgesics Used in Animals