You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

A table of analgesics available in the UK for the management of pain in veterinary cancer patients - based upon the 3-stage World Health Organisation recommendations for treating human patients

Many of these drugs (especially the NSAIDs) can only be given for short courses which makes them inappropriate for use in the management of the chronic pain associated with cancer. Many of these drugs have side effects and may be contraindicated in certain patients. Selection of the most appropriate treatment must be left to the animal's veterinarian.

 

DRUG	DOSE RATE	COMMENTS
WHO STAGE 1 - NSAIDs alone
Aspirin	Dogs : 10mg/kg body weight twice daily by mouth Cats : 10mg/kg body weight by mouth on alternate days	Contraindicated in patients with dehydration, cardiac disease, hypovolemia or hypotension, liver disease or renal impairment. Use with care in old animals. Care needed when used in cats and some forms are contraindicated for use in cats.
Carprophen	Dogs : 2-4mg/kg body weight by mouth in divided doses for 7 days then 2mg/kg once daily. 4mg/kg as single dose by subcutaneous or intravenous injection. Cats - 4mg/kg body weight single dose by subcutaneous or intravenous injection	Contraindicated in patients with dehydration, cardiac disease, hypovolemia or hypotension, liver disease or renal impairment. Use with care in old animals.
Flunixin	Dogs : 1mg/kg body weight per day for 3 days by mouth or subcutaneous injection.	Contraindicated in patients with dehydration, cardiac disease, hypovolemia or hypotension, liver disease or renal impairment. Use with care in old animals.
Ketoprophen	Dogs : 1 mg/kg body weight by mouth for up to 5 days for acute pain OR 0.25mg/kg body weight once daily by mouth.for up to 30 days for chronic pain OR 2mg/kg body weight for a maximum of 3 days by subcutaneous, intramuscular or intravenous injection Cats : 1mg/kg body weight once daily for up to 5 days by mouth.OR 2mg/kg once daily for up to 3 days by subcutaneous injection	Contraindicated in patients with dehydration, cardiac disease, hypovolemia or hypotension, liver disease or renal impairment. Use with care in old animals.
Meloxicam	Dogs : 200 micrograms/kg body weight as a single dose by mouth - in food or immediately after food, then 100 micrograms once daily OR 200 micrograms/kg body weight single dose by subcutaneous injection	Contraindicated in patients with dehydration, cardiac disease, hypovolemia or hypotension, liver disease or renal impairment. Use with care in old animals.
Phenylbutazone	Dogs : By mouth - 2-20 mg/kg body weight in divided doses for maximum 7 days or 500mg. Then reduce dosage to lowest effective Cats : 2- 8mg 1-2 times daily by mouth for a maximum of 7 days. Then reduce dosage to daily or alternate days.	Contraindicated in patients with dehydration, cardiac disease, hypovolemia or hypotension, liver disease or renal impairment. Use with care in old animals. Coated tablets should not be broken
Tolfenamic acid	Dogs and Cats : 4mg/kg body weight once daily by mouth with food for 3 days. Can repeat after 4 days in dogs but not in cats.OR 4mg/kg by subcutaneous or intramuscular injection - can only be repeated once after 24 hours	Contraindicated in patients with dehydration, cardiac disease, hypovolemia or hypotension, liver disease or renal impairment. Use with care in old animals.
Vedaprofen	Dogs : 500 micrograms/kg body weight once daily with food for a maximum of 28 days	Contraindicated in patients with dehydration, cardiac disease, hypovolemia or hypotension, liver disease or renal impairment. Use with care in old animals.
WHO STAGE 2 - NSAID's with one of the following  "weak" opioids
Codeine phosphate	Dogs : 0.5-2.0mg/kg body weight twice daily by mouth	It is contraindicated in patients with impaired liver function so care is needed in older animals
Pentazocine	Dogs : 1-3mg/kg body weight by intramuscular injection	Only one-tenth the analgesic potency of morphine. Not recommended for use in cats
Pethidine hydrochloride	Cats and Dogs : 3.3mg/kg body weight by intramuscular injection	33%-50% as potent an analgesic as morphine. Care needed when used in older animals as contraindicated in animals with renal impairment
WHO STAGE 3 - one of the following opioids with or without NSAIDs
Morphine sulphate	Dogs: 200 micrograms /kg body weight by subcutaneous or intramuscular injection Cats : 100 micrograms /kg body weight by subcutaneous injection.	Is the drug of choice for use in dogs, and is commonly given to patients with severe pain. In cats low doses cause analgesia but high doses cause excitation
Methadone hydrochloride	Dogs  : 200 micrograms/kg body weight by intramuscular injection	Same analgesic potency as morphine
Buprenorphine	Dogs : 0.006-0.02mg/kg body weight by intramuscular injection every 8 hours Cats 0.006-0.02mg/kg body weight by subcutaneous or intramuscular injection.	10-20 times the analgesic potency of morphine. Analgesia occurs slowly (15 minutes after intravenous injection) and it lasts up to 12 hours, so repeated doses can lead to toxicity. Care is needed in older animals as it has prolonged activity  in patients with impaired liver function
Butorphanol	Dogs : 500 micrograms/kg body weight 2-4 times daily by mouth for up to 14 days  OR  200-300  micrograms/kg body weight by subcutaneous, intramuscular or intravenous injection Cats : 400 micrograms/kg body weight by subcutaneous or intramuscular injection. 100 micrograms/kg body weight by intravenous injection	4-7 times the analgesic potency of morphine.  It is contraindicated in patients with impaired liver function so care is needed in older animals

Updated January 2016