Introduction

Why control pain?

• It causes suffering. The primary duty of veterinary surgeons is to relieve suffering of animals in their care.
• It causes anorexia, catabolism and a stress response. These all result in delayed wound healing.
• It results in prolonged recoveries, longer recumbencies and a greater risk of post-operative complications.
• It can cause ineffective ventilation leading to hypoxia or acidosis.
• It may lead to self-mutilation and interference with wounds.
• It may result in chronic pain.

Considerations of providing analgesia

• The following signs may indicate the dog is in pain Pain: assessment :
  • Anorexia.
  • Dullness and depression.
  • Whining or howling.
  • Restlessness, being unable to settle, or sitting in unnatural positions.
  • Self-mutilation or chewing at wounded area.
  • Tachypnea, tachycardia, hypertension.
  • Aggression or unresponsiveness.
  • Resentment of gentle palpation of wound.
• An injury or surgical procedure that would be painful in a human can be assumed to be painful in a dog. If in doubt, administer a moderate dose of analgesic and assess response.
• Pain is much more difficult to control once it is established due to a combination of peripheral and central hypersensitivity ('wind-up'). Therefore post-surgical pain can be minimized by preventing the nociceptive input from entering the spinal cord that facilitates this wind-up mechanism. This can be achieved by the use of pre-emptive analgesia Pain: management.
• The use of balanced analgesia, ie combining more than one class of analgesic agent, eg opioid + NSAID reduces the total amount of any one analgesic required and thus reduces the risk of unwanted side effects.

Analgesic drugs

Further Reading

Publications

Refereed papers

• Recent references from PubMed and VetMedResource.
• Hansen B (2008) Analgesia for the critically ill dog or cat: an update. Vet Clin North Am Small Anim Pract 38 (6), 1353-1363 PubMed.
• Mathews K A (2008) Pain management for the pregnant, lactating, and neonatal to pediatric cat and dog. Vet Clin North Am Small Anim Pract 38 (6), 1291-1308 PubMed.
• Woodward T M (2008) Pain management and regional anesthesia for the dental patient. Top Companion Anim Med 23 (2), 106-114 PubMed.
• Capner C A, Lascelles B D, Waterman-Pearson A E (1999) Current British veterinary attitudes to perioperative analgesia for dogs.​ Vet Rec 145 (4), 95-99 PubMed.
• Carroll G L (1999) Analgesics and pain. Vet Clin North Am Small Anim Pract 29 (3), 701-717 PubMed.
• Johnson C (1999) Chemical restraint in the dog and cat. In Practice 21 (3), 111-118 VetMedResource.
• Taylor P M (1999) Newer analgesics. Nonsteroid antiinflammatory drugs, opioids, and combinations. Vet Clin North Am Small Anim Pract 29 (3), 719-735 PubMed.
• Torske K E, Dyson D H, Pettifer G (1998) End-tidal halothane concentration and post operative analgesia requirements in dogs - a comparison between intravenous oxymorphone and epidural bupivicaine alone and in combination with oxymorphone. Can Vet J 39 (6), 361-369 PubMed.

Other sources of information

• American College of Veterinary Anesthesiologists' (1998) Position paper on: The treatment of pain in animals. JAVMA 213 (5), 628-630.