Pain Alleviation in Animals

Acute perioperative, traumatic, and disease-related (eg, cancer, pancreatitis, pleuritis, otitis externa) pain is generally treated pharmacologically with one or more analgesics. The optimal drug or drug combinations are determined by the anticipated severity of pain, health status, and availability of drugs for the given species. The more extensive the tissue trauma or disease-induced tissue damage is, the greater need of use of analgesics from more than one drug class (multimodal or balanced analgesia).

Multimodal analgesia maximizes the beneficial analgesic effects of multiple drugs via additive or synergistic interactions while minimizing adverse drug effects by employing lower doses.

A perioperative approach to managing surgically induced pain should begin with the administration of an analgesic prior to surgery (preemptive analgesia) and continue with appropriate analgesia throughout the intraoperative period. Three to five days is a useful guideline for the duration of analgesic treatment after acute surgical pain. Depending on multiple factors (eg, procedure performed, rehabilitation plan, species, breed), some animals require a shorter duration of treatment, whereas other animals require analgesia for longer periods.

Aggressive analgesic treatment of several days’ duration should be tapered rather than stopped abruptly. As-needed dosing schedules are less effective than scheduled analgesic doses to treat pain. As-needed protocols require the animal to demonstrate overt pain behaviors to the extent that they are recognized by the veterinarian and/or owner. Aggressive prevention and management of acute pain often prevents wind-up of the nociceptive pathways, hastens return to normal function, and decreases the risk of developing chronic pain syndromes.

Minimizing stress and anxiety by adding behavior modifiers or mild sedatives (trazodone, gabapentin, alpha₂ adrenergic agonists) when appropriate and ensuring that overall care and husbandry are in accordance with the needs of the animal can also improve pain management. Proper housing conditions, nutritional support, and interaction with other animals and/or humans should be optimal for the given species and breed.

Appropriate analgesia after surgery or trauma allows animals to rest. For example, dogs and cats often sleep but should be arousable after surgery if their pain is controlled. The use of pain as a means of restraint (ie, to prevent the animal from injuring a surgical site) is unethical.

Managing painful and distressed animals requires a combination of good nursing care, nonpharmacologic methods (eg, bandaging, ice packs or heat, physical therapy and acupuncture), and pharmacologic methods.

Acupuncture is a safe, well-tolerated treatment and is shown to decrease pain from inflammation, neuropathy, and cancer, as well as visceral pain.(1,2,3) The nervous system generally mediates effects at the peripheral, spinal, and supraspinal levels. Acupuncture effects include release of endogenous opioids and neurotransmitters and activation of descending pain inhibitory pathways and inflammatory mediators.