Recognizing Pain and Distress in Animals

What follows are signs that you should be aware to help you judge if an animal is in pain.

Signs of Pain

An animal in pain, regardless of species, usually displays one or more of the following signs:

  1. Attraction to the area of pain
  2. Increased skeletal muscle tone
  3. Altered electroencephalogram response
  4. Increased blood pressure and heart rate
  5. Pupillary dilation
  6. Change in the respiratory pattern

Signs of Acute Pain

  1. Protection of the painful part
  2. Vocalization (especially on movement or palpation of the painful part)
  3. Licking
  4. Biting
  5. Scratching or shaking of affected area
  6. Restlessness
  7. Pacing
  8. Sweating
  9. Increased rate of respiration

Signs of Chronic Pain

  1. Limping
  2. Licking of area affected
  3. Licking of other areas if the painful part cannot be reached
  4. Reluctance to move
  5. Loss of appetite
  6. Change in personality
  7. Changes in eye brightness

Species-Specific Signs of Pain

In compiling general guidelines it has become clear that there are species-specific signs of pain, which should be taken into account when making a practical assessment. Such signs are often associated with what is believed to be a painful condition, although no sign can by itself be regarded as diagnostic of pain and may also occur in conditions in which pain is unlikely to be a feature.

Although a comprehensive description of species-specific signs has not been produced, the following notes and comments might be helpful.











Additional Resources and Information



Institute for Laboratory Animal Research (ILAR)

Recognizing Post-Operative Pain in Animals: Assessing the Health and Welfare of Laboratory Animals (AHWLA)

American Association for Laboratory Animal Science (AALAS) Learning Library

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