Pain Assessment in Cats

Pain management in cats has been neglected for a long time when compared to dogs. However, this scenario has been changed in recent years. The difficulty in assessing pain in cats has been identified as one of the justifications for the less common use of analgesics in this species. Accordingly, pain assessment tools specific for cats must be provided.

Considering the challenge of identification and quantification of acute pain in cats, the UNESP-Botucatu Multidimensional Composite Pain Scale (UNESP-Botucatu MCPS) to assess postoperative pain in cats was developed and validated in multiple languages and cultures. This instrument has a numerical criterion which indicates when analgesic intervention is needed (cut-off point for rescue analgesia), which further increases the benefit of using this scale in both clinical practice and research studies.

The English version of the UNESP-Botucatu MCPS to assess postoperative pain in cats has 10 items: posture, comfort, activity, attitude, miscellaneous behaviors, reaction to palpation of the surgical wound, reaction to palpation of the abdomen/flank, blood pressure, appetite and vocalization. Each scale item is ranked numerically (0, 1, 2 and 3), where "0" indicates no change or normal state, and the highest value indicates the most marked change. The system contains clear guidelines for evaluation, including a detailed description of the behaviors that should be observed in each scale item.

In the English version of the UNESP-Botucatu MCPM the items were distributed in three dimensions or subscales: 1) Pain expression, 2) Psychomotor change and 3) Physiological variables. The multidimensional structure of the instrument allows each dimension/subscale to be examined separately. This approach may be of particular value in a research setting, where meticulous information is necessary. Additionally, in cases where there is any technical difficulty in assessing a particular dimension, that subscale may be omitted from the instrument.

The total score, which describes the overall evaluation of pain intensity, is calculated from the sum of the items scores, and ranges from "0" (arbitrary absence of pain) to “30” (maximum pain). The scores may be classified as mild pain (0-8 points), moderate pain (9-21 points) and severe pain (22-30 points). Analgesic intervention is recommended when the score is ≥ 8. Clearly, pain assessment, even with this validated system, still relies on subjective interpretation of behavior. If a clinician considers an animal is in pain when the scoring indicates otherwise, the benefit of the doubt should apply and the animal given intervention analgesia.