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Personality and Pain in Animal End of Life Care

Why it is so important to treat each animal as an individual.

How Ethology Can Help Improve End of Life Care for Animal Patients: Part 1 in a 3 Part Series

Pain is arguably the most important clinical and ethical issue in end of life care for companion animals. Research suggests that many companion animals—perhaps numbering in the millions—are not being treated for pain or are being treated inadequately. [i] A significant portion of missed diagnoses, misdiagnoses, undertreatment, and overtreatment likely can be tied to incorrect behavioral assessments, particularly on the part of pet owners but also, perhaps, on the part of veterinarians.

Jessica Pierce
The author's dog, Maya
Source: Jessica Pierce

Pain is a quintessentially personal experience. Indeed, the most common medical definition of pain is “what the person says it is.” A large body of research has explored how the experience and expression of pain can be influenced by gender, age, past experiences, and cognitive priming. Even individual personality can influence how people experience and express pain. For example, people who rate high on “extraversion” are more likely to express their experience of pain yet may, at the same time, experience pain less intensely than introverted individuals. People who score high on “neuroticism” have higher emotional stress responses to pain than those who score low. [ii] A similar dynamic appears to be at work in nonhuman animals, with individual personality shaping the experience and expression of pain. (Personality can be understood as individual differences in behavior that remain stable over time.) This has important implications for the assessment and effective treatment of animal pain.

Although research into pain and personality in nonhuman animals is still in its early stages, initial results are intriguing. In a 2014 study, Ijichi et al. found preliminary evidence that behavioral indicators of pain in horses may not accurately indicate the level of tissue damage, and that horses’ behavioral response to pain varied in relation to personality. [iii] Lush and Ijichi conducted a similar study in dogs in 2018, using the Monash Canine Personality Questionnaire—Revised[iv] to measure personality and the Short Form Glasgow Composite Measure Pain Scale to measure pain.[v] They found “noticeable individual variation in both behavioral and physiological responses to pain triggered by the same procedure.” [vi (p. 66)]

They also found that behavioral indicators did not correlate with physiological responses and concluded that “behavior may not indicate when an animal was experiencing poor welfare and that individuals respond differently to the same procedure.” Extravert animals scored higher for behavioral expression of pain; more introverted subjects were less likely to exhibit pain-related behaviors. Although the actual pain response may have been the same, the behavioral expression was different. We may thus be more likely to underestimate, and also under-treat, the pain experienced by an introverted animal patient. (In humans, introverts are also less likely to adopt active coping responses. Might the same be true in other animals?)

It has long been assumed that observable signs of pain, such as those measured in pain scales like Colorado State University’s pain scales for dogs (chronic and acute) and cats (acute) are reliable indicators not only of the presence of pain but also of the severity of pain being experienced. Such behavior-based scales are used to identify whether analgesic drugs are helping and at what dosage. The welfare implications of incorrect assessments of pain are obvious: if we underestimate, pain may not be treated effectively; if we overestimate, we may use too high an analgesic dosing, leading to adverse effects, and may also possibly resort to euthanasia prematurely. [vii]

The emerging science of animal personality is vitally important to end of life care, not only in accurately assessing pain but in monitoring how patients respond to treatments, how quality of life may be impacted by disease or lost mobility, and so on. The better pet owners and veterinarians understand each individual animal, the more effectively they will be able to tailor care to that individual’s needs. Several good personality assessment tools for dogs and cats are available online.

Brian Hare’s Dognition Assessment Tool and Amanda Jones’ Dog Personality Questionnaire are two good validated tools for assessing dog personality. Research into cat personality lags behind dog personality research, and we are still waiting for validated tools, but Litchfield et al.'s “The ‘Feline Five’: An exploration of personality in pet cats (Felis catus)” provides important groundwork and validated tools will undoubtedly be available soon. A number of unvalidated cat personality are available (for example here); these can still be useful because they encourage cat owners to observe their animal more closely.

These tools could be used by owners to help build a base of knowledge about canine or feline behavior in general and might nurture a style of close observation and attunement.


[i] Simon BT, Scallan EM, Carroll G, Steagall PV. The lack of analgesic use (oligoanalgesia) in small animal practice. Journal of Small Animal Practice 2017. DOI: 10.1111/jsap.12717.

[ii] Soriano J, Monsalve V, Gómez-Carretero P, Ibañez E. Vulnerable personality profile in patients with chronic pain: Relationship with coping, quality of life and adaptation to disease. International Journal of Psychological Research 2012; 5:42-51.

[iii] Ijichi C, Collins L, Elwood R. Pain expression is linked to personality in horses. Applied Animal Behaviour Science 2014; 152: 38-43.

[iv] Ley JM, Bennettt, PC, Coleman, GJ. A refinement and validation of the Monash Canine Personality Questionnaire (MCPQ). Applied Animal Behaviour Science 2009; 116, 220-227.

[v] Reid J, Nolan A, Hughes JML, Lascelles D, Pawson P, Scott EM. Development of the short form Glasgow Composite Measure Pain Scale (CMPS-SF) and derivation of an analgesic intervention score. Animal Welfare 2007; 16, 97-104.

[vi] Lush J and Ijichi C. A preliminary investigation into personality and pain in dogs. Journal of Veterinary Behavior 2018; 24, 62-68.

[vii] Ashley, H, Waterman-Pearson, AE, Whay, HR. Behavioural assessment of pain in horses and donkeys: applications to clinical practice and future studies. Equine Veterinary Journal 2005; 565-575.