I listened to a fascinating Facebook Live talk last night by Professor Daniel Mills from University of Lincoln, run by Canine Arthritis Management (CAM) discussing his research¹ on the link between pain and behaviour in dogs. Shockingly it was found that approximately 80% of behavioural issues in dogs are due to pain. It got me thinking about what that figure might be for horses, mules and donkeys, the latter being especially interesting due to their renowned stoicism.
I would predict it to be similarly high. Equids in general have marked behavioural differences to dogs due to their evolution as a prey species making them less likely to show weakness when in pain as it makes them vulnerable to predators. This means that when they do show behavioural changes, it is probably at an advanced stage of pain, especially when they have progressed beyond subtle indicators (for example, facial tension) to more overt signs such as severe avoidance behaviour and aggression (for example, napping, bucking, biting).
It was interesting to hear from Professor Mills that even veterinarian clinicians can often dismiss unexplained behaviour as insignificant or a breed trait and that an animal can even hide their behaviour whilst stressed, such as during a veterinary examination, impeding diagnosis. There is also the prevalence of under-reporting, which can limit recognition of pain and suboptimal welfare, and often older animals might have learned to suppress signs. Many owners might mistakenly and anthropomorphically dismiss some behaviours as ‘naughty’ or ‘stubborn’, just plain odd or not worth exploring.
However, once pain is identified, we are very fortunate in the UK and other developed countries that we have access to an array of essential medicines and evidence-based treatments to combat it, a luxury that many low income countries are not afforded. My own dog, who has advanced osteoarthritis and hip dysplasia (hence my engagement with the fantastic organisation CAM) is on a multitude of medications to manage different types of pain and inflammation, and gets regular hydrotherapy, laser therapy, acupuncture and physiotherapy treatments.
Even so, I am mindful that what he has is incurable and I am just doing all I can to prolong his quality of life. I am aware that, despite the various interventions, he is not ‘free’ from pain, as per the Five Freedoms model of welfare assessment, but that taking proactive steps to reduce and manage his pain enables me to positively improve his emotional state. Just one reason why I favour the Five Domains model of welfare assessment over the Five Freedoms, as a more realistic, holistic and achievable model for owners and practitioners to assess an animal’s quality of life by weighing up the balance of positive and negative life experiences and taking incremental steps to tip that balance towards the positive.
On my dog’s bad days, it is incredibly distressing to be unable to add anything else to the mix to help relieve his pain and to question whether negative affective states are beginning to dominate. I look back on the early behavioural signs of pain he showed and feel guilty that I missed their significance. Things like reluctance to jump in the car, panting a lot even at rest, sitting down on walks, lead reactivity towards other dogs. Professor Mill’s study found that even things like noise sensitivity, hypervigilance, resource-guarding, attention seeking ‘clingy’ behaviour, repetitive or compulsive behaviour and difficulty learning new things could stem from pain association.
It is therefore clear that we should adhere to the precautionary principle and assume that any behavioural change might be pain related, even if we think we have exhausted pathology. Sometimes, a trial of analgesics can help confirm pain even where clinical signs are absent. Treatment should also account for managing other negative affective states associated with pain, such as fear, anxiety and frustration. Whilst this may not necessarily help identify the underlying cause, treating potential pain first rather than focusing on trying to ‘fix’ the problem behaviour prevents further deterioration of welfare whilst investigations can be carried out. Further research into this prevailing area will hopefully go a long way towards increasing awareness of animal behaviour and diminish situations whereby animals in pain are ignored or dismissed. For the sake of those who cannot speak up themselves, we must ask, continue asking, listening and learning.
¹Mills, D.S.; Demontigny-Bédard, I.; Gruen, M.; Klinck, M.P.; McPeake, K.J.; Barcelos, A.M.; Hewison, L.; Van Haevermaet, H.; Denenberg, S.; Hauser, H.; Koch, C.; Ballantyne, K.; Wilson, C.; Mathkari, C.V.; Pounder, J.; Garcia, E.; Darder, P.; Fatjó, J.; Levine, E. Pain and Problem Behavior in Cats and Dogs. Animals 2020, 10, 318.