04/04/2023
The connection between pain and behavior.
Give your dog the benefit of the doubt.
If your dog is struggling with behavioral issues - for example, fear - it is worth looking into whether they have underlying pain. Dogs are often in a lot of pain before most of us start to see it. This is true if a troubling behavior starts suddenly and when it has been happening for a long time. Puppies can also experience pain from a very young age.
Think about your own behavior when you are in pain.
Ever experienced tooth pain? How's your behavior then?
Back pain? How's your behavior then?
Headache? How's your behavior then?
Gut pain? How's your behavior then?
How often do we ignore our own pain? How often do others not know we are in pain because we don't show it? That doesn't mean it's not there.
Sometimes, we are told by our vets that there is nothing wrong with our dog, that they are just "quirky" or that when they "skip" with a back leg or do a bunny hop that it's just a "habit" or that a leg shaking is common so it's not showing pain or that something is "common" in a particular breed or just common in dogs.
Well, common does not mean it's normal and fine and that we should ignore it. It's very real.
I have heard many stories of people consulting with a few vets before the dog was properly diagnosed. Yes, there are amazing vets who understand this, but it is not uncommon.
Yet another reason not to purposely use punishment on dogs.
THE BIDIRECTIONAL LINK BETWEEN PAIN AND BEHAVIOUR PROBLEMS
With the publication of landmark of research such as Mills et al. (2020), pain is commonly being considered as a potential factor in “behaviour problems” diagnosed in dogs. Vets, behaviourists, and other professionals are becoming increasingly aware of the effects of pain, and how this may present as fearfulness or aggression (or in other ways) because when a dog is in pain and feeling vulnerable, emotions like fearfulness and irritability can increase (much like in humans).
Before getting onto how distress may influence pain, some of background information is needed. It was previously thought the amount of tissue damage an animal experienced directly correlated to the amount of pain they experienced, this concept was known as “specificity theory” (Moayedi & Davis, 2020). It is now well known that the concept of “specificity theory” is flawed as contextual cues massively impact how we process pain (Wiech et al., 2008). Additionally, some individuals are hypersensitive to pain, there are two broad categories of pain hypersensitivity: allodynia and hyperalgesia.
Allodynia refers to when normally non-painful stimulus elicits a pain response and hyperalgesia refers to when a normally mildly pain eliciting stimulus induces an extreme pain response (Jensen & Finnerup, 2014). See the image below for a comparison of allodynia and hyperalgesia. This type of pain is no less real (we still see exactly the same pain neurocircuitry activating) and can be very distressing for the individual that experiences it. There is also some evidence this type of pain is adaptive from an evolutionary perspective as sensitisation of pain circuitry can reduce predation risk (Crooke et al., 2014).
Pain hypersensitivity has been associated with some medical conditions, especially those that cause nerve damage such as diabetes, however it can also be caused by emotional distress. There is a growing body of research that suggests that hyperalgesia can be caused by chronic stress and emotional trauma (Jennings et al., 2014; Qi et al., 2016) with similar results indicating chronic stress and emotional trauma increase the risk of allodynia development (Dib et al., 2021; Bardin et al., 2009).
So with this in mind, there is strong evidence the link between pain and distress is bidirectional. This has really important implications for practice, as it indicates when we are working with a dog that experiences pain, a pain management plan should consider both medical interventions and interventions that reduce stress or support trauma recovery to help the dog get out of “survival mode” (still ensuring all behavioural interventions are not contraindicated with the medical side of the dog’s pain management/pain recovery plan).
For more on this sign up to Trauma Informed Pet Professionals in May 2023.
Daniel Shaw GMBPsS, CDBC
References:
Bardin, L., Malfetes, N., Newman-Tancredi, A., & Depoortere, R. (2009). Chronic restraint stress induces mechanical and cold allodynia, and enhances inflammatory pain in rat: Relevance to human stress-associated painful pathologies. Behavioural brain research, 205(2), 360-366.
Dib, P., Zhang, Y., Ihnat, M. A., Gallucci, R. M., & Standifer, K. M. (2021). TNF-alpha as an initiator of allodynia and anxiety-like behaviors in a preclinical model of PTSD and comorbid pain. Frontiers in Psychiatry, 12, 721999.
Crook, R. J., Dickson, K., Hanlon, R. T., & Walters, E. T. (2014). Nociceptive sensitization reduces predation risk. Current Biology, 24(10), 1121-1125.
Jennings, E. M., Okine, B. N., Roche, M., & Finn, D. P. (2014). Stress-induced hyperalgesia. Progress in Neurobiology, 121, 1-18.
Jensen, T. S., & Finnerup, N. B. (2014). Allodynia and hyperalgesia in neuropathic pain: Clinical manifestations and mechanisms. The Lancet Neurology, 13(9), 924-935.
Mills, D. S., Demontigny-Bédard, I., Gruen, M., Klinck, M. P., McPeake, K. J., Barcelos, A. M., ... & Levine, E. (2020). Pain and problem behavior in cats and dogs. Animals, 10(2), 318.
Moayedi, M., & Davis, K. D. (2013). Theories of pain: from specificity to gate control. Journal of Neurophysiology, 109(1), 5-12.
Qi, J., Chen, C., Meng, Q. X., Wu, Y., Wu, H., & Zhao, T. B. (2016). Crosstalk between activated microglia and neurons in the spinal dorsal horn contributes to stress-induced hyperalgesia. Scientific Reports, 6(1), 1-12.
Wiech, K., Ploner, M., & Tracey, I. (2008). Neurocognitive aspects of pain perception. Trends in cognitive sciences, 12, 306-313.
(Figure reprinted from Lolignier et al., 2015).