Understanding chronic pain
Eighty per cent of dogs over eight years of age are in pain with arthritis.
Chronic pain - what is it? This was the question asked by veterinary surgeon Louise Clark during her lecture at the London Vet Show today (16 November).
Although we are much better now at treating acute pain, which is the body's protective mechanism for staying alive, the treatment of chronic pain (pain that continues when it should not) is still an issue.
Chronic pain is all about how it makes you feel and the emotional response that is produced and the veterinary surgeon needs to look at the behavioural expression of pain in the animal. In people, chronic pain is associated with anxiety, depression and sleep disorders and it is now thought that dogs also express such pain in a similar way.
Chronic pain can be subdivided into three main categories:
- Neuropathic such as amputations and nerve injuries
- Nociceptive or inflammatory such as chronic inflammation and osteoarthritis
- Generalised mixed pain
Louise pointed out that if we can understand where the pain is coming from and the physiology of the pain, then it will be easier to determine its treatment.
She explained that the most important organ involved in chronic pain is the brain. Pain changes the function and structure on the central nervous system (CNS), so pain is very much in the brain. It is amplified through the CNS and translated into an emotional output.
MRI has identified how physical pain can be highlighted in the brain in the limbic system - it is the limbic system that expresses lack of motivation due to pain.
So when treating chronic pain it is vital to recognise the way the brain is exhibiting the emotional effects of the pain it is detecting.
At the end of her lecture, Louise showed a short video which highlighted how our pets cannot show us or tell us about their pain. She then pointed out that 80 per cent of dogs over eight years of age are in pain with arthritis.
Veterinary practices are being urged to help owners safely dispose of any unused and expired pet medicines - not just antibiotics - during November's Animal Medicines Amnesty. 
