Chronic pain can be a severely debilitating illness. It compromises the overall well being of an animal causing reduced mobility, inappetence, cachexia, lowered immunity, altered behaviour and insomnia. Pain perception is the culmination of multiple physiological processes causing an emotional and behavioural response to noxious or previously non-noxious sensations (allodynia). Pain physiology involves stimulation of both peripheral and central nervous system pathways in combination with inflammatory and metabolic processes.
Many progressive degenerative diseases, including osteoarthritis and neoplasia, neuropathic pain states and trauma, cause chronic pain. Chronic pain is currently a poorly treated clinical syndrome within veterinary practice. This is most likely because assessment of pain, especially chronic pain, can be extremely difficult. Animals often become withdrawn, less active or unsettled. These subtle clinical signs may be insidious and slow in onset; they are often put down to ‘old age’ by both owners and clinicians. Chronic pain states can however be well controlled with an effective clinical pain management strategy.
Good pain management can see the return of a good quality of life for the animal, a return of normal behaviours such as sleeping through the night, grooming, increased activity (walking, running, jumping onto the owner’s bed, going upstairs) and a happy demeanour. Even if the underlying instigating pathological cause (e.g. tumour) cannot be removed or ‘cured’, a much improved and pain free quality of life can be provided for the animal.
The basis of good pain management is through a fundamental understanding of the complex summation of processes that go on within the body to cause pain perception and a multimodal approach to analgesia therapy available to block these events. Both pharmacological agents and manual therapies can be used synergistically to improve pain control and quality of life. A range of drugs can be given that act at different points along the pain pathway to control pain perception. These along with physiotherapy, hydrotherapy (using an underwater treadmill and swimming pool) or electrotherapy modalities can enhance patient comfort and mobility.
Each patient needs to be assessed individually; therapy protocols are dependent not only on the clinical presentation but also on co-existing medical conditions and treatments, home environment and goal of therapy.