Physical pain involves a complicated series of physiochemical responses leading to the perception of an unpleasant sensation which serves to protect the body. Pain elicits motor actions to move away from a noxious stimulus to avoid injury. It may arise from the actual tissue injury and (inflammation) or from damage to a portion of the nervous system. Inflammation serves to remove the injurious stimuli (pathogens, damaged cells, etc.) and initiate the healing process. During the inflammatory process, blood vessels dilate to facilitate the mobilization of healing factors to the injured site (e.g. white blood cells, plasma). Although the influx of these mediators is necessary in the healing process, the swelling that ensues may cause pain and could put pressure on nearby healthy tissue. Therefore, it is often important to reduce inflammation in order to alleviate pain.
Acute vs. Chronic Pain
Pain can range from mild and occasional to severe and constant.
- Acute pain arises from sudden stimulus such as surgery or trauma (e.g. burn, cut, broken bone) and is usually sharp in quality. It serves as a warning of disease or a threat to the body. In most cases, acute pain disappears when the underlying cause of the pain has been treated. Unrelieved acute pain, however, might lead to chronic pain.
- Chronic pain may persist despite an injury being healed. The pain signals can remain in the nervous system for weeks, months or years. Chronic pain might have originated with an initial trauma/injury or infection but could also be caused by the ongoing destruction and healing of tissue which actually become the illness. There might be no known cure for the disease that is causing the chronic pain.
Pain associated with neurological disease is often due to inflammation of the nerve roots, meninges, or disks, not the spinal cord itself. A thorough neurological examination is important since many signs of pain that appear neurological may actually be orthopedic or visceral. For example:
- polyarthritis could appear to be cervical spinal pain.
- panosteitis may resemble lumbar spinal pain.
- certain abscesses of the jaw or bone could be mistaken for head pain.
- pain from cruciate ligament ruptures often show similar signs as limb paresis.
Pain may also be referred, in that the discomfort is felt away from the actual area of irritation. For example:
- neck pain may be due to an increase in intracranial pressure.
- back pain may initially cause abdominal tension.
The following list includes some of the more common neurological diseases associated with pain and is not all-inclusive.
- brain swelling
- herniated disk
- vertebral infections or tumors
- vertebral fractures or subluxations / luxations
- nerve root or peripheral nerve tumor
- inflammation (neuritis)
- myalgia (myositis)
This information is meant to be a guide and not a substitute for veterinary care.
Always follow the instructions provided by your veterinarian.