Many people think of chronic pain in the same way they think of acute pain. However, in reality, there is a world of difference between the two.
Let’s start out with a basic definition of both terms.
Though the pain may be extreme, it is usually short-lived comparatively.
There may be frequent recurrences in cases of chronic pain also.
Chronic Pain Is Not Acute Pain that Lasts a Long Time
This is an important concept to understand. Chronic pain and acute pain are totally different from one another. This point was driven home for me recently when I attended a lecture presented by Dr. William Tranquilli at the 2011 Rhode Island Veterinary Medical Association annual veterinary conference. Dr. Tranquilli spoke at length about pain and various methods of pain control.
Here’s what you need to understand about chronic pain.
Chronic pain is actually associated with a dysfunctional nervous system.
For dogs (and people) that suffer chronic pain, the nervous system is actually not functioning as it should.
Where Does Pain Come From?
The concept of pain is a complicated one. There are actually many different types of pain. There is a maladaptive pain, in which the concepts of normal physiology cannot explain why the pain is present. There is a peripheral pain, which occurs as a result of damage or inflammation to the painful area. There is neuropathic pain, where the pain is due to damaged or entrapped nerves. And there is a central pain, a disturbance in the pain processing pathways that exist in the central nervous system. I mention these not because I think they’re important for the average dog owner to know about but only to demonstrate how complex pain really is.
Traditional thinking about chronic pain blames its existence on damage to tissues.
However, more recent advances are leading us to understand that the severity of pain experienced is not necessarily a function of the amount of pathology present. It is instead based on how the central nervous system processes this pain.
In cases of chronic pain where the central nervous system may actually not be functioning as it would normally, pain may be perceived as much worse than what would be expected based solely on the degree of damage to the tissues involved.
In other words, a dog with arthritis may actually be feeling more pain than we would suspect merely by looking at the changes we are able to see in that dog’s joints.
Interestingly, Dr. Tranquilli also talked about the concept that there may even be a genetic predisposition for chronic pain. Apparently, in people, various genes have been identified as being involved in the appearance of fibromyalgia, a disease which is caused by overactive nerves. In addition, chronic pain has also been associated with many other disease processes in people, including depression.
Treating Chronic Pain in Dogs
Because chronic pain differs so much from acute pain, a different approach to treatment is sometimes necessary as well.
Dogs that are suffering from chronically painful conditions may actually be experiencing abnormally heightened sensitivity to pain. This is a condition known as hyperalgesia. As a result, Dr. Tranquilli believes that medications that can inhibit the central nervous system’s pain response may be helpful for these dogs. He concludes:
“Adjunctive drugs such as gabapentin, amantidine, tramadol and even low dose opioid therapy that target the altered neurobiology of chronic pain can be initiated early on in therapy if base analgesic therapy is considered wanting or later when non drug techniques are becoming less effective.”
In real life, we see conditions that cause chronic pain in our dogs on a regular basis.
Things like arthritis, hip dysplasia, and many other conditions can cause chronic pain for our dogs. With a better understanding of the reasons behind the pain that these dogs feel comes the potential for better, safer and more effective ways to treat them.