It isn’t always easy to determine the degree to which an animal may be hurting; we veterinarians can’t ask our patients, "How bad does it hurt?" Dogs and cats are also very good at hiding their discomfort, particularly when they are in the unfamiliar surroundings of a veterinary clinic.


For these reasons, we often have to rely on owner perception as to a pet’s comfort level or lack thereof.


Veterinarians need to know how bad the pain is so we can prescribe medications and other interventions that have the best chance of relieving the discomfort while minimizing undesirable side effects, and also to monitor the effectiveness of our therapeutic recommendations. There are several ways to quantify pain.

  1. A description that rates pain as absent, mild, moderate, or severe. This has the benefit of being simple, but doesn’t provide for many shades of gray.
  2. A numeric rating where 0 corresponds to no pain and 10 is the worst possible pain.
  3. A visual analogue scale (VAS) that is similar to the numeric rating but is depicted as a 100 millimeter ruler with 0 being no pain and 100 being the worst possible pain.


Personally, I like the visual analog scale. I find that people can get overly concerned about numbers. Using the ruler, an owner just slides a finger back and forth until he or she finds the point that best matches a pet’s condition. Then the veterinarian puts a number to the determination.


Unfortunately, a recent study determined that untrained owners were not very good at using a VAS because they could not recognize signs of pain in their dogs. The scientists found that owners got much better at using a VAS once pain relievers were stopped and they could see the difference in their pet’s behavior when pain was and was not controlled.


This leads me to my favorite method for determining whether or not an animal who is acting "off" is suffering from undiagnosed chronic pain. First, I perform a physical examination and then collect a minimum database (e.g., blood chemistry, complete cell count, a urinalysis, and perhaps other tests depending on a pet’s condition and history) to rule out other conditions and to make sure that my next step will be a safe one. If all looks good, I then prescribe a short course of pain relieving medication — usually a nonsteroidal anti-inflammatory for dogs and buprenorphine for cats. If over the next few days the symptoms that are of concern to the owner disappear or at least are much improved, I have determined that that pain is a major contributing factor and can then decide how best to move forward with diagnosing its source and treating it.


This method of diagnosing pain (I call it an analgesic response test) has the additional benefit of allowing owners to see the differences in their pets’ behavior when they are hurting and when they are not, which makes them more adept at using a VAS to monitor their pets’ comfort level in the future.


Dr. Jennifer Coates



Image: Kim Reinick / Shutterstock



Last reviewed on July 26, 2015.