It was barely 10 years ago that I found myself sitting in a scientific conference listening to a veterinary researcher who claimed, "Dogs do not feel pain to the same degree that people do and therefore the idea of assessing and managing pain in dogs is not very important."

The myth that dogs don't feel pain like humans do, or at least, that they don't feel as much of it as we do, is partly the result of a legacy from their evolutionary origins as hunting predators. Canines have inherited an instinct to hide any pain that is caused by injuries or infirmity. In the wild, an animal that is injured or infirm is vulnerable to attack, and there is a survival advantage to act like nothing is wrong even when something most definitely is. Thus our pet dogs still appear to act in a stoic manner. They suppress many of the more obvious signals of pain and injury to protect themselves and their social standing in their pack. They hide their pain to appear to be more in control of the situation, but unfortunately, because of this, it is often difficult for humans to recognize when our dogs are hurting.

Many veterinarians have accepted the idea that dogs have a low sensitivity to pain except for certain "wimpy breeds." This is confirmed by several survey's that have shown that even after surgical operations, such as abdominal procedures and spaying or neutering, approximately half of all vets send the dog home without any to control pain.

Some vets even argue that a little pain is good for an animal that needs to be rested, since it keeps the animals quiet and prevents excessive activity. However, consider the comparable human situation where a woman has had a hysterectomy (basically the same procedure as spaying a dog). Imagine what the response would be if her physician told her that he was not going to prescribe any medication for her since "the pain will be good for you because it will keep you quiet while you are healing."

The research literature is quite clear in showing that pain, especially if it is experienced over a long duration of time, can actually be hazardous to a dog's health. The reason is that pain is a stressor, and in response to the body begins to release a set of stress-related . These affect virtually every system in the body, altering the rate of metabolism, causing neurological responses, causing the heart, thymus glands, adrenal glands and the immune system to go into a high state of activity. If this situation continues long enough these organs may actually become dysfunctional. In addition, the tension that the state of pain-related stress induces can decrease the animal's , cause muscle fatigue and tissue breakdown, and also rob the dog of needed, healing sleep. In the end, the dog is exhausted as well as distressed, and this reduces the body's ability to heal.

Researchers at the University of Wisconsin Veterinary School studied the effects of controlling or managing pain from injuries, illness and surgical procedures in dogs. They concluded that the "benefits include improved respiratory functions, decreasing stress responses surrounding surgery, decreased length of hospitalization, faster recovery to normal mobility, improved rates of healing and even a decreased likelihood of infection after surgery. Almost all studies show people and animals return to normal eating and drinking habits sooner when given relief from pain."

The researchers sum up their results by suggesting that the prevention, early recognition and aggressive of pain and anxiety should be essential to the veterinary care of dogs. They warn us that it is important to be sensitive to the subtle signs of pain in our , because the treatment of pain itself can be healing by reducing the stress that can prolong recovery.

With that in mind, it is important for you to know the signs and symptoms of pain in your dog. You may be a better judge of whether your dog is hurting than your veterinarian simply because there is nothing better than being familiar with an individual dog in order to recognize how its behavior has changed and how it shows pain.

Generally speaking, dogs that are hurting:

usually appear less alert and quieter than normal

may hide to avoid being with other animals or people

may have stiff body movements and show an unwillingness to move

might lie still or assume an abnormal posture to reduce its discomfort

can appear restless and more alert and may start pacing around

show signs of stress, which include panting, shallow breathing, shivering, and the pupils of their eyes may be larger than usual

may stop eating normally

Contrary to what you might expect, dogs will not show increased barking when they are in pain; however, they are more likely to whimper or howl, especially if they are left alone.

A dog who is in pain may engage in unexpected growling if someone approaches, and it may appear to be more aggressive. Part of this might simply be the result of attempts to guard or protect the parts of their body which hurt.

While any of these changes in your dog's behavior may mean that your pet is in pain, some of these symptoms are also things you might see if your dog is , nervous or in poor health. As such, they are early warning signs which should cause you to take your pet in for a proper medical examination.

Remember, the longer your dog is in pain, the longer his recovery may take because of the side effects of pain-related stress. However, the good news is that veterinarians now have many more good and effective ways to manage and control pain in your dog.

Stanley Coren is the author of many books, including Born to Bark, The Modern Dog, How Dogs Think, and more.

Copyright SC Psychological Enterprises Ltd. May not be reprinted or reposted without permission.