This article is courtesy of DogTime.com.

Decades ago, veterinarians believed that pain helped keep dogs quiet so they could heal faster. In addition, the prevailing thought was that there wasn't any accurate way to know whether a dog was feeling pain or needed relief. Today's veterinarians have ushered in a new way of looking at pain management for your four-legged friend. Many vets now claim that they administer pain medication until there is proof that a dog isn't hurting.
Veterinary medicine has made pain management a top priority. Organizations such as the University of Tennessee College of Veterinary Medicine Center for the Management of Animal Pain, the Colorado State University College of Veterinary Medicine, the Humane Society of the United States, and the Companion Animal Pain Management Consortium are devoting a lot of time and resources to study pain and pain management in animals. These studies have shown that pain relief may be able to speed the recovery process, whether from surgery or injury. Most importantly, pain relief may help your dog live longer because it reduces stress and increases her sense of well-being.
Acute pain is a sudden onslaught as a result of an injury, surgery, or infection and can make your dog extremely uncomfortable and possibly limit her mobility. This pain seldom lingers, usually disappearing when the condition that caused it is treated.
Chronic pain usually develops slowly and is long lasting. Common sources of chronic pain are age-related disorders such as arthritis, but it can also be caused by illnesses such as cancer or bone disease. This pain is the hardest to deal with because it can go on for years, sometimes even for the rest of the dog's life. And because it develops slowly, some dogs learn to tolerate the pain and live with it, making detection difficult.
Since dogs can't tell us in words that they hurt, it's important that you watch them closely if you detect any change in their behavior. Your dog may be in pain if she:
If you suspect your dog is in pain, talk to your veterinarian, who can help you pinpoint the problem and discuss available options. Your vet will need to know about your dog's behavior, activity level, and tolerance for being handled as well as recent changes in her mobility, such as trouble negotiating stairs (if it was never a problem before), or problems getting up or jumping on and off furniture.
Some dogs don't show signs of pain, but that doesn't mean they aren't feeling it. If the injury, illness, or incident sounds painful to you, assume that your dog is in pain and get her to your veterinarian.
The first and most important thing to do is to get you dog a complete physical exam by your veterinarian, including lab and blood tests or X rays if needed. Veterinarians usually recommend physical therapy, drug treatment, or surgery or a combination of any or all. There are simple things you can do at home to help keep your dog comfortable and to monitor her pain level. (Check with your veterinarian first to make sure these won't harm your dog.)
