Dogs and cats feel pain the same way we do, and it can cause some serious side effects ie fear, depression and increased cortisol flow which creates more inflammation adding to the pain. Pain management is being studied a lot more throroughly in animals, especailly as it pertains to surgery. There are several approaches to manage chronic and acute pain from Western methodology to a more holistic approach
As for surgery vets are finding that preventing pain is a much better option than managing pain after the fact.
Here is one example of what can happen if the body is overwelmed by pain either acute or chronic
The exererpt below is from an article on and the full article can be found at this link from Dr. Marty Becker.
http://www.drmartybecker.com/veterinary-medicine/pet-pain-prevention-better-cure/
WIND UP PHENOMENON Wind-up phenomenon is a very important newly understood concept in pain management. The vast majority of patients experiencing acute pain can be managed with conventional analgesics such as NSAIDS, opioids and local anesthetics but patients whose pain is unmanaged or who present in preexisting pain states may require additional therapy. Many patients stop responding to common analgesic drugs due to spinal cord wind-up. The central nervous system adapts adversely to repetitive pain impulses after prolonged stimulation of nociceptors. This can cause a profound effect the nervous system’s architecture thereby altering pain processing. When spinal neurons are subjected to repeat or high-intensity nociceptive impulses, they become progressively and increasingly excitable even after the stimulus is removed. This condition is known as central sensitization or wind-up phenomenon and leads to nonresponsive or chronic intractable pain. Wind-up is the culmination of two distinct phases of change in the nervous system. First, pain transmitting nerve fiber threshold is reset. This resetting results in hyperalgesia where less and less stimulation is required to initiate pain. In the second phase, nerve fibers that normally carry non painful information are recruited and become part of the pain transmission process. This phase is termed allodynia and results in normally harmless sensations being interpreted as pain. The presence of hyperalgesia and allodynia collectively is considered wind-up phenomenon. This is apparent, for example, in the dachshund with disk disease that cries out in pain when any part of its body is touched, or the cocker spaniel with a chronic ear infection that can no longer tolerate normal petting. This phenomenon highlights the need for preemptive analgesia to treat pain before it begins and at regular intervals post-operatively.
Here is a good link for pain management options eastern and western
http://dogs.lovetoknow.com/wiki/Canine_Pain_Relief
Ideally if a western and eastern/alternative regiment can be combined that is a great way to fight pain and support your pets overall well being .
Here are a few points to try to help alleviate pain in your pets.
Always check with your vet if there is a sudden onset of pain in your pet. Once you have determined the cause then you can decide which modality or combinations there of will be best for your pet .