Treating Chronic Pain in Dogs

By Jennifer Coates, DVM on May 12, 2014

I have a special interest in geriatric medicine. While roly-poly puppies always brighten up a veterinarian’s day, for me, nothing beats a gray muzzle smiling up at me. The most common condition I have to deal with in my older patients is chronic pain. When the source of that pain cannot be eliminated (think osteoarthritis in multiple joints or some types of cancer), effective pain relief can quite literally be a life-saver.

Because I treat pain so frequently, I have come up with a go-to combination of medications that I reach for unless the dog’s condition demands something different. Most chronic pain patients respond best to what is called “multi-modal” pain relief. In other words, by using several medications that have different mechanisms of action, we can achieve better pain control and reduce the incidence of side effects.

Most dogs that I treat for chronic pain receive some combination of the following:

A Non-Steroidal Anti-Inflammatory (NSAID)

Examples include carprofen, deracoxib, etodolac, firocoxib, and meloxicam.
NSAIDs work by blocking enzymes that promote the production of pro-inflammatory prostaglandins.
Common side effects – decreased appetite
Occasional side effects – vomiting, diarrhea, dark or tarry stools, behavioral changes
Rare side effects – increased water intake, increased urination, pale or yellow gums or skin, incoordination, seizures
Should not be given to dogs who are not eating or have stomach ulcers, major kidney or liver dysfunction, known bleeding disorders, or previously not tolerated NSAIDs well. Stomach protectants, such as famotidine, can be used as a precaution in dogs who have sensitive stomachs.
Do not use in combination with prednisone or other NSAIDs. Ideally 4 to 7 days of “washout” time should be allowed between ending Prednisone or another NSAID and starting an NSAID.

Tramadol

Tramadol acts at the level of the brain, binding to opioid receptors and affecting the reuptake of certain neurotransmitters, which reduces the perception of pain.
Works best for chronic pain when combined with other pain relievers such as NSAIDS, gabapentin, and/or amantadine.
Generally well tolerated, but may cause sedation and/or incoordination. Tastes bitter, hide well in food. Pets may drool if they taste the medication.
Occasional to rare side effects include anxiety, agitation, tremor, poor appetite, vomiting, constipation, or diarrhea.
Best to start with a low dose and increase as needed.

Gabapentin

Gabapentin was developed as an antiseizure medication but is also useful in the treatment of chronic pain. It’s mechanism of action is not fully understood, but it is thought to decrease the release of certain neurotransmitters in the brain that are associated with the sensation of pain.
Works best combined with other pain relievers such as NSAIDS, tramadol, and/or amantadine.
Generally well tolerated, but may cause sedation and/or incoordination.
Best to start with a low dose and increase as needed. Dogs with advanced arthritis and muscle atrophy may have more trouble with coordination, walking, and standing.

Amantadine

Amantadine was developed as an antiviral medication but also is useful in the treatment of chronic pain. It works by partially blocking a receptor within the central nervous system that is associated with pain pathways.
Works best combined with other pain relievers such as NSAIDS, gabapentin, and/or tramadol.
Generally well tolerated, but may cause gastrointestinal effects (diarrhea, gas) or some agitation, both of which tend to resolve as the pet adjusts to the medication.
Use with caution and decrease dose in patients with liver or kidney dysfunction, congestive heart failure, and seizure disorders.

All dogs will not benefit (or even tolerate) any or all of these drugs. But if your dog is in pain, it is certainly worth asking your veterinarian if more can be done to help him or her enjoy their golden years to the fullest extent possible.