Advancements in Pain Management

Five years ago, my Lab-greyhound ruptured ligaments in both knees. The required surgery cut off the top of his tibia and screwed it into a new position, changing the knee geometry. The surgeon allowed me to watch. I saw the saws. I heard the drills. I viewed the damage inside the joint on a TV screen. Even now, my dog’s pain haunts me. He received pain help in the hospital and came home with pain pills, but he still hurt. With jumping onto the bed out of the question, we slept on the floor. Or tried to. I remember counting the seconds he laid still. During the worst pain, he moved every 90 seconds.

THEN AND NOW

Historically, some veterinarians and pet owners believed animals didn’t feel pain or that they experienced it differently. Some considered pain good because it kept animals still and allowed them to heal.

“Now we know that is complete and utter baloney,” says Robin Downing, DVM, who is certified in veterinary acupuncture and canine rehabilitation and is one of only a handful of veterinarians credentialed in pain management by a human medical board.

The truth is that dogs and cats have neural pathways similar to our own. They experience pain like we do. Research shows that treating pain lowers the body’s stress and aids in healing, so pain control is fundamental to quality care. In September 2007, the American Animal Hospital Association and the American Association of Feline Practitioners published the first-ever veterinary guidelines for pain management.

HOW MUCH DOES IT HURT?

The common 1–10 pain scale addresses self-reported pain. But, like pediatricians, veterinarians report pain by proxy because pets obviously can’t tell us how much they hurt. “Simple numeric scales don’t work particularly well when you’re reporting someone else’s pain,” explains Bonnie Wright, DVM, a board-certified veterinary anesthesiologist from Colorado State University’s (CSU) Center for Comparative and Integrative Pain Medicine.

Instead, she says veterinarians use a combination of species-specific behaviors, noting, for instance, if the pet seems inwardly focused or interested in its surroundings. They look at facial expression and body posture. They feel the pet’s entire body, checking for physical indicators of tension or pain.

Dr. Downing says veterinarians ultimately ask, “If I was having this procedure done, how painful would I expect it to be?”

Relatively speaking, dental extractions hurt more than routine dental cleanings. Spaying a female hurts more than neutering a male because it requires cutting the abdominal wall. Surgical removal of a tumor from the abdomen or chest hurts worse. Surgical repair of a fracture or other orthopedic surgery is still more painful. Surgical limb amputation or eye removal comes next. Finally, trauma—such as from being hit by a car—hurts the most.

Chronic pain is also a problem. Both chronic pain and untreated acute pain can “wind up” the pet’s nervous system. Those neurologic pathways become overactive, sending constant pain messages to the brain.

PAIN CONTROL OPTIONS

Pain signals move from the source of trauma to the spinal cord, then up to the brain. Anesthesia makes pets unconscious so they cannot perceive the pain, but the signals still reach the brain. Analgesia, on the other hand, addresses pain in other ways.

Early on, the available analgesic drugs came from human medicine. But in 1997, the first medication designed to manage the chronic pain of osteoarthritis in dogs was introduced, spawning a host of nonsteroidal anti-inflammatory drugs (NSAIDs) for pets.

"Never give your pet any pain medication without first checking with your veterinarian."

Dr. Downing also stresses the importance of opioid drugs (narcotics) in pain control. She calls morphine “the gold standard” and explains that nothing is more effective. “There are drugs that are more potent, meaning you can use a smaller amount to get the same effect,” she says, “but more potent doesn’t translate into better.”

Other drugs called alpha-2 agonists block pain receptors in the spinal cord so that signals never reach the brain.

Local anesthetics, such as what dentists use before filling a cavity, block signals at the site of pain.

“When we’re talking about acute pain, like from surgery,” Dr. Downing explains, “we would leverage all four classes of drugs to our advantage.”

And those are just the drug options. Narda Robinson, MS, DO, DVM, holds two certifications in medical acupuncture and works with Dr. Wright at CSU’s pain center. She uses herbal and nutritional solutions as well as other methods such as low-level laser therapy and massage.

Integrative pain control methods combine drug and nondrug solutions. These methods can be helpful for pet owners who feel discouraged when one drug doesn’t work.

“Owners are critical in assessing pain. It helps us determine how to treat our patients,” Dr. Wright says. “There are a huge number of options. We don’t just say, ‘We tried X, and it didn’t work, so we’re done.’”

A NEW AGE

Dr. Downing sees the excitement about pain management building and encourages pet owners to discuss options with their veterinarian. She sees these ideas spreading as she travels the world teaching practitioners how to control their patients’ pain. “Once you witness a pet who has tremendous pain and you have relieved that pain in a meaningful way,” she says, “you can’t unlearn the experience.”

OUT OF THE ORDINARY

If your pet has undergone surgery or has been injured, you can assume he will experience pain. However, pain in pets isn’t always obvious. Here are some subtle and not-so-subtle signs to watch for:

• Apprehension or aggression
• Excessive scratching, licking, or rubbing at an area
• Guarding a limb or part of the body
• Hiding
• Limping or stiff movement
• Reduced interest in food or loss of appetite
• Reduced interest in people or surroundings
• Reluctance to move
• Not wanting to be picked up or held
• Sitting or lying in awkward or unusual positions
• Sleeping more than normal
• Sleeplessness or restlessness
• Unusual vocalizations or lack of normal vocalizations

Check with your veterinarian if you think your pet may be in pain.

PAIN MANAGEMENT

• Helps pets feel better
• Helps pets heal faster
• Reduces pets’ stress
• Could help pets live longer