That's why Sheilah Robertson, BVMS, PhD, MCVS, CVA, DACVA, DECVA, former professor of anesthesia and pain management at the University of Florida and current assistant director of the American Veterinary Medical Association's (AVMA) animal welfare division, says it's so important for veterinarians to take time to diagnose pain in cats. And her advice is pretty simple: Look for it, recognize it and measure it.
Currently there's no gold standard for assessing pain in cats, although uniform scales to objectively measure pain are being developed and validated. But in the meantime, it's important for veterinarians to observe feline behavior for clues and to be able to recognize the difference between stress or fear and pain, particularly when it comes to acutely painful conditions.
Robertson states that part of the observation process not only involves keeping an eye out for abnormal feline behavior, such as maintaining a tense, crouched posture or showing difficulty getting into a comfortable position, but also looking for signs of normal behavior, such as stretching or playfully engaging with caregivers. "If a cat is trying to retreat or hide, I'd suspect that cat was in pain and take a closer look," Robertson says.
In general, key indicators of acute pain in cats include changes in posture, position in the cage, activity level, attitude, vocalization, appetite, facial expression and reaction to palpation. Researchers working with mice and rabbits have also identified what can be described as a "pain face," which in cats may include noticeable changes in the eyes, ears and whiskers. Robertson also points out that observing a cat before a painful procedure may yield important clues to the animal's typical demeanor and behaviors, giving the veterinarian a better indication of whether the cat is comfortable after the procedure or if medical intervention is necessary.
What about chronic pain?
While most cats will likely be exposed to an acutely painful procedure, such as surgery, at some point in their lives, it's not an everyday occurrence. But for some cats, chronic pain can be. From degenerative joint disease to cancer, certain conditions can negatively affect a cat's behavior and activity level and, as such, managing chronic pain has become a much greater concern for today's pet owners and veterinarians.
Degenerative joint disease is one of the most common sources of chronic pain in cats but it can also be one of the more difficult conditions to accurately assess. Although pet owners may notice subtle signs of their cat's discomfort at home, such as reluctance to jump or a slower, stiffer gait, it can be tricky for veterinarians to make a clinical assessment based on examination alone. "Cats are smaller and have a natural agility," Robertson says. "It can be difficult to elicit pain in cats or even perform a physical exam at all. They often don't give as much information as dogs."
Changes in the cat's elimination habits should also be part of the discussion. Many cats who experience chronic pain will avoid covering their urine or feces with litter, or may refuse to climb into a litter box altogether. What some pet owners may confuse as inappropriate urination may actually be a sign that the cat is experiencing pain due to degenerative joint disease or another chronic condition.
Assessing quality of life
Robertson points out that in humans, pain is self-reporting—we state how we feel. But in animals, pain is what the pet owner or veterinarian says it is. The same is true for quality of life. Quality of life in pets is relative and often measured by the amount of pain we believe the animal is in. But pain isn't the only factor to be considered.
In a study conducted by B. Duncan X. Lascelles, BSc, BVSc, PhD, DECVS, DACVS, professor of small animal surgery at North Carolina State University, it was hypothesized that quality of life in cats was predominantly linked to mobility. However, 60 percent of pet owners in the study reported that habits such as engaging in play or being receptive to petting were of far greater importance in assessing their pet's quality of life than mobility alone.
Based on the results of studies such as this, Robertson emphasizes the importance of managing chronic pain through environmental enrichment as well as traditional medical intervention in order to improve a cat's quality of life. A stimulus-rich environment that includes playing and petting can prove to be a powerful distraction to chronic pain, Robertson states. And that can make a huge difference.
"Cats sitting in a barren environment will focus on the pain," she says. "But in a highly enriched environment, they will focus on things other than the pain."