As veterinary medicine improves and cats live longer, they experience more complications associated with old age, including osteoarthritis (OA), a progressive degenerative joint disease. The median age of cats with OA is 10.2 years,1 and approximately 90% of those over 12 have been found to have OA.2
In an interview with dvm360®, Elizabeth Colleran, DVM, DABVP, medical director at Chico Hospital for Cats in Chico, California, offered veterinarians and clients tips for detecting and managing the disease in cats.
Subtle signs of feline OA
According to Colleran, identifying osteoarthritis can be more difficult in cats than in dogs. Cats are secretive, she says, because hiding their emotions is to their advantage. As “solitary hunters, they don’t have [a] great repertoire of emotional signs on their face...but they do show what they think and how they feel.”
One should look for “a cat whose lifestyle [has] changed,” she explained; for instance, “a cat that used to sleep with the owner... [but] isn’t sleeping with the owner anymore,” that “used to climb up to a high point on a cat tree...[but] doesn’t do that anymore,” or even a cat that is “sleeping more than usual.”
At the April 2022 Fetch dvm360® conference, Colleran mentioned other signs of OA: avoidance of other household members, increased grumpiness, decreased grooming, restlessness, changes in elimination behavior, clumsiness, and reluctance to jump.3
Pet parents can also use the Feline Musculoskeletal Pain Index, a validated pain score, to check their pets more closely. The Index asks questions about specific indicators of OA that reveal the intensity of a cat’s pain.
A visual assessment of the cat’s gait is important, but the environment must
be carefully controlled. According to Colleran, a quiet, low-stress atmosphere is essential, and the cat should be given time to acclimate to the room. The veterinarian should then gently palpate the joints, even though cats not experiencing joint pain will also be averse to this.
Because OA is complex and usually affects various joints, it can be challenging to stage. Staging is best accomplished by examining the overall impact on the cat. Based on activity and mobility, OA stages are as follows.
- Stage 1: Early signs of activity impairment
- Stage 2: Intermittent signs of activity impairment
- Stage 3: Obvious activity impairment and some decrease in mobility
- Stage 4: Loss of mobility with significant pain3
Multimodal approaches to chronic feline pain
When it comes to addressing the disease, it’s important to tell clients that it can’t be treated, only managed to improve mobility and quality of life. A multimodal approach is the most beneficial, Colleran pointed out, because it combines traditional medication, adjunctive therapies, and environmental modification.
Slow-motion footage to detect OA
Because cats become stressed when away from their territory or surrounded by strangers, it can be difficult to accurately assess their physical and emotional condition at the clinic. But clients can use their phones to record pet movements in slow motion at home, then play them back to see whether those movements are indicative of OA.
“One of the most important things is that cats move so quickly. [When they’re] jumping off a counter, it’s really hard to see the details. If you use the slow-[motion option] on a cell phone, you can actually capture the real motion,” said Elizabeth Colleran, DVM (feline practice). “And you can get a sense of whether the cat is hesitating before jumping or...sort of sliding down the counter to avoid the distance [and] impact. So you get the real details of a really fast- moving object.”
On the pharmacological side, nonsteroidal anti-inflammatory drugs can be used. “There are also some really helpful adjunctive therapies, like laser therapy [and] acupuncture, she said. “Assisi Loop is a favorite of mine because the cats don’t mind it at all,” she added, “and then there are...supplements like omega-3 fatty acids.”
Environmental modification includes making the cat’s space more comfortable so that it can get around more easily and providing it with a warm bed to soothe its joints.
“Environmental modification means that we’re changing the environment to accommodate...something that’s going on with the cat. For example...a lot of my clients will build stairs or ramps for the cats to get up to really high places where they like to sit and watch the world go by or watch the birds outside.”
What's new in feline pain treatment?
At the 2022 convention of the American Veterinary Medical Association,4 Alonso Guedes, DVM, PhD, an associate professor of anesthesia at the University of Minnesota College of Veterinary Medicine, talked about the “newest kid[s] on the block”: anti-nerve growth factor monoclonal antibodies.
Guedes explained that nerve growth factor (NGF) is synthesized and active on many types of cells: various cells secrete—and are affected by—it. NGF signaling is upregulated during the chronic inflammation associated with OA, which results in central and peripheral sensitization and hyperalgesia. In patients with OA, the secretion of NGF increases, sensitizing the periphery and central terminal of the neurons in the spinal cord.
“The NGF also will activate immune cells, and these...cells will then secrete their mediators, [which]...will then amplify inflammation...so it seems like a good idea...[to use] a nerve growth factor neutralizing antibody to block NGF's many effects, and then the nervous system is able to return to its normal [state]. It is [a] pretty nice concept,” Guedes added.
- Bennett D, Zainal Ariffin SM, Johnston P. Osteoarthritis in the cat: 1. how common is it and how easy to recognise? J Feline Med Surg. 2012;14(1):65-75. doi:10.1177/1098612X11432828
- Yeowell G, Burns D, Fatoye F, Gebrye T, Wright A, Mwacalimba K, et al. Indicators of health-related quality of life in cats with degenerative joint disease: systematic review and proposal of a conceptual framework. Front Vet Sci. 2021;8:582148. doi:10.3389/fvets.2021.582148
- Colleran E. Cats don’t limp: chronic pain in the senior cat. Presented at: Fetch dvm360® conference; April 22-24, 2022; Charlotte, NC.
- Guedes A. New advances in chronic pain management in cats. Presented at: American Veterinary Medical Association Convention; July 29-August 2, 2022; Philadelphia, PA.