Arthritis in Small Animal Medicine

Oct 10, 2023

Arthritis is a blanket term used to refer to any type of inflammation in one or more joints. While there are many possible causes of arthritis (i.e. bacterial or “septic” arthritis; immune mediated; degenerative; traumatic; etc), the type most commonly referred to is osteoarthritis, or degenerative joint disease (DJD). DJD or osteoarthritis is an extremely common condition in dogs and cats as well as in humans, and represents the age associated damage to cartilage and surrounding bone as a result of repetitive stress on the structures.

Degenerative joint disease occur as a consequence of repetitive stress on a joint. While age plays a significant factor in the development of arthritis (due to an increased time to accumulate trauma), other factors also play significant roles. These include obesity (one of the most significant predisposing factors), previous trauma or infection to the joint, damage to ligaments or tendons, and the lifestyle of the animal. Genetic predisposition also plays a significant role. DJD is incredibly common in all species, and it is unusual to find a geriatric animal with no signs of arthritis.

Osteoarthritis may present in a variety of ways depending in the individual animal. Classic signs include lameness or limping, pain when moving joints or handling limbs, and difficulty when standing up from laying down. Other possible signs may include changes in behavior, resentment to being touched, hiding or reduced friendliness, and a change to normal activity levels. Many of these signs overlap significantly with other conditions such as spinal disease, immune mediated conditions, or other systemic illness; as such it is important to not write off concerns as “just arthritis” and have any animal showing signs of pain or discomfort evaluated by a veterinarian. Diagnosis of arthritis is based on the exclusion of other conditions, physical examination, and careful history taking. Remember that most animals hide signs of disease until it is advanced, and so an animal showing signs of arthritis is likely quite uncomfortable.

Management of arthritis may involve aspect of both treatment and prevention, often used in combination with each other. Therapies to help slow the progression of arthritis include regular low-impact exercise (such as walking or swimming), physiotherapy, and the use of nutritional supplements such as fatty acids, glucosamine, chondroitin, and others. Injectable cartilage protecting drugs may also help pain, for example polysulfonated glycosaminoglycans. The most evidence is for the use of omega-3 fatty acids, and so these should be a component of any management strategy. Other therapies, including massage, acupuncture, laser therapy, and other alternative modalities have potential benefits, though less strong evidence for their use. They are unlikely to be detrimental in most cases and may form the basis of a comprehensive management plan. Ensure that any person managing a pet’s arthritis is a licensed veterinarian, technician, or other regulated individual. Humans and animals have very different anatomy and physiology, and therapies for humans may harm dogs and cats.

Medical options for arthritis are very wide ranging. Non steroidal anti-inflammatory drugs (NSAIDs) are amount the most commonly used and efficacious treatments, as they both reduce inflammation and treat pain. Veterinary-labeled NSAIDs should be used to ensure safety in these species. Other pain control options include gabapentin/pregabalin and amantadine (which are pain-killers but do not reduce inflammation), acetaminophen (at careful doses in the right patients), and in some cases, opioids. Tramadol is effective in cats for pain control, but has limited efficacy in dogs and is not a preferred option. Newer drugs such as frunevetmab and bedinvetmab are monoclonal antibodies given as once monthly injections for pain.

It is of crucial importance to note that many human medications for arthritis are not safe in veterinary patients. In particular, NSAIDs marketed for humans such as ibuprofen and naproxen (and acetaminophen in cats) are extremely toxic and should never be given. Aspirin is less toxic, but is a poor pain killer and often causes intestinal bleeding.

In general, animals with arthritis can have a good prognosis if managed appropriately. While this condition can significantly affect quality of life and can be an impetus for end-of-life decisions, this can be mitigated by early and aggressive multi modal management involving rehabilitation, chondroprotection, and multiple pain management strategies.

References

Sanderson RO, Beata C, Flipo RM, Genevois JP, Macias C, Tacke S, Vezzoni A, Innes JF. Systematic review of the management of canine osteoarthritis. Vet Rec. 2009 Apr 4;164(14):418-24. doi: 10.1136/vr.164.14.418. PMID: 19346540.
Doit H, Dean R. Canine osteoarthritis. Vet Rec. 2016 Apr 2;178(14):348. doi: 10.1136/vr.i1801. PMID: 27034303.
Corral MJ, Moyaert H, Fernandes T, Escalada M, Kira S Tena J, Walters RR, Stegemann MR. A prospective, randomized, blinded, placebo-controlled multisite clinical study of bedinvetmab, a canine monoclonal antibody targeting nerve growth factor, in dogs with osteoarthritis. Vet Anaesth Analg. 2021 Nov;48(6):943-955. doi: 10.1016/j.vaa.2021.08.001. Epub 2021 Aug 22. PMID: 34565678.

Author

Matthew Kornya, BSc, DVM, ABVP (Feline) Residency Trained, Resident ACVIM (SAIM)
Consulting Editor

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