June 20, 2025, 4:11 pm | Read time: 4 minutes
Cats are often considered masters of disguise, especially when it comes to hiding pain. However, a study shows that being overweight can have various repercussions for cats—particularly affecting their joints.
Osteoarthritis–a chronic joint wear and tear–is common in older cats. For a long time, it was unclear what risk factors played a role. While obesity is a confirmed factor for arthritis in humans, this had not been clearly proven in cats. A study has now addressed this topic, filling a gap in veterinary medicine knowledge.
Study Finds Biomarkers and Risk Factors for Arthritis in Cats
Osteoarthritis is a common, age-related joint disease in cats, whose development is not yet fully understood. It is known that many cats are affected on both sides–such as in the hips, elbows, or knees–indicating systemic causes. While obesity is a clear risk factor for arthritis in human medicine, this was unclear or unconfirmed in cats.
Previous studies showed partly contradictory results, partly due to inaccurate diagnostic methods like X-rays or insufficient assessment of body fat. Additionally, newer research suggests that so-called adipokines–hormones produced by fat tissue such as leptin or adiponectin–and the growth factor IGF-1 could play a role in the development of arthritis.
A research team from the Swedish University of Agricultural Sciences (SLU) in Uppsala, led by Cecilia Ley, aims to provide more clarity. The groundbreaking work was published in the journal “BMC Veterinary Research” (2025).
Seventy-two domestic cats were examined using whole-body computed tomography (CT) to determine the relationships between body fat, body size, and the extent of osteoarthritis (OA). Additionally, the researchers analyzed blood samples for the hormones leptin, adiponectin, and IGF-1–all potential markers for metabolic joint diseases. The goal was to better understand which animals are particularly at risk and how arthritis can be detected early.
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Large and Heavy Cats More Often Affected by Arthritis
Ninety-four percent of the cats showed signs of arthritis in the CT, most commonly in the hip, elbow, knee, and carpal joints. Overweight cats had significantly higher overall arthritis scores than lean ones, and particularly larger overweight cats showed much higher scores than smaller, lean ones.
A linear regression analysis also revealed: The older and heavier the cat, the higher the arthritis burden. Overweight cats were particularly affected in the carpal, elbow, stifle, and hip joints. IGF-1 in the blood was significantly associated with the degree of arthritis. Leptin was strongly correlated with fat volume but showed no direct connection to arthritis burden. Adiponectin was higher in smaller cats but had no relation to fat mass or arthritis. Interestingly, it was found that indoor cats tended to have more body fat than outdoor cats.
Do Large Cat Breeds Also Have an Increased Risk for Arthritis?
This study stands out methodologically by using whole-body CT, allowing for an exact and comprehensive assessment of the entire skeleton–a clear advantage over previous X-ray studies. However, it should be noted that CT only detects bony changes (such as osteophytes)–early cartilage damage remains hidden. Additionally, the sample was deliberately skewed towards overweight cats to enable risk comparisons.
Furthermore, the researchers note towards the end of their study that a breed analysis was only possible to a limited extent, as many different cat breeds were included. Whether larger cat breeds like the Maine Coon or the Norwegian Forest Cat have a higher likelihood of joint wear due to their size could not yet be explored in this study.
However, the study provides the clearest evidence to date that obesity in cats is a clear risk factor for arthritis–not only in general but especially for specific joints. The positive correlation with IGF-1 suggests that this growth factor may play a role in the systemic response to joint changes. Leptin, although strongly correlated with fat, was surprisingly not directly associated with arthritis–which could indicate local, joint-proximal mechanisms. Overall, the study shows that CT-based diagnostics and hormonal markers can be valuable tools in the research and possibly also in the early detection of arthritis. 1