Arthritis in Cats vs Dogs: Why Cats Are Underdiagnosed & How Treatment Differs
Osteoarthritis (OA) is a common, progressive joint disease that causes pain, stiffness and reduced mobility in companion animals. Radiographic surveys and epidemiologic studies indicate that OA is extremely common in older cats and dogs: approximately 90% of cats aged 12 years and older and roughly 80% of dogs aged 8 years and older show radiographic evidence of degenerative joint disease.[1–3]
But prevalence alone doesn't tell the whole story. Cats are underdiagnosed and undertreated for OA far more often than dogs. This article compares the two species across prevalence, clinical presentation, diagnosis, and treatment, with detailed, practical recommendations for owners. It also reviews new species-specific biologic treatments — Solensia (frunevetmab) for cats and bedinvetmab (marketed as Librela in some regions) for dogs — and provides actionable environmental and monitoring advice.
Table of contents
- How common is OA: the numbers
- Why cats are underdiagnosed
- How pain and signs differ: cat vs dog
- Diagnosis: what vets use and what owners can track
- Treatment overview and species differences
- Solensia vs Librela (bedinvetmab): how they work, evidence, and practical points
- Environmental and lifestyle modifications (high-impact, low-cost)
- Monitoring, follow-up, and when to seek specialist care
- Practical timeline and checklist for owners
- References
How common is OA: the numbers
Comparing prevalence requires distinguishing radiographic prevalence (changes seen on X‑rays) from clinical diagnosis (symptoms recognized and recorded by a veterinarian). Radiographic prevalence studies consistently show high rates of OA in older animals:
| Species | Age group | Radiographic OA prevalence (approx.) | Source overview | |---|---:|---:|---| | Cat | ≥12 years | ~90% | Multi-center radiographic surveys & review articles reporting high prevalence of degenerative joint disease in geriatric cats [1,2]. | | Dog | ≥8 years | ~80% | Radiographic and clinical prevalence studies show OA signs increase markedly with age; many medium-to-large breeds show high prevalence by middle-old age [2,3]. |
Notes: “~” denotes approximate summary of multiple studies. Radiographic prevalence is higher than clinically recognized disease because many animals show structural change without obvious owner-reported signs.
References to prevalence data are summarized at the end of this article (Refs 1–3). Key points:
- A very large proportion of older cats have structural joint disease on imaging.[1]
- Dogs show a similar pattern of age-related increase, though clinical presentation often differs (more overt lameness in dogs).[2]
Why cats are underdiagnosed
There are several, interacting reasons cats with OA are frequently missed:
All together, these factors mean a typical clinic will identify far fewer cats with OA than radiographs suggest exist.
How pain and signs differ: cat vs dog
Owners and clinicians must recognize that the same disease manifests differently between species. Below is a direct comparison.
| Domain | Typical dog signs | Typical cat signs | Practical owner tips | |---|---|---|---| | Gait | Lameness, limb favoring, obvious limp | Subtle gait changes, slower turns, reluctance to jump | Video pets walking/jumping to show vet; note when/how behavior changes occurred | | Activity | Reduced exercise tolerance, stiffness after rest | Reduced play, fewer bursts of activity, sleeps more | Keep daily logs or use activity monitors/fit‑collars | | Jumping | Avoids stairs, trouble rising | Stops jumping onto counters, bed, windowsill | Provide ramps/steps; note decreased jump height/frequency | | Grooming | May be less affected | Poor grooming, matted abdomen, unkempt hair | Inspect coat regularly; consult vet if grooming drops | | Litter box | Noisy entry/exit; difficulty squatting | Litter box avoidance, urinating outside box (may be mobility, not behavior) | Use low-entry litter boxes; track box use patterns | | Pain vocalization | May whine or yelp | Rare vocalization — may become more withdrawn or aggressive | Note changes in temperament; record episodes of discomfort | | Appetite | May decrease with severe pain | Often maintains appetite until late; may eat less frequently | Track daily food intake and meal patterns |
Key takeaway: In dogs, lameness and overt stiffness drive owner concern. In cats, owners report changes in behavior and routine — these are equally important pain indicators.
Diagnosis: what vets use and what owners can track
Veterinarians combine history, physical exam, orthopedic palpation, gait analysis, and imaging. Diagnostics and tools differ slightly between species because of typical presentations.
Comparison of diagnostic methods
| Modality | Dogs | Cats | How owners can help | |---|---|---|---| | History & owner questionnaire (CBPI, LOAD) | CBPI, LOAD, Hudson scales commonly used | Feline Musculoskeletal Pain Index (FMPI) and other owner questionnaires | Keep a log, fill out validated forms; bring video to appointments | | Physical exam | Clear lameness, palpable pain, reduced ROM | Subtle pain on palpation, reduced activity, joint thickening may be missed | Allow vet to examine the cat in a quiet environment; stay with cat to reduce stress | | Radiographs (X‑ray) | Useful to confirm OA, assess joints | Useful but radiographic change may not correlate perfectly with pain | Expect X‑rays if treatment decisions need to be made | | Advanced imaging (CT/MRI) | Used for complex cases | Used less frequently due to anesthesia risk concerns | Consider referral if primary treatment fails or if neurologic signs appear | | Activity monitors | Widely used in trials for objective activity data | Increasingly used in feline trials and practice | Use vet‑recommended activity collars or apps to get baseline/monitoring data |
Important: Radiographs show structural changes but do not measure pain. Clinical assessment and owner‑reported function are essential for treatment decisions.
Treatment overview and species differences
OA management is multimodal: pain control, weight management, targeted exercise/physiotherapy, and environment modification. However, practical choices differ between dogs and cats because of drug approvals, safety, and behavioral differences.
Comparison of common treatment options
| Treatment | Dogs | Cats | Practical notes for owners | |---|---|---|---| | Weight loss | Cornerstone of therapy; even 5–10% loss helps | Equally important; weight reduction can markedly reduce load on joints | Calorie‑controlled diets + vet guidance; monitor monthly until goal reached | | NSAIDs | Widely used and effective (carprofen, meloxicam, grapiprant) | Historically limited; some NSAIDs used carefully; fewer labeled options | Never give OTC human NSAIDs; follow vet dosing and renal monitoring for cats | | Opioids | Short-term use for severe pain or post-op | Rarely used long-term in cats; can be used short-term | Discuss side effects and plan with your vet | | Gabapentin | Adjunctive for neuropathic pain; evidence mixed | Commonly used for chronic pain and anxiety in cats | Dose adjustments and tapering per vet; sedative effects noted | | Amantadine | NMDA antagonist, adjunctive use | Used off-label in some cats/dogs | Often part of multimodal protocols ─ discuss interactions | | Physiotherapy / Rehab | Common, effective (strengthening, range-of-motion, underwater treadmill) | Increasingly used; must adapt for cat temperament | Start with short, stress-free sessions; home exercises are helpful | | Joint nutraceuticals | Chondroitin, glucosamine, omega-3 FAs; mixed evidence | Widely used; high‑dose EPA/DHA has supportive data | Use vet-recommended formulations; monitor response over months | | Monoclonal antibodies (anti‑NGF) | Bedinvetmab (Librela in many regions) — monthly SC injections | Frunevetmab (Solensia) — monthly SC injection approved for cats | Typically given by vet every 4 weeks; shown to improve owner-assessed pain and activity in RCTs |
Practical considerations:
- Dogs tend to respond well to NSAIDs and multimodal rehab. Long-term NSAID use is common with monitoring.
- Cats require careful drug selection and monitoring because of hepatic and renal sensitivity; newer options (e.g., Solensia) expand choices.
Solensia vs Librela (bedinvetmab): what they are and evidence summary
Recent years have seen the development of species-specific monoclonal antibodies that target nerve growth factor (NGF), a key mediator of chronic pain signaling in OA. These therapies are administered by subcutaneous injection, generally once every 4 weeks, and are designed to reduce OA pain with potentially fewer systemic side effects than conventional analgesics.
High-level comparison
| Feature | Solensia (frunevetmab) — cats | Bedinvetmab (marketed as Librela in some regions) — dogs | |---|---|---| | Target | NGF (anti-NGF monoclonal antibody) | NGF (anti-NGF monoclonal antibody) | | Species | Cats (feline‑specific mAb) | Dogs (canine‑specific mAb) | | Administration | Subcutaneous injection, ~monthly | Subcutaneous injection, ~monthly | | Evidence | Randomized controlled trials show owner‑assessed improvement in mobility and pain; improved activity in some studies; generally well tolerated in trials [7,8] | Randomized controlled trials show reduced owner-reported pain and improved activity; good tolerability in trials [9,10] | | Practical vet considerations | New option that can be used where NSAIDs are limited or insufficient; monitor response and discuss combination therapy | Often used as part of multimodal protocols; may reduce reliance on NSAIDs in some patients |
What the trials show (summary):
- Cats: Frunevetmab (Solensia) randomized controlled trials demonstrated statistically significant improvements vs placebo on owner-completed pain/function assessments (e.g., FMPI) and in some objective activity measures. Adverse events were usually mild and included transient injection-site reactions and vomiting in a small percentage; long-term safety data are accumulating.[7,8]
- Dogs: Bedinvetmab/Librela trials showed statistically and clinically meaningful improvements in owner-assessed pain scores (CBPI and other measures) and activity monitoring. Tolerability was good, with some injection-site and GI adverse events reported in small numbers.[9,10]
- These agents are species-specific monoclonal antibodies — they are not interchangeable between cats and dogs.
- They are intended for monthly administration by a veterinarian (some practices allow owner administration after training depending on regional regulations).
- Response rates: trials report a proportion of treated animals achieving clinically meaningful benefit (varies by study); your vet will set realistic expectations and timeframes (typically 1–2 months to assess benefit).
- Cost: Monthly injections represent an ongoing cost; ask your clinic for pricing and expected duration of therapy before starting.
- Combination therapy: These biologics are often used alongside weight loss, environmental modification, and sometimes other analgesics (after veterinary assessment for safety).
Environmental and lifestyle modifications (high-impact, low-cost)
Because cats often show functional change instead of classic pain behaviors, environmental changes can produce rapid quality-of-life gains. Below are evidence-based, practical modifications ranked by likely impact.
High-impact (start immediately)
- Low‑entry litter boxes and multiple boxes on every level: reduce need to climb and decrease accidents. For arthritic cats, low entrances (≤4 cm) and large surface area help.[11]
- Ramps or step platforms to favorite perches/bed: allow cats to maintain vertical access without jumping. Soft steps or cat stairs near beds/windows work well.
- Elevated food/water at chest height for the cat: reduces strain when eating and drinking.
- Non-slip surfaces: rugs or shelf liners on slippery floors and steps to prevent missteps.
- Strategic placement of resources: food, water, litter boxes and resting spots should be close together and on the ground floor if mobility is limited.
- Orthopedic bedding and heated beds: warmth and pressure‑relieving surfaces can reduce joint stiffness.
- Interactive feeding puzzles that encourage slow, low‑effort activity: maintain muscle tone without high-impact exertion.
- Short, regular play sessions adapted to capability: maintain muscle and joint range.
- Weight management plan with prescription diet if overweight: 5–10% weight loss reduces joint load.
- Home physiotherapy exercises and controlled leash walks for dogs; for cats, encourage low-impact play and assisted stretching as advised by a vet or rehab specialist.
- Consider home ramps or furniture rearrangement for multi-cat homes to reduce competition for vertical spaces, which can stress arthritic cats.
- Install at least one low-entry litter box on each level used by the cat.
- Add a ramp or steps to the bed and to high windowsills if possible.
- Place food and water at a level that doesn’t require climbing.
- Add a warm, orthopedic bed in the cat’s favorite location.
- Record a 1–2 minute video of your pet walking and jumping for baseline assessment.
Monitoring, follow-up, and when to seek specialist care
Monitoring should be structured and objective where possible. Recommended approach:
- Baseline: Complete an owner assessment form (FMPI for cats, CBPI for dogs), obtain weight, and record video of mobility.
- Short-term (2–4 weeks): Re-assess appetite, litter box use (cats), and mobility. Expect some treatments to take 4–8 weeks for full effect.
- Medium-term (8–12 weeks): Re-evaluate using the same questionnaire and activity monitor data to determine response.
- Long-term: Regular checkups every 3–6 months depending on disease severity.
- Progressive neurologic signs (weakness, incoordination) or severe acute lameness.
- Poor response to appropriately implemented multimodal therapy.
- Need for advanced imaging or surgical consideration (e.g., joint replacement in dogs).
Practical timeline and owner action plan
Final practical tips for owners
- Do not give human pain medicines to pets. Many human NSAIDs are toxic to cats and can cause severe adverse effects in dogs if dosed incorrectly.
- Video is worth 1,000 words — bring short clips to appointments showing normal and abnormal behaviors.
- Consistency matters: small, cumulative changes (5–10% weight loss, ramps, monthly therapy) add up to meaningful improvements in mobility and [quality of life](https://seniorpet.org/knowledge/siamese-cat-quality-of-life "Quality of Life Assessment").
- Discuss realistic goals with your veterinarian — the aim is improved function and comfort, not necessarily elimination of radiographic disease.
References
(For full citations and links to primary literature, please consult your veterinarian or trusted veterinary resources such as the Journal of Veterinary Internal Medicine, Journal of Feline Medicine and Surgery, Veterinary Record, FDA and EMA product pages, and evidence‑based veterinary blogs and guidelines.)
Closing note
If you suspect your cat or dog has [arthritis](https://seniorpet.org/knowledge/golden-retriever-arthritis-pain-management "Arthritis Management in Senior Pets"), start with observation and documentation (video + owner questionnaires), contact your veterinarian for a diagnostic plan, and prioritize weight loss and environmental improvements immediately. New species‑specific treatments like Solensia (cats) and bedinvetmab/Librela (dogs) expand safe options for many pets, but the foundation of care remains a multimodal plan tailored to your pet's needs and monitored over time.
If you want, I can provide:
- A printable owner checklist for detecting cat arthritis (FMPI‑style)
- A template intake form for the veterinary visit (history + videos + questions to ask)
- A side-by-side cost and benefit worksheet to discuss with your clinic about monthly mAb therapy (Solensia/Librela)