Canine Osteoarthritis

What you might notice

• Slow or reluctant to get up from lying down, worst first thing in the morning or after a nap
• Stiff or limping for the first few minutes of a walk, then loosening up as they warm up
• Not wanting to do stairs, jump into the car, or get onto the sofa or bed any more
• Shorter walks: lagging behind, sitting down, or turning for home earlier than they used to
• Muscle wasting over the hips, shoulders or thighs, so the back end looks narrower
• Grumpiness, flinching, or moving away when touched over the hips, shoulders or elbows
• Sleeping more, playing less, greeting you from the bed instead of the door
• Slipping on smooth floors, or a wobbly, swaying back end
• Not a sign of arthritis but a warning sign about treatment: vomiting, diarrhoea, black or bloody stool, a drop in appetite, being flat and inactive, or yellowing of the gums or the whites of the eyes in a dog taking an anti-inflammatory - these are the specific adverse-effect signs FDA tells owners to watch for, and they mean stop and call, not wait and see

Standard of care

1. Get the dog lean, and treat weight as a therapeutic intervention rather than advice

   Approved / guideline-backed

   Calculate a target weight, prescribe a measured therapeutic weight-loss ration from a protein-adequate, complete-and-balanced therapeutic weight-management diet, weigh at every recheck, and record BCS and MCS numerically. This is the intervention with the best benefit-to-harm ratio in the whole protocol and it has objective gait-analysis support. Execute it safely: aim for gradual, controlled loss rather than crash restriction, re-weigh and re-calculate at every visit rather than setting a ration once, and do not achieve loss by simply cutting the volume of a maintenance food - restricting a maintenance diet far enough to produce loss also restricts protein and micronutrients, costing lean muscle in exactly the dog whose joints depend on it. Rule out and treat hypothyroidism and hyperadrenocorticism before deciding the weight is a feeding problem. The 2021 AAHA Nutrition and Weight Management Guidelines also address the communication problem directly, because owners often hear weight advice as a judgment of their own care.

   Named products: No drug is required, and none is recommended here. Therapeutic weight-management diets do the work. Historically one canine weight-reduction drug was FDA-approved - dirlotapide (Slentrol), approved for the management of obesity in dogs in 2007 - and it is no longer marketed; a second, mitratapide, was licensed outside the US and is also no longer marketed. So the honest statement is 'approved once, withdrawn from the market', not 'never existed'. No NADA number is printed here because it was not verified in this research pass. No GLP-1 agonist is approved for, or appropriate for, dogs - do not imply one is available.

   Open prospective clinical trial, 14 obese client-owned dogs with clinical and radiographic OA on a restricted-calorie diet over 16 weeks: significant decrease in lameness from 6.10% body-weight loss onward on numeric rating and visual analogue scales, supported by kinetic gait analysis from 8.85% body-weight loss onward. Species: dog, naturally occurring disease. Limitation: open-label, no control arm, n=14. Reinforced by a randomised (non-blinded) trial of 29 overweight dogs with OA in which caloric restriction plus intensive physiotherapy produced greater weight loss and the best improvement in mobility and ground-reaction-force symmetry at 6 months.

   Marshall WG, Hazewinkel HAW, Mullen D, De Meyer G, Baert K, Carmichael S. The effect of weight loss on lameness in obese dogs with osteoarthritis. Vet Res Commun. 2010;34(3):241-53. PMID 20237844; DOI 10.1007/s11259-010-9348-7. Mlacnik E et al. J Am Vet Med Assoc. 2006;229(11):1756-60. PMID 17144822; DOI 10.2460/javma.229.11.1756. Cline MG et al. 2021 AAHA Nutrition and Weight Management Guidelines for Dogs and Cats. J Am Anim Hosp Assoc. 2021;57(4):153-178. PMID 34228790; DOI 10.5326/JAAHA-MS-7232

2. Start an approved anti-inflammatory analgesic: an FDA-approved canine NSAID, or grapiprant

   Approved / guideline-backed

   NSAIDs were used in 88.31% of cases in the VetCompass elbow-disease cohort and remain the pharmacological backbone. Grapiprant is an EP4 prostaglandin-receptor antagonist and is mechanistically distinct from COX inhibitors. Baseline bloodwork, the lowest effective dose, and scheduled recheck plus repeat bloodwork are part of the standard, not optional extras - and so is naming in advance what would stop the drug. STOPPING AND WITHHOLDING RULES, stated so the owner can act on them: stop the drug and contact the practice for vomiting, diarrhoea, melaena or frank blood in the stool, anorexia, lethargy, or icterus of the gums or sclera - the exact owner-visible signs FDA lists. Withhold and reassess rather than continue if the dog becomes dehydrated, stops drinking, develops acute kidney or liver disease, is going to anaesthesia with a risk of hypotension, or starts a concurrent corticosteroid. ABSOLUTE COMBINATION RULES: never stack two NSAIDs, never combine an NSAID with a systemic corticosteroid, and never combine grapiprant with any other NSAID or corticosteroid - the Galliprant label says so in those words. Observe a washout when switching from one NSAID to another or from a corticosteroid to an NSAID; the carprofen, deracoxib and firocoxib labels all carry that instruction verbatim. CAUTION OR AVOID in dogs with chronic kidney disease, hepatic disease, existing or previous gastrointestinal ulceration or melaena, hypovolaemia or dehydration, bleeding disorders, or concurrent ACE inhibitor plus diuretic therapy for heart disease - the carprofen label names dehydration, concomitant diuretic therapy, and renal, cardiovascular or hepatic dysfunction as the greatest renal-toxicity risk factors, and does not recommend use in dogs with bleeding disorders such as von Willebrand's disease.

   Named products: FDA-APPROVED FOR THE CONTROL OF OSTEOARTHRITIS PAIN AND INFLAMMATION IN DOGS, with their own label boundaries: carprofen (Rimadyl, NADA 141-053) - safe use not established in dogs under 6 weeks of age, in pregnant dogs, in dogs used for breeding, or in lactating bitches; not recommended in dogs with bleeding disorders; 'For use in dogs only. Do not use in cats.' Deracoxib (Deramaxx, NADA 141-203) - osteoarthritis dose 1 to 2 mg/kg/day as a single daily dose; the separate post-operative orthopaedic-surgery indication is 3 to 4 mg/kg/day NOT TO EXCEED 7 DAYS and the dental indication is 1 to 2 mg/kg/day for 3 days, so the post-surgical regimens are hard-capped and are not the chronic OA regimen; dogs requiring less than 12.5 mg cannot be accurately dosed; 'Do not use in cats.' Firocoxib (Previcox, NADA 141-230) - osteoarthritis indication plus a separate post-operative soft-tissue and orthopaedic indication dosed for 3 days; doses above 2.27 mg/lb in puppies under 7 months of age have been associated with serious adverse reactions including death; dogs under 12.5 lb cannot be accurately dosed; for oral use in dogs only. Meloxicam oral suspension for dogs - indicated for the control of pain and inflammation associated with osteoarthritis in dogs; safe use in dogs younger than 6 months has not been evaluated; the label carries a BOXED WARNING that 'Repeated use of meloxicam in cats has been associated with acute renal failure and death. Do not administer additional injectable or oral meloxicam to cats.' Grapiprant (Galliprant, NADA 141-455, Elanco) - contraindicated in dogs hypersensitive to grapiprant; safe use has NOT been evaluated in dogs younger than 9 months of age or under 8 lb (3.6 kg), nor in dogs used for breeding or in pregnant or lactating dogs; use in dogs with cardiac disease has not been studied; 'Do not administer GALLIPRANT in conjunction with any other oral or injectable NSAID or corticosteroid.' NOT FDA-APPROVED FOR CANINE OSTEOARTHRITIS - ROBENACOXIB. In the US, the Onsior tablet is labelled 'For Oral Use In Cats Only' and is indicated only for post-operative pain and inflammation in cats at least 5.5 lb (2.5 kg) and at least 4 months of age, for up to a maximum of 3 days (NADA 141-320). The Onsior injection's canine indication is the control of post-operative pain and inflammation associated with soft tissue surgery in dogs at least 4 months of age, for up to a maximum of 3 days (NADA 141-443). There is no US robenacoxib osteoarthritis indication in dogs, and a 3-day-maximum post-surgical product must not be used as chronic OA therapy. Oral robenacoxib IS authorised for canine osteoarthritis in the European Union - that is an EMA/European Commission authorisation and must never be described as an FDA approval. NONE OF THE DRUGS IN THIS STEP MAY BE EXTRAPOLATED TO CATS.

   Double-blind, randomised, placebo-controlled trial in 70 dogs with OA: carprofen produced significant improvement in CBPI pain severity (median 4.25 to 2.25) and pain interference (4.33 to 2.67) over 14 days while placebo did not, with a significantly greater improvement than placebo. A companion analysis in 68 dogs showed carprofen also significantly increased peak vertical force and vertical impulse versus placebo. On objective kinetics the accurate comparison is this: carprofen has placebo-controlled force-plate evidence (Brown 2013, n=68); bedinvetmab and grapiprant have only a single small active-controlled force-plate comparison against each other (Enomoto 2026, n=32) and no placebo-controlled force-plate data. Species: dog, naturally occurring disease.

   Brown DC, Boston RC, Coyne JC, Farrar JT. Ability of the canine brief pain inventory to detect response to treatment in dogs with osteoarthritis. J Am Vet Med Assoc. 2008;233(8):1278-83. PMID 19180716; DOI 10.2460/javma.233.8.1278. Force-plate arm: Brown DC, Boston RC, Farrar JT. J Vet Intern Med. 2013;27(1):22-30. PMID 23311715; DOI 10.1111/jvim.12004. Practice pattern: O'Neill DG et al. Canine Med Genet. 2020;7:1. PMID 32835227; DOI 10.1186/s40575-020-0080-5. Label text: DailyMed FDA animal-drug labels for RIMADYL (NADA 141-053), DERAMAXX (NADA 141-203), PREVICOX (NADA 141-230), meloxicam oral suspension for dogs, GALLIPRANT (NADA 141-455), ONSIOR tablets (NADA 141-320) and ONSIOR injection (NADA 141-443).

3. Prescribe controlled, regular exercise and structured physical rehabilitation - not rest

   Controlled trial in this species

   Replace long weekend walks with shorter, consistent daily lead exercise; add non-slip flooring, ramps in place of jumps, raised food bowls, and traction on stairs. Refer for physical rehabilitation where available. This is the modality that makes the weight-loss step achievable in a dog that hurts.

   Named products: Not applicable.

   Randomised (non-blinded) prospective clinical trial, 29 overweight or obese dogs with clinical and radiographic OA: caloric restriction plus an intensive physiotherapy programme including transcutaneous electrical nerve stimulation achieved greater weight loss and the best improvement in mobility and ground-reaction-force symmetry at 6 months compared with caloric restriction plus home-based therapy. Species: dog, naturally occurring disease. Limitation: not blinded, both arms received an active intervention, so the physiotherapy increment is confounded with the additional weight loss it produced. The 2022 AAHA guidelines place non-pharmacological modalities inside the tiered multimodal plan.

   Mlacnik E, Bockstahler BA, Muller M, Tetrick MA, Nap RC, Zentek J. Effects of caloric restriction and a moderate or intense physiotherapy program for treatment of lameness in overweight dogs with osteoarthritis. J Am Vet Med Assoc. 2006;229(11):1756-60. PMID 17144822; DOI 10.2460/javma.229.11.1756

4. Consider bedinvetmab (anti-NGF monoclonal antibody) as an FDA-approved option - with informed consent, label boundaries and baseline imaging

   Approved / guideline-backed

   Bedinvetmab is a caninised anti-nerve-growth-factor monoclonal antibody, FDA-approved 5 May 2023 (NADA 141-562) to control pain associated with osteoarthritis in dogs. Its EU marketing authorisation was granted by the European Commission in November 2020 (CVMP positive opinion 9 September 2020; EMEA/V/C/005180); the day-level EC decision date could not be verified from a primary source and is therefore not stated. It is a genuinely approved biologic and the best-evidenced injectable in this category. The effect size is real but modest, the US pivotal study's own primary endpoint did not reach significance in FDA's analysis, and the post-marketing musculoskeletal safety signal is now serious enough that the honest presentation includes it. Discuss it, document the discussion, image the joint first, schedule follow-up imaging, and agree IN WRITING AND WITH THE OWNER what finding would stop treatment - then tell the owner in plain language which changes to report before the next dose (any new limp, a worsening limp, a limp that moves to another leg or a joint that was not treated, joint swelling or deformity, or sudden inability to bear weight). LABEL BOUNDARIES, which an informed-consent conversation cannot omit: LIBRELA should not be administered to dogs with known hypersensitivity to bedinvetmab; it 'should not be used in breeding dogs or in pregnant or lactating dogs' because IgG-class antibodies can cross the placenta and be excreted in milk; safety and effectiveness have not been evaluated in dogs less than 12 months of age; monoclonal antibodies may be associated with immediate and delayed hypersensitivity reactions. HUMAN HANDLING: hypersensitivity reactions including anaphylaxis could occur with accidental self-injection, and pregnant women, women trying to conceive and breastfeeding women should take extreme care to avoid accidental self-injection, because NGF is important in normal fetal nervous-system development and nonhuman-primate studies of human anti-NGF antibodies showed reproductive and developmental toxicity. Seek medical advice immediately after accidental self-injection and show the leaflet to the physician.

   Named products: Bedinvetmab (Librela, Zoetis, NADA 141-562, FDA-approved 5 May 2023; EU authorisation granted by the European Commission in November 2020, EMEA/V/C/005180). The feline anti-NGF product is a DIFFERENT molecule with a separate approval - frunevetmab (Solensia, NADA 141-546, approved 13 January 2022, cats only). Never cross-label the two, and never redose one species with the other's product.

   Two peer-reviewed, sponsor-authored (Zoetis) pivotal RCTs, plus FDA's own review of the same two studies. EU trial: n=287 (141 bedinvetmab / 146 placebo), day-28 CBPI treatment success 43.5% vs 16.9%, p=0.0017 (Corral et al. 2021, PMID 34565678; DOI 10.1016/j.vaa.2021.08.001). US trial: n=272 (135 bedinvetmab / 137 placebo), day-28 CBPI success 47.4% vs 36.6%, p=0.0410, number needed to treat 9.3 and standardised effect size 0.3 at day 28 (Michels et al. 2023, PMID 37541934; DOI 10.1016/j.vaa.2023.06.003). THE REGULATORY READING OF THE SAME DATA MUST BE GIVEN ALONGSIDE THE JOURNAL READING. FDA's Freedom of Information Summary for NADA 141-562 states verbatim: 'There was a significant difference in treatment success rates between the treatment and control groups on Day 28 in the EU study but not in the US study.' FDA's least-squares-mean Day 28 figures are 48.0% Librela vs 36.1% control in the US study, P = 0.0719 - the US pivotal study's pre-specified primary effectiveness endpoint FAILED - and 45.2% vs 17.0%, P = 0.0018 in the EU study. FDA states that 'a weight of evidence approach was employed' and that approval rests on the consistency of the Librela results across both studies and the Day 42 through Day 84 differences, concluding effectiveness 'when at least two doses are given 28 days apart'. Both definitions of treatment success in use should be named: the pivotal trials and FDA used a reduction of at least 1 in pain severity AND at least 2 in pain interference, while some other canine trials used at least 1 in both. HEAD TO HEAD ON FORCE PLATE, WITH ITS FULL DESIGN DISCLOSED: a randomised, double-blind, ACTIVE-controlled non-inferiority trial with NO PLACEBO ARM in 32 dogs (16 per arm), restricted to dogs over 20 kg and at least 1 year old with osteoarthritis exclusively at hips and/or stifles, with an a priori non-inferiority margin of 21.25% at day 42. Force-plate treatment success at day 42 was 68.8% for bedinvetmab and 56.3% for grapiprant, difference 12.5% (90% CI -37.5 to 18.8); because the upper bound fell below the margin, bedinvetmab was concluded NON-INFERIOR, not superior, and the authors concluded both are appropriate first-line treatments (Enomoto et al. 2026, PMID 41667566; DOI 10.1038/s41598-026-37626-4). A 16-per-arm trial with a 21.25% margin, in one weight class and two joint groups, cannot be generalised beyond that population and cannot carry a broad claim of objective superiority. SAFETY: FDA issued a Dear Veterinarian Letter on adverse events including neurological signs, and the US label's post-approval adverse reactions include ataxia, seizures, paresis, proprioceptive deficits, paralysis, anorexia, lethargy and recumbency. A EudraVigilance disproportionality analysis (2004-2024) of Librela against six comparator OA drugs reported ligament/tendon injury, polyarthritis, fracture, musculoskeletal neoplasia and septic arthritis approximately 9 times more frequently than the combined total for the comparators, and an 18-member expert panel reviewing 19 adjudicated cases unanimously concluded a strong suspicion of a causal association with accelerated joint destruction (Farrell et al. 2025, PMID 40417367; DOI 10.3389/fvets.2025.1581490). A separate JAVMA analysis notes that NGF inhibition is associated with rapidly progressive osteoarthritis in humans, rodents and rabbits - the adverse event that prevented regulatory approval of human anti-NGF antibodies - and raises concern about both index and non-index joints (von Pfeil et al. 2026, PMID 42361372; DOI 10.2460/javma.26.03.0170). THE FIGURE MOST OFTEN USED TO SOFTEN THAT SIGNAL MUST BE ATTRIBUTED AND CONFLICTED: the 18.1 million-dose pharmacovigilance dataset is Monteiro BP, Simon A, Knesl O, Mandello K, Nederveld S, Olby NJ, Innes JF, Lascelles BDX. Front Vet Sci. 2025;12:1558222 (PMID 40343372) - an analysis of the ZOETIS Global Pharmacovigilance database, most of whose authors are employees of Zoetis, the marketing authorisation holder. It reports 18,102,535 doses sold from 1 February 2021 to 30 June 2024 with 17,162 canine adverse events, i.e. 9.48 events per 10,000 treated animals, lack of efficacy the highest single term at 1.70 per 10,000, with polydipsia, ataxia, polyuria/pollakiuria, anorexia, lethargy, DEATH and emesis also in the rare band; median age of reported dogs 12 years (IQR 10-13) and median weight 26 kg. Spontaneous reporting rates systematically under-capture events and are NOT incidence, and this is the manufacturer's own database - it is not the independent counterweight to Farrell et al. Species: dog throughout.

   FDA Freedom of Information Summary, Librela (bedinvetmab injection), NADA 141-562, approved 5 May 2023: https://animaldrugsatfda.fda.gov/adafda/app/search/public/document/downloadFoi/13959 . Efficacy: Corral MJ et al. Vet Anaesth Analg. 2021;48(6):943-955. PMID 34565678; DOI 10.1016/j.vaa.2021.08.001. Michels GM et al. Vet Anaesth Analg. 2023;50(5):446-458. PMID 37541934; DOI 10.1016/j.vaa.2023.06.003. Non-inferiority: Enomoto M et al. Sci Rep. 2026. PMID 41667566; DOI 10.1038/s41598-026-37626-4. Independent safety analyses: Farrell M et al. Front Vet Sci. 2025;12:1581490. PMID 40417367; DOI 10.3389/fvets.2025.1581490; von Pfeil DJF et al. J Am Vet Med Assoc. 2026. PMID 42361372; DOI 10.2460/javma.26.03.0170. Manufacturer-affiliated pharmacovigilance analysis: Monteiro BP et al. Front Vet Sci. 2025;12:1558222. PMID 40343372; DOI 10.3389/fvets.2025.1558222. Label: DailyMed LIBRELA (bedinvetmab injection), NADA 141-562.

5. Fix the correctable lesion surgically when one exists, instead of injecting around it

   Approved / guideline-backed

   Osteoarthritis secondary to a mechanically unstable or surgically addressable lesion is a different clinical problem. Cranial cruciate ligament rupture is the clearest case: the strongest causal evidence in canine orthopaedics favours surgery, not injectables. The same logic applies to fragmented medial coronoid process, osteochondritis dissecans lesions, and severe patellar luxation. Establish whether a surgical indication exists before any injectable is discussed.

   Named products: Not applicable - surgical referral.

   Target-trial-emulation analysis of 615 surgically and 200 non-surgically managed cases of canine CCL rupture in UK primary care: published risk differences of -25.7% (95% CI -36.7 to -15.9) for short-term lameness and -31.7% (95% CI -37.9 to -18.1) for long-term lameness, both favouring surgery. Species: dog, naturally occurring disease, real-world primary-care data with a causal-inference design. TWO CAVEATS THAT MUST TRAVEL WITH THESE NUMBERS: the published long-term point estimate lies outside its own published confidence interval, so it must not be quoted as a precise effect size - say 'substantially reduced long-term lameness', not 'by 32 percentage points'; and this is an emulation of observational data in which confounding by indication was adjusted for, not eliminated, since insured and heavier dogs were far more likely to receive surgery.

   Pegram C et al. Target Trial Emulation: Does surgical versus non-surgical management of cranial cruciate ligament rupture in dogs cause different outcomes? Prev Vet Med. 2024;226:106165. PMID 38503655; DOI 10.1016/j.prevetmed.2024.106165

6. Add omega-3 fatty acids, from an enriched therapeutic diet or a dosed supplement

   Controlled trial in this species

   This is the only nutraceutical category in the canine OA literature with evident analgesic efficacy on systematic review. Deliver it as a defined dose from a quality-controlled source, not as an unspecified joint supplement. Tell the owner not to add it, or any other supplement, without saying so - high-dose marine oils can affect platelet function and gastrointestinal tolerance alongside an NSAID, and the calories in an oil supplement count against the weight-loss plan that is doing most of the work.

   Named products: Omega-3 (EPA/DHA) enriched therapeutic diets and marine-oil supplements. No approved drug claim, no FDA-approved product, and no label-level dose.

   PROSPERO-registered systematic review and meta-analysis (CRD42021279368), 57 articles comprising 72 trials across nine categories of natural health product in dogs and cats with osteoarthritis: omega-3-enriched diets and omega-3 supplements showed evident clinical analgesic efficacy; cannabidiol showed efficacy to a lesser degree; collagen weak efficacy. Species: dogs and cats pooled, which is a real limitation of the review for a dog-only claim.

   Barbeau-Gregoire M, Otis C, Cournoyer A, Moreau M, Lussier B, Troncy E. A 2022 Systematic Review and Meta-Analysis of Enriched Therapeutic Diets and Nutraceuticals in Canine and Feline Osteoarthritis. Int J Mol Sci. 2022;23(18):10384. PMID 36142319; DOI 10.3390/ijms231810384

7. Escalate multimodally under the AAHA tiered framework rather than by adding unproven injections

   Approved / guideline-backed

   When an approved first-line analgesic is insufficient, work through the guideline's tiered decision tree - reassessing the diagnosis, adding or substituting modalities with the best efficacy evidence, and treating adjacent contributors such as comorbid pain sources and reduced sleep. Proactive and pre-emptive analgesia beats reactive dose-chasing. Every escalation is a prescribing decision made by the veterinarian, not an owner adjustment: the owner's instruction is to report and to call, never to alter a dose.

   Named products: Guideline framework; agent selection is patient-specific. Note that tramadol, despite being recorded in 19.64% of the VetCompass elbow-disease cohort, failed in a randomised blinded placebo-controlled crossover trial (see the negative-evidence step below). Chronic systemic glucocorticoids are not an osteoarthritis strategy in dogs, and must never be layered onto an NSAID.

   Expert consensus guideline, not an RCT. The 2022 AAHA Pain Management Guidelines provide assessment algorithms for acute and chronic pain, describe owner-facing pain-assessment instruments, and give a tiered decision tree prioritising the most efficacious modalities. Consensus is not trial evidence and should be labelled as such.

   Gruen ME, Lascelles BDX, Colleran E, Gottlieb A, Johnson J, Lotsikas P, Marcellin-Little D, Wright B. 2022 AAHA Pain Management Guidelines for Dogs and Cats. J Am Anim Hosp Assoc. 2022;58(2):55-76. PMID 35195712; DOI 10.5326/JAAHA-MS-7292

8. Cannabidiol: a weaker but real signal, on an unresolved regulatory position, with its own safety profile

   Early evidence

   The 2022 meta-analysis found cannabidiol efficacious to a lesser degree than omega-3 in canine and feline osteoarthritis. There is no FDA-approved cannabidiol product for dogs, product quality and labelling accuracy vary, and legality differs by jurisdiction. If it is used, it should be as an adjunct with an owner score measured before and after, never as a replacement for an approved analgesic, and never added without telling the veterinary team. SAFETY, WHICH THE LEGAL CAVEAT DOES NOT COVER: serum alkaline phosphatase rises on oral cannabidiol in a large minority of dogs - a randomised, placebo-controlled, blinded 6-month study of broad-spectrum CBD at 4 mg/kg once daily in 40 healthy dogs found transient ALP elevation in just over half of the CBD group, without concurrent elevation of other liver parameters and with bone alkaline phosphatase rising in parallel, so much of the signal was bone-derived rather than hepatic; the authors concluded the dose was well tolerated (Bradley et al. 2022, PMID 36213402). That is a reason to take baseline and follow-up liver enzymes and to interpret an isolated ALP rise with care, not a reason to claim the drug is hepatotoxic - and not a reason to claim it is harmless. Gastrointestinal effects including soft stool and diarrhoea are commonly reported. Cannabidiol is metabolised hepatically and can interact with concurrently administered NSAIDs and other hepatically cleared drugs, so it is a prescribing conversation, not a supplement the owner adds. And because these are unregulated products, actual potency may not match the label and THC contamination occurs - a product sold as CBD can cause cannabis intoxication in a dog. Formulation is not interchangeable either: an injectable liposomal synthetic CBD studied in 8 dogs is a different product from an oral oil and caused two days of fever and local swelling (PMID 41635790).

   Named products: No approved canine cannabidiol product exists in the US. Do not present any cannabidiol product as FDA-approved or as veterinary-labelled unless a specific approval can be produced. No dose is printed here as a recommendation.

   Same PROSPERO-registered systematic review and meta-analysis as the omega-3 step (57 articles, 72 trials, dogs and cats pooled). Cannabidiol: efficacy demonstrated, to a lesser degree. No approved product and no regulatory efficacy determination. Safety: Bradley S, Young S, Bakke AM, Holcombe L, Waller D, Hunt A, Pinfold K, Watson P, Logan DW. Long-term daily feeding of cannabidiol is well-tolerated by healthy dogs. Front Vet Sci. 2022;9:977457. PMID 36213402; DOI 10.3389/fvets.2022.977457 - randomised, placebo-controlled, blinded, 20 dogs on CBD and 20 on placebo, 6 months plus 4-week washout, healthy dogs not OA dogs, and the authors are employees of a pet-food research institute.

   Barbeau-Gregoire M et al. Int J Mol Sci. 2022;23(18):10384. PMID 36142319; DOI 10.3390/ijms231810384. Safety: Bradley S et al. Front Vet Sci. 2022;9:977457. PMID 36213402; DOI 10.3389/fvets.2022.977457. Injectable formulation: Shilo-Benjamini Y et al. Front Vet Sci. 2025;12:1746266. PMID 41635790; DOI 10.3389/fvets.2025.1746266

9. Stop recommending glucosamine-chondroitin, and do not use tramadol as a substitute for an effective analgesic

   No evidence located

   Two of the most commonly used things in canine OA have been tested and failed. Saying so is part of the standard of care, because every dollar and every week spent on them is a dollar and a week not spent on weight loss and an approved analgesic. This is a NEGATIVE recommendation, not a neutral option: it should not be softened into 'these may be used'. It is also not an instruction for an owner to act on alone - if your dog is currently on either one, raise it at the next visit rather than changing anything yourself.

   Named products: Glucosamine hydrochloride / chondroitin sulphate products: negative evidence. Tramadol hydrochloride: negative evidence at 5 mg/kg PO q8h as monotherapy in canine OA.

   Glucosamine-chondroitin: the 2022 systematic review and meta-analysis reports a very marked non-effect and its authors recommend these products should no longer be recommended for pain management in canine and feline osteoarthritis (PMID 36142319). Tramadol: randomised, blinded, placebo-controlled crossover trial, 40 dogs with elbow or stifle OA, 35 completing; tramadol at 5 mg/kg PO q8h for 10 days produced no significant change from baseline in vertical impulse, peak vertical force or CBPI, while carprofen in the same dogs improved all three - authors concluded tramadol provided no clinical benefit. Species: dog, naturally occurring disease, within-dog comparison.

   Budsberg SC, Torres BT, Kleine SA, Sandberg GS, Berjeski AK. Lack of effectiveness of tramadol hydrochloride for the treatment of pain and joint dysfunction in dogs with chronic osteoarthritis. J Am Vet Med Assoc. 2018;252(4):427-432. PMID 29393744; DOI 10.2460/javma.252.4.427. Barbeau-Gregoire M et al. Int J Mol Sci. 2022;23(18):10384. PMID 36142319; DOI 10.3390/ijms231810384

How it is diagnosed

• History plus a validated owner-completed clinical metrology instrument at the first visit (CBPI or LOAD), because the AAHA guidelines make owner-captured assessment central to chronic pain evaluation and because it establishes the baseline that later response is measured against (Gruen et al. 2022, PMID 35195712; DOI 10.5326/JAAHA-MS-7292)
• Gait observation at walk and trot on a non-slip surface, plus body condition score AND muscle condition score recorded numerically - the 2021 AAHA nutrition guidelines call for both at every examination (Cline MG et al. J Am Anim Hosp Assoc. 2021;57(4):153-178. PMID 34228790; DOI 10.5326/JAAHA-MS-7232)
• Systematic orthopaedic examination of every limb and joint: range of motion, pain on manipulation, effusion, crepitus, thickening and periarticular muscle mass, with the contralateral side as the within-patient comparison
• Orthogonal radiographs of the clinically implicated joints, with sedation for correct positioning; image the contralateral joint because elbow and hip disease is frequently bilateral even when lameness is unilateral
• Exclude the differentials that change the plan entirely: cranial cruciate ligament rupture (surgical), immune-mediated polyarthropathy and septic arthritis (arthrocentesis and synovial fluid cytology when there is effusion, pyrexia, multi-joint involvement or acute deterioration), primary or metastatic bone neoplasia - a focal, painful, expansile long-bone lesion in a large-breed dog is osteosarcoma until radiographs say otherwise, and it is the classically missed diagnosis in a dog already carrying an arthritis label - and neurological disease including intervertebral disc disease and lumbosacral stenosis, which mimics hip pain
• Baseline CBC, serum biochemistry and urinalysis before starting chronic NSAID therapy, and a documented plan for repeat monitoring. Record hydration status, concurrent ACE inhibitor or diuretic therapy, and any history of melena or gastrointestinal ulceration before the first dose, because those are the specific label-level risk factors that change whether an NSAID should be started at all
• In an overweight dog, screen for the endocrine disease that makes weight gain a symptom rather than a feeding failure - hypothyroidism and hyperadrenocorticism - before attributing the weight to intake alone, and treat it if present
• Where available, an objective baseline: force-plate or pressure-sensitive-walkway gait analysis. Owner scores and force-plate measures do not correlate with each other in dogs with osteoarthritis (Brown et al. 2013, PMID 23311715; DOI 10.1111/jvim.12004), so they answer different questions and neither substitutes for the other
• If an anti-NGF monoclonal antibody is being considered, obtain and archive baseline radiographs first - the published safety critique specifically calls for baseline and follow-up imaging and documented informed consent (von Pfeil et al. 2026, PMID 42361372; DOI 10.2460/javma.26.03.0170)
• Before any intra-articular injection of anything - cells, secretome, platelet-rich plasma, hyaluronic acid or corticosteroid - rule out infection in that joint. If there is effusion, pyrexia, disproportionate pain, multi-joint involvement or a recent injection into the same joint, perform arthrocentesis with cytology first. Never inject a joint that might be septic, and never inject a corticosteroid into a joint under suspicion of infection