Arthritis in Labradors: The Weight Connection Nobody Wants to Hear About

Arthritis is one of the most common ways a Labrador's later years go wrong, and the strongest lever against it is not a supplement — it is the amount of food in the bowl. In the lifetime study that followed 48 Labrador littermates from eight weeks of age until death, the dogs fed 25% less lived a median 1.8 years longer, with delayed onset of late-life disease and especially of osteoarthritis. That number is smaller than the "two years" you will see quoted, it is still bigger than anything else on this page, and it comes with conditions worth knowing.

Why do Labradors get arthritis so often?#

Three rails run under this breed's joint problems, and they compound.

The orthopedic genetics. Osteoarthritis is this breed's single strongest recorded predisposition. In UK primary-care records comparing 1,462 Labradors against 20,786 other dogs, osteoarthritis had the highest odds ratio of 35 disorders examined, at 2.83 (95% CI 2.21–3.62).^[1] Underneath it sit the two joints the breed inherits badly. Of 13,125 Labradors screened in Sweden between 2007 and 2016, 16.2% graded C to E for hips — the dysplastic range — and of 13,057 screened for elbows, 9.0% graded ED 1 or worse.^[2]

Elbows deserve particular mention, because they are underdiagnosed and because this breed carries an extraordinary risk. In a study of 455,069 dogs under UK primary care, elbow joint disease had a one-year prevalence of 0.56% overall — and the Labrador's multivariable odds ratio was 5.94 (95% CI 4.65–7.60).^[3] And the front legs are where the weight is: measured on a pressure walkway, standing Labradors carried 69% (±5%) of their body weight on the forelimbs, against 62% (±2%) in German Shepherds.^[4] Front-end stiffness in a middle-aged Lab is elbows until a radiograph says otherwise. If your Lab already has a hip diagnosis, our hip dysplasia guide covers that road in detail.

The appetite. This is the genuinely breed-specific part. Cambridge researchers sequenced obesity candidate genes in Labradors and found a 14-base-pair deletion in POMC, disrupting the coding sequence for β-MSH and β-endorphin, at an allele frequency of 12%. Each copy was associated with greater body weight, greater adiposity and greater food motivation, and among other breeds the deletion turned up only in the closely related flat-coated retriever.^[5] Your dog is not greedy; a meaningful minority of this breed is wired. The practical consequence is that a Lab will always vote for more food, and the vote does not mean hunger.

The third rail is us. Take a breed that always says yes to food, add treat-based training and those eyes. In VetCompass records of 2,074 Labradors under UK primary care, overweight or obese was the second most commonly recorded disorder in the breed at 8.8% (95% CI 7.6–10.1) — and note that is what a vet wrote down, not what a scale would find.^[6] We looked for a published league table putting Labradors at the top of a breed obesity ranking and did not find one we could quote, so we are not printing that claim.

Extra weight hurts joints twice. It adds mechanical load, and fat tissue itself is endocrine: in 26 overweight dogs put through a weight-loss programme, plasma TNF-alpha, haptoglobin and C-reactive protein all fell measurably, along with insulin resistance.^[7] The fat is not inert padding. It is a source of the inflammatory signalling that makes an arthritic joint hurt more.

For what arthritis actually is inside the joint, and every treatment tier from weight to prescription injections, see our arthritis master guide. For the whole-lifespan orthopedic profile of the breed — screening ages, elbow grades, neuter timing — see Labrador retriever joint problems. This page is the arthritis playbook.

What is the evidence that weight matters this much?#

The centerpiece is one of the most remarkable studies in veterinary medicine, and it deserves reporting properly rather than as a slogan.

Forty-eight Labradors from seven litters were paired at six weeks by sex and weight. From eight weeks of age until death, one dog in each pair was fed 25% less of the same food than its pair-mate. Same genetics, same environment, one variable.^[8] The restricted dogs lived a median 1.8 years longer, with delayed onset of late-life disease, especially osteoarthritis.^[9][10]

And the joint effect was not subtle. Median age at first radiographic evidence of hip osteoarthritis was 6 years in the control-fed dogs against 12 in the restricted ones — while across the whole cohort, prevalence climbed from 15% at two years to 67% by fourteen.^[11] Six years of hip comfort, from a scoop.

Now three caveats, because this study is misquoted constantly and every misquote runs in the flattering direction.

It is 1.8 years, not two. Small point, but we had "roughly two years" on this page and it is worth being exact about the one number everybody repeats.

It was lifetime restriction from puppyhood. The feeding difference began at eight weeks and ran until death.^[8] Slimming a heavy eight-year-old is a different intervention, and it has its own — smaller — number. Across 11,867 client-owned Labradors, overweight body condition in middle age carried a hazard ratio for death of 1.83 (99.79% CI 1.54–2.17) against normal condition.^[12] Both numbers are true; they measure different things. Our whole-breed profile works through the full set of caveats, including the body condition scores the two groups actually held.

It did nothing measurable for elbows. This matters more in this breed than anywhere, because the elbow is its biggest structural predisposition. In the elbow-specific analysis of the same 48 dogs there was no statistical difference in radiographic osteoarthritis frequency between the feeding groups at any time point, no difference in histopathologic prevalence or severity, and no difference in gross lesions — only severity at six years reached significance.^[10] Anyone telling you leanness protects a Labrador's elbows is going beyond the only lifetime study that looked.

None of that undoes the point. It reframes the guilt without inflating the promise: cutting your Lab's food back is not deprivation, and the hips are where you will see it.

Is my Lab overweight? The 60-second check#

Vets score body condition on a validated nine-point scale, and you can run the core of it at home with your hands and your eyes.^[13]

Two honest notes. Owners score their own dogs leaner than the vet does, and there is a number on it: of 304 dogs assessed in French veterinary practices, 27% of owners underestimated their dog's body condition against the clinician's score, and underestimation was more likely in the dogs that were genuinely overweight.^[13] If you are unsure, assume heavy. And a correctly lean Lab looks slightly skinny to the modern eye — expect a relative to say so at Thanksgiving.

Making it happen: weigh meals on a kitchen scale instead of eyeballing a scoop, count every treat as part of the day's ration, and shrink the training treats. For a big reduction, work from a vet-guided plan rather than crash-dieting.

If a Lab keeps gaining on sensible rations, thyroid testing is a fair thing to raise — with a caveat in both directions. In 905,553 UK dogs under primary care, the Labrador was among the predisposed breeds for a hypothyroidism diagnosis, at an odds ratio of 1.40 (95% CI 1.16–1.68), though the annual prevalence across all dogs was only 0.23%.^[14] So: a real but modest predisposition to an uncommon disease. The caveat running the other way is that hypothyroidism appears to be over-diagnosed — when three specialists reviewed 102 dogs already being treated for it in first-opinion practice, each judged that levothyroxine was not indicated in between 45% and 59% of them.^[15] Ask for the test if the picture fits. Do not go looking for a diagnosis that lets the bowl off the hook.

How should I exercise a stiff Lab?#

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The rule for arthritic joints is consistency over intensity. Muscle is what stabilizes a failing joint, and muscle is kept with regular, moderate, low-impact work — not with a two-hour weekend adventure that leaves the dog wrecked until Wednesday.

• Swimming, with a caveat about the evidence. Water carries the dog's weight, so the muscle work happens with far less load through the joint, and most Labs take to it without persuasion. That is a reasoning argument: searching Europe PMC on 14 August 2026 we found no controlled trial testing swimming or hydrotherapy as a treatment for canine osteoarthritis, only physiological-load work in healthy dogs. Use a gradual entry rather than repeated bank-leaping, which undoes the point, and dry the ears afterwards.
• Short and frequent beats long and rare. Two or three shorter walks spread across the day serve stiff joints better than one long haul.
• The fetch conversation. This is the hard one for Lab owners. A ball-launcher session is dozens of maximum-effort sprint-brake-twist cycles, and every skidding stop hammers exactly the elbows and knees that already hurt. Labs will not self-limit; in this breed, obsession outruns pain. You do not have to ban the ball — ration the throws, roll it along the ground instead of launching it, and stop while the dog still moves well. Scent games burn the same mental energy at walking pace.

Watch the day after, not just the day of: next-day stiffness means yesterday was too much. Soreness is easy to miss in a breed this enthusiastic — our guide to spotting pain in dogs lists the quiet tells.

Which supplements are actually worth it?#

None of them rebuild cartilage, and none come close to the effect of lean body weight. With that said honestly, the evidence tiers look like this.

Omega-3 first, and know what was tested. Three randomised controlled trials give this tier its standing. In 127 dogs across 18 clinics, owners reported significantly improved ability to rise and to play at six weeks and to walk at twelve and twenty-four.^[17] In 38 dogs measured on a force plate, mean peak vertical force improved 5.6% over ninety days against 0.4% in controls, with 82% of treated dogs improving against 38% of controls.^[18] And in 131 dogs on standardised carprofen, the dose came down significantly faster in the supplemented group.^[19]

The caveat you should have before you buy anything: all three trials tested a therapeutic food enriched with fish oil, not a pump bottle of oil, and all three were run with the food manufacturer's involvement.^[17][18][19] A supplement is a reasonable way to reach a similar EPA and DHA intake, and it is what most owners will actually do, but it is an inference from the food trials rather than the thing that was trialled. Ask your vet for a target EPA dose for your dog's weight rather than following the bottle.

Glucosamine and chondroitin second, and the eyes have to be properly open. This is where the honest reading has moved. In a blinded, placebo-controlled trial of 75 dogs with hip osteoarthritis, the glucosamine/chondroitin arm did not separate from placebo on peak vertical force at four weeks, while green-lipped-mussel lipid extracts and carprofen both did.^[20] In a separate 60-dog placebo-controlled trial using continuous activity monitors, there was no difference in activity counts either — while owner-rated pain scores improved equally in both arms, which is what a caregiver placebo effect looks like.^[21]

Two fair defences, which we would rather raise ourselves. Both trials ran roughly 15 to 30 dogs per arm and neither was powered to exclude a small benefit, and the six-week trial used a maintenance dose throughout rather than the manufacturer's loading dose. It is safe and it is inexpensive. But the version of this paragraph that said the evidence is "genuinely mixed" was too kind: the two best-designed trials found nothing, and the thing we are most confident about in this category is a negative result. Give it six weeks, judge it against something you can count — stairs taken, minutes walked — and drop it if you see nothing.

Whether stepping up to Dasuquin is worth it is covered in our Dasuquin vs Cosequin comparison, and matching dose to a Lab-sized body is in the dosing-by-weight guide. And before either: a 6.1% weight loss produced a significant reduction in lameness in obese arthritic dogs, which is more than any supplement on this page has shown.^[22]

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What gear helps a greying Lab?#

Two purchases move the needle most at home, and the free version comes first: rubber-backed runners on the three or four routes your dog actually walks solve most of the traction problem for a fraction of what gear costs.

A 33 kg Labrador with sore elbows lies on the points of those elbows for a large part of the day, and a hard floor loads them directly.^[6] We have seen no published figure for how many hours a day an arthritic dog lies down, so we are not giving you one — the argument for the bed is the pressure, not a statistic. And if the bed you own still springs back under a knuckle pressed at the hip and elbow spots, you do not need a new one yet. The full field, including budget options, is in our orthopedic bed roundup.

The ramp targets the two repeated impacts in a pet Lab's routine that you can actually delete: the couch dismount and the car tailgate. That is a reasoning argument rather than a tested one — no trial has shown a ramp changes joint outcomes — but a Labrador landing front-first from a tailgate is putting the impact through the joint this breed is six times more likely to have disease in.^[3][4] This tri-fold handles Lab weight with margin; for taller vehicles, our ramp guide covers telescoping options.

The bottom line#

The order of operations for a stiff Labrador: weight first, and honestly — run the rib check today and act on what you feel, remembering that a quarter of owners score their dog leaner than the vet does. Movement second, consistent and low-impact, with the fetch habit rationed. Omega-3 third, understanding that what was trialled was a food. Glucosamine fourth and optional, understanding that the two best-designed trials found nothing. Gear where it counts: traction, bed, ramp. Prescription pain control through your vet when the dog needs it, never from your own shelf.

One last number, because it is the reason this page exists. Among 147 Labradors in UK primary care whose cause of death was recorded, musculoskeletal disorder was the most common at 24.5%, ahead of neoplasia at 21.1%, with median longevity 12.0 years.^[6] In this breed the legs are the most common recorded reason the life ends. Not a tumour. The legs — and the single best-evidenced thing you can do about that is free, and it starts at the bowl.

Sources#

1. Pegram C, Woolley C, Brodbelt DC, Church DB, O'Neill DG. "Disorder predispositions and protections of Labrador Retrievers in the UK." Scientific Reports. 2021;11:13988. doi:10.1038/s41598-021-93379-2 — 1,462 Labradors against 20,786 non-Labradors, 2016 VetCompass data; increased odds for 12 of 35 disorders, with osteoarthritis the highest at OR 2.83 (95% CI 2.21–3.62); reduced odds for 7 of 35, lowest patellar luxation OR 0.18.
2. Engdahl K, Malm Persson S, Andersson L, Ringmark S, Bjørnvad CR, Hedhammar Å, Höglund K. "Prevalence of hip and elbow dysplasia in young adult dogs in Sweden." Veterinary Record. 2026;198(12):e560-e573. doi:10.1002/vetr.70224 — Swedish Kennel Club screening 2007–2016, dogs 12–24 months. Labrador hips: 13,125 screened — A 62.7%, B 21.1%, C 11.3%, D–E 4.8%, C–E 16.2%. Labrador elbows: 13,057 screened — ED 0 91.0%, ED 1 5.4%, ED 2 2.0%, ED 3 1.5%, ED 1–3 9.0%. Authors note severe cases may be under-represented because affected young dogs may never be screened.
3. O'Neill DG, Brodbelt DC, Hodge R, Church DB, Meeson RL. "Epidemiology and clinical management of elbow joint disease in dogs under primary veterinary care in the UK." Canine Medicine and Genetics. 2020;7:1. doi:10.1186/s40575-020-0080-5 — 455,069 dogs; one-year period prevalence of elbow joint disease 0.56% (95% CI 0.53–0.60); Labrador Retriever final multivariable OR 5.94 (95% CI 4.65–7.60); of 616 incident cases, osteoarthritis 76.0% and elbow dysplasia 30.8%; of 109 deaths by euthanasia with information available, elbow joint disease contributed to the decision in 41.3%.
4. Humphries A, Shaheen AF, Gómez Álvarez CB. "Biomechanical comparison of standing posture and during trot between German shepherd and Labrador retriever dogs." PLoS ONE. 2020;15(10):e0239832. doi:10.1371/journal.pone.0239832 — 12 Labradors and 12 German Shepherds on a pressure walkway and motion capture; standing, Labradors carried 69% ± 5% of body weight on the forelimbs against 62% ± 2% in German Shepherds (p < 0.001), with the centre of pressure located more cranially.
5. Raffan E, Dennis RJ, O'Donovan CJ, et al. "A Deletion in the Canine POMC Gene Is Associated with Weight and Appetite in Obesity-Prone Labrador Retriever Dogs." Cell Metabolism. 2016;23(5):893-900. doi:10.1016/j.cmet.2016.04.012 — 14 bp deletion in POMC disrupting the β-MSH and β-endorphin coding sequences, allele frequency 12%; associated with body weight (per-allele effect 0.33 SD), adiposity and greater food motivation; among other breeds found only in the flat-coated retriever; significantly more common in Labradors selected to become assistance dogs than pets.
6. McGreevy PD, Wilson BJ, Mansfield CS, Brodbelt DC, Church DB, Dhand N, Soares Magalhães RJ, O'Neill DG. "Labrador retrievers under primary veterinary care in the UK: demography, mortality and disorders." Canine Genetics and Epidemiology. 2018;5:8. doi:10.1186/s40575-018-0064-x — 33,320 Labradors, disorder data from a random sample of 2,074; most prevalent recorded disorders otitis externa 10.4%, overweight/obesity 8.8% (95% CI 7.6–10.1), degenerative joint disease 5.5%; mean adult bodyweight 33.0 kg; median longevity 12.0 years; of 147 deaths with a recorded cause, musculoskeletal disorder 36 (24.5%) and neoplasia 31 (21.1%), with median age at death from musculoskeletal disorder 13.4 years.
7. German AJ, Hervera M, Hunter L, Holden SL, Morris PJ, Biourge V, Trayhurn P. "Improvement in insulin resistance and reduction in plasma inflammatory adipokines after weight loss in obese dogs." Domestic Animal Endocrinology. 2009;37(4):214-226. doi:10.1016/j.domaniend.2009.07.001 — 26 overweight dogs of various breeds through a diet-and-exercise weight-loss programme; body fat mass positively correlated with plasma insulin and insulin:glucose ratio, both of which fell after weight loss; notable decreases in plasma TNF-alpha, haptoglobin and C-reactive protein, indicating improvement of a subclinical inflammatory state.
8. Kealy RD, Lawler DF, Ballam JM, Mantz SL, Biery DN, Greeley EH, Lust G, Segre M, Smith GK, Stowe HD. "Effects of diet restriction on life span and age-related changes in dogs." Journal of the American Veterinary Medical Association. 2002;220(9):1315-1320. doi:10.2460/javma.2002.220.1315 — 48 Labrador Retrievers paired, one of each pair fed 25% less food than its pair-mate from 8 weeks of age until death; food-restricted dogs weighed less with lower body fat and lower serum triglycerides, triiodothyronine, insulin and glucose; median life span significantly longer and onset of chronic disease generally delayed in the restricted group.
9. Lawler DF, Larson BT, Ballam JM, Smith GK, Biery DN, Evans RH, Greeley EH, Segre M, Stowe HD, Kealy RD. "Diet restriction and ageing in the dog: major observations over two decades." British Journal of Nutrition. 2008;99(4):793-805. doi:10.1017/s0007114507871686 — indexed as a randomised controlled trial; "Major lifetime observations included 1.8 years longer median lifespan among diet-restricted dogs, with delayed onset of late life diseases, especially osteoarthritis"; long-term restriction did not negatively affect skeletal maturation, structure or metabolism; restricted dogs required 17% less energy to maintain each lean kilogram.
10. Huck JL, Biery DN, Lawler DF, Gregor TP, Runge JJ, Evans RH, Kealy RD, Smith GK. "A longitudinal study of the influence of lifetime food restriction on development of osteoarthritis in the canine elbow." Veterinary Surgery. 2009;38(2):192-198. doi:10.1111/j.1532-950x.2008.00487.x — same 48-dog cohort; no statistical difference in radiographic elbow osteoarthritis frequency between feeding groups at any time point, no difference in histopathologic prevalence or severity, no difference in gross lesions; severity greater in control-fed dogs at 6 years only; fragmented medial coronoid process, ununited anconeal process and osteochondrosis were absent from every elbow. States "Diet restriction resulted in a 1.8-year extension in median lifespan."
11. Smith GK, Paster ER, Powers MY, Lawler DF, Biery DN, Shofer FS, McKelvie PJ, Kealy RD. "Lifelong diet restriction and radiographic evidence of osteoarthritis of the hip joint in dogs." Journal of the American Veterinary Medical Association. 2006;229(5):690-693. doi:10.2460/javma.229.5.690 — prevalence of radiographic hip osteoarthritis across the cohort rose linearly from 15% at 2 years to 67% by 14 years; median age at first radiographic evidence 6 years in the control-fed group against 12 years in the restricted-fed group; radiographs scored by a board-certified radiologist unaware of group assignment.
12. Salt C, Morris PJ, Wilson D, Lund EM, German AJ. "Association between life span and body condition in neutered client-owned dogs." Journal of Veterinary Internal Medicine. 2019;33(1):89-99. doi:10.1111/jvim.15367 — 50,787 middle-aged neutered dogs across around 900 North American hospitals, including 11,867 Labradors; hazard ratio for death in overweight versus normal body condition, Labrador Retriever 1.83 (99.79% CI 1.54–2.17); overweight condition was associated with shorter life in all twelve breeds studied.
13. Blanchard T, Hoummady S, Banuls D, et al. "The Perception of the Body Condition of Cats and Dogs by French Pet Owners and the Factors Influencing Underestimation." Animals (Basel). 2023;13(23):3646. doi:10.3390/ani13233646 — 304 dogs and 270 cats at vaccination consultations; owner assessments compared against the nine-point body condition score assigned by veterinary personnel; 27% of dog owners underestimated their pet's body condition, and underestimation was associated with the pet actually being overweight.
14. O'Neill DG, Khoo JSP, Brodbelt DC, Church DB, Pegram C, Geddes RF. "Frequency, breed predispositions and other demographic risk factors for diagnosis of hypothyroidism in dogs under primary veterinary care in the UK." Canine Medicine and Genetics. 2022;9(1):11. doi:10.1186/s40575-022-00123-8 — 905,553 dogs, 2,105 recorded with hypothyroidism in 2016; annual prevalence 0.23% (95% CI 0.22–0.24); 24 predisposed and nine protected breeds identified; Labrador Retriever multivariable OR 1.40 (95% CI 1.16–1.68, p < 0.001), against Standard Doberman Pinscher 17.02 and Tibetan Terrier 11.25 at the top; median age at first diagnosis 7.65 years.
15. Travail V, Fernandez Sanchez C, Costo JM, et al. "Assessment of the likelihood of hypothyroidism in dogs diagnosed with and treated for hypothyroidism at primary care practices: 102 cases (2016-2021)." Journal of Veterinary Internal Medicine. 2024;38(2):931-941. doi:10.1111/jvim.16993 — 102 dogs already receiving levothyroxine in first-opinion practice, reviewed independently by three ECVIM-CA diplomates; each judged levothyroxine supplementation not indicated in 58.8%, 52.9% and 45.1% of cases respectively; authors conclude hypothyroidism may be over-diagnosed and that thyroid testing should be reserved for dogs with a high pre-test probability.
16. Witsberger TH, Villamil JA, Schultz LG, Hahn AW, Cook JL. "Prevalence of and risk factors for hip dysplasia and cranial cruciate ligament deficiency in dogs." Journal of the American Veterinary Medical Association. 2008;232(12):1818-1824. doi:10.2460/javma.232.12.1818 — 1,243,681 dogs reported to the Veterinary Medical Database 1964–2003; castrated males OR 1.21 for hip dysplasia, castrated males OR 1.68 and spayed females OR 2.35 for cruciate deficiency; dogs over 4 years more likely to have cruciate deficiency; large and giant breeds more likely to have either. Breed-specific figures sit in full text we could not obtain, so no Labrador-specific cruciate figure is quoted on this page.
17. Roush JK, Dodd CE, Fritsch DA, Allen TA, Jewell DE, Schoenherr WD, Richardson DC, Leventhal PS, Hahn KA. "Multicenter veterinary practice assessment of the effects of omega-3 fatty acids on osteoarthritis in dogs." Journal of the American Veterinary Medical Association. 2010;236(1):59-66. doi:10.2460/javma.236.1.59 — randomised, double-blinded, controlled clinical trial; 127 client-owned dogs with osteoarthritis at 18 privately owned clinics fed for 6 months on a test food with a 31-fold increase in total omega-3 content; owners reported significantly improved ability to rise and to play at 6 weeks and to walk at 12 and 24 weeks. The intervention was a food, and several authors were employed by the food manufacturer.
18. Roush JK, Cross AR, Renberg WC, Dodd CE, Sixby KA, Fritsch DA, Allen TA, Jewell DE, Richardson DC, Leventhal PS, Hahn KA. "Evaluation of the effects of dietary supplementation with fish oil omega-3 fatty acids on weight bearing in dogs with osteoarthritis." Journal of the American Veterinary Medical Association. 2010;236(1):67-73. doi:10.2460/javma.236.1.67 — randomised, double-blinded, controlled clinical trial; 38 dogs at 2 university clinics, test food containing 3.5% fish oil omega-3 fatty acids; change in mean peak vertical force from day 0 to day 90 was 5.6% in the test group against 0.4% in controls; improvement in peak vertical force seen in 82% of test dogs against 38% of controls.
19. Fritsch DA, Allen TA, Dodd CE, Jewell DE, Sixby KA, Leventhal PS, Brejda J, Hahn KA. "A multicenter study of the effect of dietary supplementation with fish oil omega-3 fatty acids on carprofen dosage in dogs with osteoarthritis." Journal of the American Veterinary Medical Association. 2010;236(5):535-539. doi:10.2460/javma.236.5.535 — randomised, controlled, multisite trial; 131 dogs at 33 hospitals standardised to approximately 4.4 mg/kg/day carprofen, then randomised to a fish-oil-supplemented food or a low-omega-3 control food; carprofen dosage decreased significantly faster in the supplemented group over 12 weeks.
20. Kampa N, Kaenkangploo D, Jitpean S, Srithunyarat T, Seesupa S, Hoisang S, Yongvanit K, Kamlangchai P, Tuchpramuk P, Lascelles BDX. "Study of the effectiveness of glucosamine and chondroitin sulfate, marine based fatty acid compounds (PCSO-524 and EAB-277), and carprofen for the treatment of dogs with hip osteoarthritis." Frontiers in Veterinary Science. 2023;10:1033188. doi:10.3389/fvets.2023.1033188 — prospective, block-randomised, double-blinded, placebo-controlled trial; 75 pet dogs with hip osteoarthritis in five arms of 15. At 4 weeks, change in peak vertical force was significant and greater than placebo for PCSO-524, EAB-277 and carprofen but not for glucosamine/chondroitin (−0.05 ± 6.34 against placebo 0.08 ± 1.90); at 6 weeks the glucosamine group's change (1.08 ± 5.49) lay between placebo and the other treatments. Subjective orthopaedic assessment scores did not change significantly in any group, including carprofen. Funded by Pharmalink International Ltd, which owns the EAB-277 and Antinol trademarks.
21. Scott RM, Evans R, Conzemius MG. "Efficacy of an oral nutraceutical for the treatment of canine osteoarthritis. A double-blind, randomized, placebo-controlled prospective clinical trial." Veterinary and Comparative Orthopaedics and Traumatology. 2017;30(5):318-323. doi:10.3415/vcot-17-02-0020 — 30 dogs on a glucosamine/chondroitin nutraceutical against 30 on placebo, wearing activity monitors continuously across a 97-day study; no difference between groups in daily activity counts; owner-assessed pain interference and pain severity improved over 90 days in both groups with no difference between them, which the authors attribute to a caregiver placebo effect.
22. Marshall WG, Hazewinkel HA, Mullen D, De Meyer G, Baert K, Carmichael S. "The effect of weight loss on lameness in obese dogs with osteoarthritis." Veterinary Research Communications. 2010;34(3):241-253. doi:10.1007/s11259-010-9348-7 — 14 obese client-owned dogs with clinical and radiographic osteoarthritis on a restricted-calorie diet over 16 weeks; significant decrease in lameness from a weight loss of 6.10% onwards, supported by kinetic gait analysis from 8.85% onwards. Open prospective trial, no control group.

This article is educational and does not replace veterinary advice. Diagnosis, pain medication and any large weight-reduction plan belong with your own vet, who can weigh your dog, score body condition properly and rule out the other things that make a middle-aged Labrador slow down.