Arthritis in Horses (DJD): Causes, Treatment & Management

30 September 2025

Arthritis in horses, known clinically as degenerative joint disease (DJD) and in its most common form as osteoarthritis (OA), is the single biggest musculoskeletal cause of lameness. The UC Davis Centre for Equine Health estimates that osteoarthritis accounts for more than 60 per cent of all equine lameness, and the British Horse Society describes it as causing reduced performance, pain and lameness, seen most commonly in elderly horses after years of wear and tear. The disease is progressive, non-curable and ultimately irreversible, but it is also one of the most manageable chronic conditions in the modern yard, provided owners catch it early and stay ahead of the wear curve.

This guide explains what arthritis in horses actually is, the early signs to watch for in the front and back legs, how vets diagnose it, the realistic treatment options (NSAIDs, joint injections, IRAP, PRP, supplements and surgery), and the day-to-day management that makes the biggest difference to a horse’s working life.

What is arthritis in horses (DJD)?

Arthritis in horses is inflammation of a joint. Degenerative joint disease, written as DJD or equine DJD, is the chronic, progressive end-stage of that inflammation: a slow deterioration of a synovial joint characterised by the loss of articular cartilage, inflammation of the synovial membrane, and remodelling of the underlying bone. In a healthy joint, the ends of the bones are capped with smooth, glassy hyaline cartilage and bathed in lubricating synovial fluid. Once that cartilage is damaged, it cannot regenerate. Bone-on-bone friction follows, the joint capsule fibroses, new bone (osteophytes) forms around the joint margins, and the result is the chronic, low-grade pain owners recognise as “stiffness” and vets recognise as lameness.

Osteoarthritis is the most common form of DJD in horses, and the two terms are often used interchangeably. The British Horse Society describes arthritis simply as inflammation of a joint or joints; DJD is what that inflammation becomes once cartilage damage is established.

Types of arthritis in horses

Osteoarthritis (OA / DJD): the wear-and-tear progressive form, by far the most common
Traumatic arthritis: joint inflammation following acute injury, often a precursor to DJD if left untreated
Septic (infectious) arthritis: bacterial joint infection, usually after a puncture wound or post-injection contamination. Treat it as an immediate emergency and phone the vet the moment you suspect it. There is no safe waiting period: the American College of Veterinary Surgeons describes the infection causing “rapid deterioration of the articular cartilage”, calls the condition life-threatening and says “rapid identification and treatment is paramount for survival and long-term soundness”. No source supports the widely repeated idea of a 48-hour grace period, and a wound near a joint should never be left to be looked at in the morning
Juvenile arthritis: develops in young horses, often linked to osteochondrosis (OCD) or developmental orthopaedic disease

Which joints are most commonly affected?

Equine DJD has clear favourite sites that reflect the load each joint carries. Knowing which joint is involved helps interpret the lameness and predict the prognosis.

Distal hock joints (bone spavin): the small joints at the bottom of the hock, arguably the single most common site of DJD in older sport horses, particularly dressage horses and showjumpers. See our full guide to bone spavin, and note that soft swelling of the joint capsule is instead bog spavin
Coffin (distal interphalangeal) joint: within the hoof, common in horses worked on hard surfaces. Our article on the anatomy of the coffin joint explains why this forefoot joint is so vulnerable
Pastern joint (high ringbone): DJD here causes characteristic bony enlargement of the pastern. The related bony change of the pedal bone wings is sidebone
Fetlock joint: a high-motion joint, frequent in racehorses and event horses. See our entry on the fetlock
Knee (carpal) joint: chip fractures and OA are common in racehorses
Stifle: the large joint comparable to the human knee; medial femorotibial OA is a common ageing change and a frequent cause of hindlimb lameness
Cervical (neck) facet joints: an increasingly recognised cause of forelimb lameness, poor performance and behavioural change
Sacroiliac joint: pelvic discomfort presenting as hindlimb lameness or a horse that “won’t go forward”. See sacroiliac joint disease

Causes and risk factors of arthritis in horses

DJD is rarely caused by a single event. It develops from the cumulative loading of joints over time, accelerated by specific risk factors.

Age: risk rises with age, but there is no birthday at which it jumps. The British Horse Society’s position is that horses can develop arthritis at any age while it is most commonly seen in elderly horses, and in a UK study of 200 horses aged 15 and over, vets found lameness in 50% of them when owners had reported it in only 23% (Ireland and others, Equine Veterinary Journal 2012, PMID 21696434). Competition horses can show changes much earlier
Workload: repetitive concussion on hard ground, tight turns and high-impact disciplines (racing, eventing, polo) accelerate cartilage wear
Conformation: long or upright pasterns, base-narrow or base-wide stance, sickle hocks and offset knees all concentrate load abnormally
Previous injury: chip fractures, ligament strains and joint sepsis dramatically raise DJD risk in that joint
Obesity: every extra kilogram is amplified through the limb at speed, and native breeds prone to weight gain are particularly vulnerable
Breed and bodyweight: there is no good evidence for a sweeping breed predisposition. UC Davis states that osteoarthritis can affect horses of any age and breed, and the breed associations that are actually published are narrow rather than general, such as the severe carpometacarpal OA reported mainly in older Arabian horses (Veterinary Surgery 2003, PMID 12784194). What a heavy Clydesdale or Shire does put through a joint is more absolute force, because peak joint load scales with body mass
Poor farriery: long toes, low heels, mediolateral imbalance and infrequent shoeing cycles distort joint loading
Surface: both rock-hard summer ground and deep, holding mud are problematic; consistent, well-maintained synthetic surfaces are kinder
OCD lesions: developmental cartilage flaws in young horses commonly progress to DJD if not addressed

Early signs of arthritis in horses

The earliest signs of arthritis in horses are often subtle behavioural changes that owners explain away as “having a cold day”. Recognising them early, before structural damage is advanced, is the single most effective thing an owner can do.

Stiffness on first leaving the stable that rides out within 10 minutes: the textbook early sign
Reluctance to pick up a particular canter lead, or struggling on circles in one direction
Resistance to going forward, a hollow back, refusing fences, or bucking on transitions
Difficulty for the farrier: unwilling to hold up a particular leg
Visible joint thickening: windgalls, capped hocks, or palpable enlargement of the fetlock, pastern or hock
Heat in the joint: mild but consistent warmth compared to the opposite limb
Performance plateau or decline: losing time across country, lower marks for paces in dressage
Behavioural change: grumpy in the stable, ear-pinning when girthed, difficulty mounting

Signs of arthritis in the front legs often show as shortened, pottery strides, stumbling and reluctance to work downhill, while signs of arthritis in the back legs more commonly appear as a loss of hindlimb push, difficulty striking off on the correct canter lead and struggling to hold a hind foot up for the farrier. The classic clinical presentation is a horse that warms out of stiffness: stiff for the first 5 to 10 minutes, then moving freely once the joints are warm and lubricated, and stiff again the following morning.

How vets diagnose arthritis and DJD in horses

Modern equine ambulatory practice has the kit to diagnose DJD accurately on most yards. A typical work-up follows this sequence:

Lameness history and conformation assessment, including age, discipline, recent surfaces and previous problems
Static and dynamic examination: palpation for heat, swelling and pain on flexion; a trot-up in hand and on the lunge on hard and soft surfaces; and a ridden assessment
Flexion tests: held flexion of the suspect joint for 30 to 60 seconds, then an immediate trot away, where positive flexion exacerbates the lameness
Diagnostic analgesia (nerve and joint blocks): local anaesthetic placed sequentially up the limb to localise the pain to a specific joint
Radiography (X-ray): shows bony changes such as osteophytes, joint-space narrowing, subchondral bone sclerosis and periarticular new bone
Ultrasonography: soft-tissue assessment of the joint capsule, ligaments and surrounding tendons
MRI: the gold standard for early DJD, as it shows cartilage and subchondral bone marrow oedema before X-ray changes appear. Standing low-field MRI is now widely available in the UK
Synoviocentesis (joint tap): analysis of synovial fluid to check total protein and nucleated cell counts, which also rules out septic arthritis
Computed tomography (CT): increasingly used for cervical and complex hock DJD

It is worth distinguishing DJD from other causes of foot and limb lameness that can mimic it, such as navicular disease and laminitis, which is exactly why localising nerve blocks matter so much.

Treatment options for arthritis in horses

Cartilage damage cannot be reversed, so the aim of treating arthritis in horses is three-fold: relieve pain, slow further deterioration, and maintain working soundness for as long as possible. A modern protocol blends pharmacological, regenerative and management approaches.

1. Non-steroidal anti-inflammatory drugs (NSAIDs)

NSAIDs are the workhorse of DJD pain management. UK options include:

Phenylbutazone (Equipalazone, “bute”): the cheapest and most widely used. It is prescription-only, and the dose goes by bodyweight, not by the horse. The UK licensed regime for a 450kg horse (Equipalazone 1g oral powder Summary of Product Characteristics, VMD Product Information Database, revised February 2025) is 2g twice on day one (8.8mg/kg/day), then 1g twice daily for four days (4.4mg/kg/day), then 1g daily or on alternate days (2.2mg/kg/day). For a 225kg pony it is a single 1g sachet on alternate days. The SPC warns that “the therapeutic index of phenylbutazone is low. Do not exceed the stated dose or the duration of treatment”, and says to stop if there is no response after four to five days. Do not treat “2 to 4g a day” as a working dose: 4g is the day-one loading dose for a full-sized horse, and in a pony it is a serious overdose
Meloxicam (Metacam, Inflacam): better gastric tolerance, useful for older horses or those with previous gastric ulceration
Firocoxib (Equioxx): COX-2 selective, with a superior gastric and renal safety profile; expensive but increasingly the long-term choice
Flunixin (Finadyne): short-term flare-up management

NSAIDs do not slow disease progression; they manage pain and allow continued exercise. Long-term use carries gastric ulcer and renal risks, so periodic monitoring with a vet is sensible.

2. Intra-articular joint injections

Direct injection into the affected joint delivers high concentrations of medication exactly where they are needed.

Corticosteroids: methylprednisolone (Depo-Medrone V), triamcinolone or betamethasone deliver a potent anti-inflammatory effect. Horse & Hound‘s guide to equine joint injections, written with equine surgeon Thijs de Bont MRCVS, names triamcinolone and betamethasone as the two most commonly used. Of the three, only the methylprednisolone product holds a UK veterinary licence, so the others are given under the prescribing cascade; the human triamcinolone brand Adcortyl is discontinued in the UK. They are widely used but carry concerns about cartilage health from repeated dosing and a recognised laminitis risk in horses with metabolic disease
Hyaluronic acid (HA): replaces the lubricating component of synovial fluid, commonly combined with a steroid
Polysulphated glycosaminoglycan (Adequan): given intramuscularly or intra-articularly, with modest evidence for cartilage support
Pentosan polysulfate: a disease-modifying osteoarthritis drug (DMOAD), injectable and increasingly used in the UK

3. Regenerative therapies

The newer biologics use the horse’s own blood or bone marrow to deliver concentrated anti-inflammatory mediators or cells.

IRAP (Interleukin-1 Receptor Antagonist Protein): autologous serum incubated with glass beads to harvest IL-1 antagonists, then injected into the joint over a series of treatments
Platelet-rich plasma (PRP): concentrated platelets release growth factors
Stem cells: bone marrow or fat-derived, mostly used for tendon and ligament injuries but increasingly for severe joint disease
Pro-Stride and similar combination products: combine concentrated platelets and IRAP from a single blood draw

Cost in the UK ranges from roughly £400 to £1,200 per joint depending on the therapy and clinic, but the procedure can extend a horse’s career significantly when conventional joint medications have stopped working.

4. Bisphosphonates

Tiludronic acid (Tildren) and clodronic acid (Osphos) inhibit bone resorption, and both are UK-authorised, but their licences are narrower than they are usually described. Tildren is licensed only as an aid in treating lameness associated with bone spavin, in combination with a controlled exercise regime; Osphos only for forelimb lameness associated with bone resorption in the navicular bone in adult horses (Summaries of Product Characteristics, VMD Product Information Database, revised June 2024 and July 2025 respectively). Neither holds a general licence for DJD with subchondral bone involvement. They are not first-line agents, and both are contraindicated in young horses: Tildren must not be given to a horse under 3 years old, Osphos to a horse under 4.

5. Surgical options

Arthroscopy: minimally invasive joint surgery to remove cartilage flaps, bone chips or osteophytes
Surgical arthrodesis: deliberate fusion of low-motion joints (the small distal hock joints, the pastern joint) eliminates motion and therefore pain, producing career-saving soundness in the right candidates
Chemical arthrodesis: injection of sodium monoiodoacetate or ethanol to fuse the small distal hock joints, a cheaper alternative to surgical fusion in selected cases (monoiodoacetate in 104 horses, Australian Veterinary Journal 2004, PMID 15088956; ethanol in 24 horses, Equine Veterinary Journal 2012, PMID 22128830). It is not a general technique for any low-motion joint: when monoiodoacetate was trialled in the pastern joint the authors concluded it “cannot be advocated in clinical cases because of the high complication rate and lack of bony fusion” (Canadian Journal of Veterinary Research 2000, PMID 11041498)

6. Joint supplements and nutraceuticals

The supplement market for equine joints is enormous and the evidence base is highly variable. Products with the most credible peer-reviewed support include:

Glucosamine and chondroitin sulphate: modest in-vitro and clinical evidence, widely used as low-cost daily support
MSM (methylsulfonylmethane): some evidence as an adjunct anti-inflammatory
Hyaluronic acid (oral): limited but emerging evidence
Omega-3 fatty acids: anti-inflammatory action, well supported in other species and increasingly recommended in horses
Avocado-soybean unsaponifiables (ASU): emerging evidence for cartilage support
Green-lipped mussel: a rich source of chondroitin and omega-3s, with reasonable clinical reports

Look for products that publish their dosing and ingredient quantities, and choose BETA NOPS-accredited suppliers if you compete.

Natural and at-home management of an arthritic horse

Owners often ask how to treat arthritis in horses naturally. There is no herbal cure, but several drug-free measures genuinely reduce pain and slow progression, and they form the backbone of any long-term plan alongside veterinary treatment.

Consistent low-intensity movement rather than box rest, to keep joints lubricated
Weight control to take load off the joints, the single most powerful drug-free intervention
Warmth and dryness: arthritic horses are noticeably stiffer in cold, damp conditions, so rugs and dry standing help. Heat retention is also the most plausible explanation for what owners observe from magnetic therapy rugs and boots, because the controlled equine trials found the warming was identical with and without the magnets
Turnout on good, level footing so the horse keeps moving without jarring or slipping
Omega-3 and green-lipped mussel as naturally derived anti-inflammatory feed additions

Day-to-day management of an arthritic horse

Medical treatment buys you the window; daily management decides how big that window is.

Exercise: keep them moving

Complete rest is rarely the right answer for a horse with DJD. Joints stay healthier with regular, low-intensity, controlled movement than with prolonged stabling. The aim is consistent gentle work: daily turnout, in-hand walks, and hacking on straight lines and good surfaces, with high-impact and tight-turn work reduced.

A 20-minute walking warm-up before any trot or canter work
A 10-minute walking cool-down at the end
Avoid prolonged stabling, with turnout 24/7 wherever the field surface allows
Reduce or eliminate jumping, sharp lateral work and tight turns in late-stage disease
Vary surfaces but avoid working on rock-hard ground or deep mud whenever possible

Farriery

Trim and shoe at 5 to 6 week cycles rather than waiting 8 weeks. Discuss balance, breakover and any therapeutic shoeing options with a Registered Shoeing Smith. Common interventions include rolled toes, wider-web shoes for fetlock OA, and lateral or medial extensions for ringbone.

Weight

Measured on a force plate, a sound horse at trot loads a single forelimb at a peak of 11.59 newtons per kilogram of bodyweight and a hindlimb at 10.21 N/kg (Merkens and Schamhardt, Equine Veterinary Journal 1993, PMID 8467772), which is roughly 1.2 and 1.0 times the horse’s own bodyweight through one limb, every stride. Every extra kilogram is therefore paid for at more than its own weight, and that is the mechanical case for keeping an arthritic horse lean. Aim for a body condition score of 5 out of 9; 7 or above is classed as obese (PMID 30058970). Be honest about what weight loss buys, though. No equine trial has yet shown that it improves lameness scores on its own, and the one study to measure body condition and lameness grade together opened by noting that the relationship between obesity and equine degenerative joint disease “has not been explored” (Journal of Animal Physiology and Animal Nutrition 2018, PMID 29707811). Use a weigh tape or weighbridge regularly.

Stable and field environment

Deep, supportive bedding, such as rubber mats with shavings or straw
Avoid hard concrete-only standing
A field with reasonable footing, neither boggy in winter nor rock-hard in summer
Quiet companions, because turning an arthritic horse out with a youngster who chases it is counterproductive

Physiotherapy and complementary therapies

Equine physiotherapy, massage, chiropractic and acupuncture all have growing evidence bases when delivered by an ACPAT-qualified physiotherapist or an RCVS-certified vet. Hydrotherapy via an underwater treadmill is particularly useful for low-impact loading and is now widely available across the UK.

Prognosis for horses with arthritis

The realistic expectation for a horse diagnosed with mild-to-moderate DJD, given appropriate treatment and management, is several more years of active work, often at a slightly reduced level. Bone spavin in particular frequently fuses naturally in older horses, leaving them sound at the trot. Severe end-stage DJD with marked structural change carries a guarded prognosis for ridden work, but most horses can enjoy an active retirement at grass with NSAID support.

The single biggest determinant of long-term outcome is how early the disease is recognised and addressed. Subtle stiffness ignored for two seasons becomes severe DJD that no amount of joint medication will fully resolve.

Prevention: keeping young joints healthy

Slow, progressive training, because building bone, ligament and cartilage takes years rather than weeks
Avoid prolonged work on hard, jarring surfaces
Prompt veterinary investigation of any new lameness
Address conformational concerns through corrective farriery from a young age
Maintain an ideal bodyweight throughout life, with routine 5 to 6 week farrier cycles
Regular vet check-ups, including dental and back assessment
Consider prophylactic joint supplements in mid-career sport horses

FAQs about arthritis and DJD in horses

Can a horse with arthritis still be ridden?

Yes, in most cases. The British Horse Society’s arthritis guidance says exercise, as advised by your vet, can be beneficial in reducing stiffness and that long periods stabled should be avoided. It also warns that doing too much can cause further joint damage, and that in some cases box or field rest is what the vet will recommend first. The workload is a veterinary decision rather than a rule of thumb. The usual exceptions to ridden work are an acute flare-up, the period after a joint injection, for which your vet will set the rest interval, and severe end-stage disease where ridden work is no longer humane.

How long can a horse live with arthritis?

With good management, a horse diagnosed with DJD in mid-life can live a normal lifespan, into the late 20s and beyond, with several useful years of ridden work. Age at diagnosis, the joint affected, severity and management quality all influence the trajectory.

How do you treat arthritis in horses naturally?

There is no herbal cure, but drug-free measures that genuinely help include weight control, consistent low-impact movement, keeping the horse warm and dry, turnout on good footing, and naturally derived anti-inflammatory supplements such as omega-3 oils and green-lipped mussel. These work best as a complement to, not a replacement for, veterinary treatment and good farriery.

What is the best supplement for an arthritic horse?

No single supplement has overwhelming evidence above the others. The combination with the strongest support is glucosamine plus chondroitin plus MSM, with added omega-3s. Look for transparent ingredient lists with quantities, BETA NOPS accreditation if you compete, and remember that supplements are an adjunct rather than a replacement for veterinary treatment, farriery and management change.

Is DJD the same as ringbone?

Ringbone is DJD specifically of the pastern joint (high ringbone) or coffin joint (low ringbone), characterised by visible bony enlargement around the pastern. The disease process is the same; only the location and visible appearance differ.

What is the lameness grading scale?

The American Association of Equine Practitioners (AAEP) lameness scale runs from 0 to 5. Grade 0 is lameness not perceptible under any circumstances. Grade 1 is difficult to observe and not consistently apparent, regardless of circumstances. Grade 2 is difficult to observe at a walk or when trotting in a straight line, but consistently apparent under certain circumstances such as circling, inclines or a hard surface. Grade 3 is consistently observable at a trot under all circumstances. Grade 4 is obvious at a walk. Grade 5 produces minimal weight-bearing in motion or at rest, or a complete inability to move. Most DJD lameness is picked up at Grades 1 to 3. Two points are easy to get wrong: what defines Grade 2 is not that the lameness is mild but that it only shows under certain circumstances, and a lameness that is obvious at the walk is already Grade 4.