Degenerative Joint Disease (DJD) is another name for osteoarthritis, the most common type of arthritis in horses (as well as in many other animals and humans). It is one of the most common diseases equine vets treat on a day-to-day basis in the UK. More than 41% of all lameness was reported to be the result of DJD in 2016 and it was the second most common cause of lameness in horses used for leisure riding, highlighting that it is not only a condition only of older horses (NEHS, 2016).
Many vets prefer the term DJD because it neatly sums up what the disease involves: joint degeneration. Although DJD is not curable, its progress can be slowed. By understanding the disease we are better placed to monitor our horses’ joint health, spot symptoms sooner and prolong comfort and function with the help of our vet and farrier.
Hocks, fetlocks and knees are common hotspots for the disease, in part because even mild DJD will have a profound effect, whereas DJD in less mobile joints may be more advanced before symptoms are noticed. DJD is most common in hocks, responsible for more than 15% of all lameness issues (NEHS, 2016).
Degeneration occurs when inflammatory substances are released into the joint capsule, causing deterioration of cartilage, underlying bone and joint fluid.
DJD may be the result of:
General wear and tear – the reason DJD is very common in older horses
Uneven weight-bearing (due to poor conformation, hoof imbalance or other health problems)
Osteochondrosis dissecans (OCD) - a disease causing malformation of cartilage
We can support a horse's joint health through lifelong weight management, keeping the horse fit, warming up and down as part of exercise, and offering the horse plenty of turnout on well-drained paddocks.
Working with a good farrier will make a big difference to optimising hoof balance and helping joints cope with impact that is exerted upon them as the horse moves.
The earlier DJD is spotted, diagnosed and managed, the better. Many conditions share symptoms with DJD so it is important the horse is examined by a vet for an accurate diagnosis. Look out for:
Lameness (may not be obvious if more than one limb is affected)
Pain on flexion/decreased joint mobility
New bone formation
Handling issues/changes (for example uncharacteristic resistance to leg handling)
If your horse is diagnosed with DJD, don’t panic! Monitoring and tailored management can really help slow the progress of the disease and keep your horse comfortable for longer:
Ensure your horse is not overweight
Opt for level, mud-free paddocks if possible
Provide shelter and rugs in winter
Raise feeding points if DJD affects your horse’s front legs or neck
Allow your horse plenty of turnout to promote gentle exercise
Take care when introducing any new field companions
Ensure stables and shelters are well bedded and banked to help your horse lie down and get up more easily
A horse with mild DJD can often still be worked but expectations should be reviewed with your vet (jumping has more impact on joints than flatwork, for example)
Your horse will benefit from extended warm-ups and cool-downs as part of exercise routines
Your vet and farrier should work closely together if a horse is diagnosed with DJD
Treatments range from intra-articular injections (especially if only one joint is affected) through to daily medication with a non-steroidal anti-inflammatory drug for more generalised DJD. Although side effects are possible when using anti-inflammatory drugs they are relatively rare and the risk will be minimised by sensible dosing as advised by your vet. Surgery may also be advised in special cases.
Monitoring a horse with DJD is essential. Factors such as weather, activity levels and other health conditions can all affect symptoms. Work with your vet to provide additional support when needed, usually in winter. Arrange regular veterinary reviews to help monitor your horse’s long-term progress. A video diary can also be invaluable.
Remember that even with treatment and management, symptoms of DJD will inevitably worsen over time. Once treatments can no longer control joint pain, euthanasia will sadly be the most humane outcome to ensure DJD does not cause the horse to suffer unnecessarily.