Arthritis is often thought of as a natural part of ageing, both in humans and in horses and other animals. This is partly because its outwards signs tend to show up later in life.
But in horses, although advancing age is a risk factor, unfortunately osteoarthritis is diagnosed fairly commonly in young horses as well.
In many cases, the factors that lead to the condition are at play for many years before, in the way that a horse is managed, fed and ridden. In fact, decisions made about a horse’s care at every phase of life life will ultimately affect if, when and to what extent he or she develops arthritis.
This means that regardless of your horse’s age, you can take steps now to protect the heath of his or her joints. Most of these measures are not expensive or difficult, but require consistency and vigilance of care on your part, as well as restraint.
Although the normal wear and tear of an active life, as well as the horse’s own genetics, may make arthritis unavoidable, you will be able to minimise the impact of the condition on your horse’s soundness, activity level and enjoyment of life.
It’s probably fair to say that every horse who leads an active life is going to get some degree of arthritis if he or she lives long enough… but thoughtful care throughout his life can keep it at a manageable level. And if you are fortunate enough to have a foal or a weanling in your care, it’s definitely worth the effort.
Osteoarthritis can have lots of triggering causes, all with the same end-result: inflammation, pain, swelling, bony changes in the joint and reduced range of motion of the joint.
CAUSES OF ARTHRITIS IN HORSES
- Trauma: Any type of loading or weight bearing can cause a degree of trauma to the joint. The various areas of the joints in the front and hind limbs are affected differently, with different types of loading. To explain this, we can appreciate that the joints are under a low-level constant loading during standing, an intermittent loading during walking and a very high and sudden loading in things like galloping, jumping, barrel racing and certain dressage movements. If the joints are not aligned optimally to withstand the loading, or if the tissue of the joints, ligaments, tendons and muscles are not strong enough for the amount of loading applied, then there will be more trauma to the joint. It is this trauma, whether sudden and strong or continuous and low-grade that leads to inflammation and changes in the joint which results in OA.
- Poor conformation: This put uneven weight bearing across a joint, increasing the loading and trauma in certain areas of the joint.
- Overwork: Working too much or for too long on hard surfaces increases trauma because of concussion.
- Poor foot balance: Incorrect trimming and shoeing can again result in less than ideal load bearing, focussing trauma in one area of the joint
- Joint disease: Any joint disease, such as OCD as a youngster, can result in inflammation
- Direct damage to a joint: Trauma from an accident can affect the stabilising ligaments or the joint itself
- Infection of a joint can also lead to osteoarthritis.
- Genetics
- Increasing age
Foals and weanlings
Age: birth to 24 months
It is amazing watching foals and youngsters playing out in the paddock. They race around leaping, twisting and turning. It is easy to start to dream about the type of horse we want them to mature into. We certainly don’t associate problems like arthritis with such young, beautiful, athletic animals.
However, it is very important that even at this young age, every care is taken to try and prevent or delay the onset of osteoarthritis in the future.
We can start this prevention before the foal is even born. The broodmare requires optimum nutrition for many reasons, and one of these is to aid good bone and joint formation in the developing foal, and try and prevent the joint condition osteochondritis dissecans (OCD).
A broodmare should be fed the correct levels of vitamins and minerals, particularly copper, although others are important too.
Once the foal is born we need to take care of its joints. Take a good look at the foal’s legs to see if they are straight, with no conformational problems. If you have any concerns at all, talk to your veterinarian sooner rather than later – some problems can be corrected early on life.
If a young foal becomes sick, call your veterinarian urgently as sick foals often have bacteria in their blood stream. The bacteria can settle in a joint causing a joint infection which if not treated rapidly will lead to the development of osteoarthritis even if the infection is cured. Don’t delay; a sick young foal needs treating urgently.
As the foal grows and is weaned, don’t be tempted to overfeed it with hard feed. Rapid growth of young horses has been associated with the joint problem OCD, as has large body size in a young horse and being fed diets high in energy or without a good balance of vitamins and minerals. Also, as in any species (including humans!), carrying extra weight puts extra strain on joints.
If your foal/youngster does need to have surgery for OCD make sure you follow the discharge instructions carefully including giving any joint supplements that may be recommended.
Teach your foal to pick up its feet and get used to having its hooves trimmed. It is important for the developing bones and joints that the feet are well balanced (if there was a conformation problem this may have been able to have been fixed with corrective trimming while the foal was still young, but if this is left too long it will be too late).
If the foal has been taught well and behaves to have its feet trimmed, it makes it more likely that they will be done regularly as the foal matures. We all know if something is easy we will do it, but it we are dreading holding our crazy two-year-old colt while he makes a big performance that he can’t possibly stand on only three legs and thinks the rasp is an instrument of torture, then we will probably keep putting it off!
Here in New Zealand, our foals are usually kept outside and get plenty of natural exercise. Ideally, young horses are turned out in large paddocks with lots of natural variation for them to get used to; hills, streams, trees, uneven ground etc. Exercise is very important as it strengthens the bones, muscles, tendons and ligaments but of course carries the risk of injury. If we are focussing on preventing OA then we also need to be keeping a close eye on our youngsters to look for any signs of lameness, any swelling of a joint or around a joint. Any injury to the joints or a swollen joint needs to be treated urgently and appropriately and anti-inflammatory measures put in place as soon as possible eg. ice, rest etc.
Young horses
Age: two to five years
In this age group, ridden work is started and there is lots of discussion around when the best time is to start a horse under saddle.
Most racehorses will be well into their training and race career at a comparatively young age. There are several studies that have shown a benefit of early exercise on bones and joints, as exercise aids the development of the bone to withstand the loads being applied. But we also have the risk of damage to joints unable to withstand the extreme forces.
Research is ongoing as to the effects of a high workload at a young age. (Racing itself does put a high level of load-bearing on the joints whatever the horse’s age, and may speed up natural age-related changes).
For sporthorses, it is more common to wait until they are a little older until we give them a high workload, particularly with slow-maturing warmbloods.
There is a difference in terms of the effects on the joints between being handled, introduced to a saddle, bridle and rider and going for quiet hacks to training for and competing in competitions.
So while it can feel like you’re being left behind waiting for your horse to mature physically enough so you can crack in to his or her competition career, there are plenty of ways to begin training without mounting, or without undue risk to growing joints.
Through groundwork, you can have him or her responding to basic commands and understanding how to yield to pressure, and these lessons will transfer to work under saddle once you do get on.
When mounted work does begin, you need to condition a young horse just as carefully – or even more so – as you would a mature horse coming back from injury. This means short, easy workouts to start with, slowly building up to longer or more intensive sessions, with regular days of rest and turnout.
Be mindful of the torque associated with tight turns; keep circles large and few, and avoid lungeing for more than a few minutes at a time. Resist the urge to drill a young horse over and over.
What we definitely want to avoid is a rapid transition from a young horse grazing peacefully in a paddock to working hard in circles in the arena or over jumps in a very short time frame. Bones, tendons and ligament do adapt to the exercise they are being asked to do, but it takes time for these changes to happen, and joints won’t be as well supported until these changes have taken place.
A high workload, the surface the horse is worked on (eg. hard concussive surface) and the work it is asked to do (eg. higher jumps, difficult work) are all important factors in the risk of developing osteoarthritis.
In the meantime, lots of research is being done on what is best for our young horses so we will start to learn more about the effects of early exercise and training on the horse’s future, and hopefully have a better answer on the ideal age to start ridden work.
Of course, the same important preventative measures apply:
- Regular hoof trimming to ensure good foot balance
- Don’t overfeed or allow to become overweight but ensure your young horse has a good balanced diet including the correct levels of vitamins and minerals.
- You might consider adding a joint supplement in the feed; we will look at these in the next age group.
- Very importantly if there are any signs of a joint problem/swelling/lameness take immediate action to treat it. Call your veterinarian and discuss what anti-inflammatory measures you can take eg. icing, strict rest, supportive bandaging. Early treatment to reduce inflammation in the joint will help reduce the changes that can lead to OA.
The prime of life
age: Five to 15 years
For most sporthorses, this is the age when they will have their highest workload. But of course, it’s important to understand that there is usually a huge difference in the forces the joints of a 15-year-old have been exposed to compared to a five-year-old and correspondingly, our management will gradually change throughout these years.
What can we do to keep our horses’ joints as healthy as possible in this age group?
Keeping your horse in good physical condition, without lapses in fitness if possible, will give him the best chance.
The most important thing is to treat any early joint inflammation rapidly and as well as possible, with the aim of preventing it leading to arthritis. Check over your horse carefully each day, feeling over joints for any unusual swellings or filling.
Your veterinarian can show you where the joint pouches are, or you can find this information in a veterinary book. Be aware of any signs of even mild lameness. It is important to get a veterinary diagnosis and treatment plan depending on the cause of the lameness.
Although this age group can still get other joint problems, like an infected joint from a wound, these are much less common.
At this stage of life, prevention of OA comes down to prevention of joint trauma. Although it is impossible to avoid a sudden accident we can look after the joints in several ways.
Build up an exercise programme gradually to allow muscles, ligaments and tendons around the joints which stabilise the joint to strengthen and adapt to the exercise they are doing.
Always warm up and cool down – in the same way we are allowing the muscles, ligaments and tendons to function as well as possible if we gradually increase blood flow to these before starting more difficult work.
Keep the feet correctly trimmed and shod if required with good hoof balance – as already discussed this avoids unnecessary and/or uneven strain on joints. A horse might get away with poor hoof balance in the paddock, but now the joints are under pressure problems can start to show.
A good farrier is the key to a horse’s long-term soundness; you can take all the precautions in the world with workload and conditioning, but if your horse’s feet aren’t right, it doesn’t matter. Many studies have shown that every degree of hoof angle significantly affects joint loading, and repetitive strain on a joint from an imbalanced hoof is going to cause arthritis.
Now is the age when many owners will start to think about feed supplements or injections to prevent OA (and manage early OA). Joint supplements in feed are called nutraceuticals and include glucosamine, mussel extract, chondroitin and omega-3-fatty acids. Nutraceuticals are not regulated in the same way that medicines are, so the quality can vary between products. Although, at present, there is little scientific evidence as to their effectiveness, both owners and vets have reported an improvement when using some of these.
It is hard to assess whether a supplement will be preventing a problem, and in the case of early signs of OA it is often case of trial and error to see if a particular supplement will work for your horse. Talk to your veterinarian to see what they recommend.
Hyaluronic acid may be another option; this is a normal constituent of joint fluid and cartilage, which is thought to be changed or lacking in joints affected by OA. It can be supplemented by being injected directly into affected joints, given by injection into the vein or given as an oral supplement. At present there is no scientific data on the oral preparations.
Injections of polysufated glycosaminoglycans or similar (eg. Pentosan) are sometimes used. This has been reported to limit cartilage damage and have an anti-inflammatory effect in the joint as well as other positive effects. It is usually given as a course either by injection into the joint or into the muscle. The course of injections into the muscle can be useful when multiple joints are affected.
If a horse in this age group is diagnosed with OA it does not necessarily mean the end of their riding career. The arthritis will slowly progress, but treatment can be given to try and manage it, including joint injections or stem cell treatment, pain management and anti-inflammatories, and oral joint supplements. Weight management is important, and your vet may advise modifying your exercise programme, perhaps including swimming and physical therapy.
The management should be under the close supervision of your veterinarian to ensure the welfare of your horse.
The golden years
Age: 16 years onwards
Some horses in this age group will still be as fully active as ever, and others will be gradually slowing down. Obviously, a retired horse with the occasional stiff joint will be managed differently to one that is at the peak of their career.
A horse who is still doing a lot of ridden work will be managed as in the 5-15-year-old age group, above especially if it is a competition horse.
However, retired horses, perhaps already with signs of OA, should be managed so they are kept comfortable and their welfare is not compromised. The following points are important:
- Frequent light exercise (as long as they are not lame) is recommended as this increases both blood circulation and increases the movement of joint fluid (which lubricates the joints) around all areas of the joint.
- Regular hoof care – this is as important now as in the other stages of life.
- Good nutrition should be provided (and dental care so they can eat it) – with supplements if these work for this horse, and are affordable
- Weight management – keeping at an ideal bodyweight is important.
- Providing adequate shelter and areas with secure footing in winter is important.
- Testing for PPID (Cushing’s Disease) if there are suspicions that this may be present.
- Discuss with your veterinarians what medications are appropriate for your horse to keep them comfortable and pain-free. Some may need to be on treatment every day, others only every so often.
Summary
Osteoarthritis is, unfortunately, not just a disease of old horses. It is important to be aware of it, and what can cause it, throughout your horse’s life. The factors which contribute to the development of OA start right from the nutrition the foal’s dam receives. From then on, every step of the way throughout your horse’s life there is the opportunity to try and reduce the risk of OA.
Of course, no matter how careful we are, injuries still happen, and prompt appropriate treatment and anti-inflammatory care will give the joint the best chance of a full recovery. Early osteoarthritis can be managed and in lots of case can be managed very well. Gradually the OA will progress and then we should try and ensure our horse is comfortable in his or her retirement.
- This article was first published in the October 2018 issue of NZ Horse & Pony
