When I was training as a vet, a 20 year old horse was considered really quite old. Now, however, I regularly find myself working with healthy horses in their late twenties and thirties – even a few that go on into their forties!

That said, horses don’t age uniformly – one may be sprightly and fit at 30, while her paddock mate is really feeling his age at 20, so there’s a lot of variation. The challenge is maintaining them at the best quality of life for as long as possible.

To do so, we need to consider three things:

• Work and exercise
• Preventative health (worming, dental care etc)
• Disease management and medication

I’ll deal with these in sequence, although really they are of course all interconnected.

Work and Exercise

PerryI’d like to introduce Perry, a horse I’ve known for many, many years. Born in 1986, by 2002 Perry was a successful Eventer, competing on the Affiliated circuit, and usually well up in the places. However, by then he was starting to slow up a bit, and his then-owner decided it was time to reduce his workload. He was struggling in particular with the dressage and show jumping, so they sold him on to a friend of mine as a Pony Club horse for Tetrathlon. All he had to do was carry his (fairly novice) rider round a cross country course – the phase he enjoyed the most anyway. Relieved of the need to work in an outline, or in collection, he flourished at Tetrathlon, going on to compete at the National Championships.
Of course, in time, his low-grade arthritis (which I’ll talk about more later) meant that he was struggling with the cross country requirements, and he moved into a semi-retirement as a hack. He’d seen it all, done it all, and was as close to 100% in traffic, tractors and low flying aircraft as any horse could be.
For most horses, as long as they can work, they want to – generally (and there are always exceptions!), it isn’t in a horse’s best interests to take him out of work one day and retire him to a field. A gradual wind-down over several years is kinder, and helps to keep him interested and alert.
So, by changing career, Perry had an extra five years of competition, and then many more years of useful work – simply because his various owners were wise enough not to over face him, but to play to his strengths.

Preventative Health

I’ve talked before about the importance of regular dental work – in the older horse, it is doubly important. As the horse ages, his teeth undergo a number of changes. Although it appears that teeth grow constantly, that is in fact an illusion – the adult teeth are pretty much a fixed length, but most of the tooth is hidden away within the gums (the reserve crown). As the tooth is worn down by chewing, more of this reserve is extruded (which is, by the way, the basis of ageing horses by dentition). However, sooner or later, this reserve is expended, and the teeth “cup out”, becoming small, loosely held, concave structures, of limited use for chewing. Good, regular dental care can help delay the onset, and can help the horse to manage as the teeth cup out. Remember, as long as there are a few pairs of teeth in occlusion (i.e. Facing each other), the horse can still chew, he’ll just be very slow about it! In my experience, teeth generally start to cup out about 30-35 years of age, but it depends on their dental history – more use and wear and tear means the teeth are ground down faster.
Worming is also inceasingly important in the older horse, simply because although they may have higher immunity to worms (this is still debated, but does seem likely), they also have less reserves to cope if they have a heavy infestation. The spring is a particularly risky time, as sometimes large numbers of small redworms can emerge all at once, causing massive gut wall damage. It is important to make sure that at some point over the winter, you use a wormer that is active against hibernating (hypobiotic) worm larvae – currently, the only wormers on the market that have this activity are a full 5 day course of Panacur, and (reportedly) Equest.

Foot care is always important, as older horses can suffer some terrible hoof capsule problems if left untreated.

I always recommend that people keep up vaccinating their horses, even if they’re not competing or going out. Equine influenza probably isn’t essential in a stay-at-home horse or pony (although they can still contract it if they’re in contact with a younger friend who does go out and do), but Tetanus vaccination is essential. Just because a horse is old doesn’t mean you can stop vaccinating, because tetanus kills horses of any age just as easily. It’s also a really useful opportunity to have a general “MOT” and get your vet to check the horse over thoroughly, to detect and problems before they become too serious.

Disease Management

Although many horses lead a long and healthy life, the probability is that as they enter old age, they will suffer from one or more “chronic diseases”. These are generally low-level conditions, and in the older horse are usually manageable rather than curable. Probably the most common are arthritis and Cushing’s disease, but malabsorbtion diseases and some tumours aren’t that uncommon either.

The key factor is managing the disease in such a way that the horse doesn’t suffer from the symptoms, and is able to keep up as much work as possible, for as long as possible.

Arthritis is perhaps the commonest condition of older horses, and those that aren’t so old. In most cases, it is due to simple wear and tear on the joint surfaces. The harder a horse has worked, the more rapid the onset of arthritic changes. It’s often the case that, initially, a horse will have trouble working in an outline, and perhaps with show jumps, but hacking and cross country, with it’s more open jumping style, is less of a problem. This of course was exactly the case with Perry. Managing arthritis is a lot more than just monitoring exercise, however – nowadays, we no longer need to just accept “a bit of stiffness” in the older horse. It’s often best to use several different strategies. I generally recommend a combination of joint supplementation (feed supplements such as Cosequin and Newmarket Joint Supplement are the most popular, while injectables like Adequan are more expensive but possibly more effective) with analgesics (bute and/or Danilon, usually) as required. Although painkillers like bute don’t address the underlying disease, they reduce the inflammation and associated pain. Although there can be side effects, it really isn’t fair to put a horse through the pain and discomfort of arthritis without some pain relief; if side effects are a particular concern, Danilon has a much lower risk, although it seems to be a little less effective. Its usually best to start out using bute only as required, and then build up the dose as necessary. Perry, for example, started using bute about 10 years ago, but just a sachet or so immediately after a competition. As he’s got older, he uses more, and at the moment he’s on an average of 4-5 sachets a week – enough to keep him comfortable (and galloping round his paddock like a yearling!).

Cushing’s disease (hyperadrenocorticism) is most common in older horses, and is caused by a micro-tumour in the pituitary gland. This results in an excess of circulating cortisol (a stress hormone), that causes the characteristic symptoms of abnormal fat pads (typically over the eyes and as saddle-packs), excessive drinking and urination, and increasing susceptibility to minor infections and laminitis. Ironically, the “classic” shaggy coat of the Cushingoid horse isn’t entirely due to cortisol – the presence of a tumour in the pituitary causes a malfunction in the part of the brain that controls body temperature, causing retention of a winter coat for longer. Cushing’s isn’t curable in horses, but symptoms can be partially controlled by management (regular clipping, diet and exercise control and remedial shoeing), or largely eliminated with some medications – Cyproheptadine (Periactin) may be of some use; however, Pergolide (Prascend) is highly effective, and is licensed for the treatment of Cushing’s.

Gut problems of one sort or another are also more common in older horses – these may be malabsorbtion issues, caused by thickening of the gut wall, or an increased susceptibility to colic. This may be due to a diffuse Lymphoma (a cancer of the white blood cells) which is the commonest tumour of older horses. In these cases, the key is to feed a highly digestible, high feed value ration, possibly with a probiotic to enhance digestion.

Tooth loss is also a problem in the older horse – as I discussed earlier, eventually the teeth “cup out”, at which point there’s little more that can be done, dentally. The next phase is that the tooth falls out, leaving naked gums. I remember once doing a regular tooth rasping on a 38 year old mare – I put a hand in to have a feel around, and four teeth fell out in my palm… (she actually did better once the teeth were out than she had in months!). An edentulous (toothless) horse needs a soft, ultra-high fibre diet; typically a mash made from fibre pellets or pencils. Horses can live healthily for quite some time on such a diet – however, once your horse has reached this stage, it is probably time to consider how long you can fairly keep him going.

If you can stay on top of all these points, you have every chance of keeping your older horse going for a long, healthy life – as Perry has had, and indeed continues to have.

If you are worried about any symptoms your horse or pony is showing, please talk to your vet or check how urgent the problem may be by using our Interactive Equine Symptom Guide written by expert equine vets.