It’s the time of year again when laminitis rears its ugly head. There is much debate about what causes laminitis, why some horses and ponies are susceptible yet others are not, and how to manage and feed them to reduce the risk.
One thing is for sure – prevention is better than cure, because there is no ‘cure’, because it’s a painful disease (and can be fatal) and because once a horse or pony has suffered from it, they are more likely to have another bout.
Grass fructans, fatness, starch, sugar, insulin resistance, Cushings syndrome, poor trimming/shoeing, steroid tablets and injections, excessive roadwork, toxaemia… the list of factors linked to laminitis seems endless.
The fact there is so much debate and so many theories should cause us to realise that we don’t fully understand this disease yet, so although there are risk factors we should be aware of, there is no guarantee that you can avoid it.
Some of the theories that have been proposed are as follows:
• Grass fructans cause laminitis via hindgut disturbance since these plant carbs are not digested by gut enzymes like sugar and starch are
• Insulin resistance causes laminitis via high blood insulin levels and starvation of the hoof tissues of glucose
• Obesity causes laminitis via inflammatory compounds produced by fat cells
It’s likely to be a more complex condition than any of the current theories propose, and we do already know that it can be triggered in different ways. For example, a mare with a retained placenta is at high risk of laminitis from toxaemia – a quite different scenario to an overweight on spring grass who comes down with laminitis.
Then there is the question of equine metabolic syndrome (EMS). Can this cause laminitis?, you may ask. Actually, laminitis is part of the three factors that characterise EMS – along with obesity and insulin resistance – so EMS without laminitis is not possible. However, some slim horses – who therefore do not have EMS – get laminitis, so it’s not just as simple as obesity and insulin resistance.
Confused? Don’t worry. There are several steps you can take to reduce the risk of your horse or pony getting laminitis and these are absolutely vital if your horse or pony has suffered from laminitis in the past or is overweight.
- Restrict grass intake. We don’t understand how grass triggers laminitis and it may be partly due to the fructan content but also partly due to its effects on blood glucose dynamics and body insulin levels. Grass is very palatable and can be eaten much faster than preserved forage, so this might be a factor too. Don’t assume because your horse or pony is slim that they won’t get grass-induced laminitis
- Ensure a healthy bodyweight. Although obesity alone does not necessarily cause your horse or pony to get laminitis (many chronically fat horses and ponies never get laminitis), it certainly does increase the risk in some, so it is not worth the risk
- Exercise your horse or pony regularly, and ideally keep them fit. Exercise helps healthy weight maintenance and reduces insulin resistance
- Ensure your horse or pony’s hooves have regular attention from a trained professional. Foot balance is vital for good function, and a trained professional will be able to spot signs that all is not well in the early stages
- Feed a balanced diet. Add a multi-vitamin and mineral supplement if you feed less than the full recommended amount of a fortified compound feed. Limit sugar and starch intake for all but the hardest working horses. Feed plenty of fibre
Cushings syndrome is a condition that involves a hormone imbalance, and it increases the risk of laminitis, which cannot be controlled by the diet. Cushings syndrome is treatable with drugs and such treatment seems to be the only way to control the associated laminitis. If in any doubt, speak to your vet about testing your horse or pony for this condition. In the early stages, the hairiness, altered fat deposition, immune-suppression and increased thirst and urination are not necessarily present.
Finally, if you are at all concerned about laminitis, or your horse or pony shows even the slightest sign, please call your vet without delay. Laminitis is always an emergency and early treatment can mean the difference between your horse or pony surviving or not.