Why do horses and ponies suffer from laminitis if they are on good pasture?
Horses and overweight ponies with a chunky body type are sometimes vulnerable to fructans in spring grass and may develop grass laminitis (founder).
Some locking up is required, the weight must absolutely be reduced and feeding oligosaccharides may reduce the dangers of founder. Animals with laminitis should be presented to a veterinarian for diagnosis and treatment.
You need to consider how laminitis can result from dietary intake. Vetpro's Tina Thorowgood says that starches and sugars (carbohydrates) are the problem in this disease. Grass contains starches and sugars and grain is full of starches. Normally these carbs are digested in the small intestine assisted by enzymes which exist in that part of the horse's digestive tract. If all carbs are digested there then there is not a problem. But if overloaded, the undigested carbs can move through to the hindgut (called the caecum) and that’s where the problem lies.
The hindgut does not contain the right kind of enzymes to aid digestion so the horse produces lactic acid to compensate. Unfortunately, this lactic acid kills off good bacteria and, as they die, they give off a toxin. This toxin passes into the bloodstream and moves through the fine laminae of the feet causing the problem called laminitis.
This toxin is not the same one as in mouldy feeds or endophyte grasses that is a fusarium toxin and some binders can be useful to remove them. However, they are not effective in dealing with the laminitis toxin. That particular toxing requires mannan oligosaccharides (MOS) to help clear it. Additionally, extra intake of starch-digesting enzymes will help to digest the excess starch in the small intestine, thus reducing any undigested excess passing on to the hindgut.
It is common to restrict grass intake and only feed a little fat and some fibre to animals prone to laminitis. However, this creates an unbalanced diet which results in light condition and a hungry horse. Tina believes that its better to help the horse or pony to improve its digestion and be able to take in some grass and keep good condition.
So what can be done to help minimise the risk of laminitis?
Firstly feed a supplement like Vetpro Digest-Rite will provide the enzymes needed to improve initial digestion and also the MOS to clear the toxins. In addition always wash any hay as washing dissolves a lot of the sugars.
Avoid grazing early in the morning as the sun comes up during spring and autumn months. Grass produces sugar and starch overnight but only uses the sugar to grow when the temperature warms up, so cool mornings mean a delay in that usage. That's when the sugar content is at its highest. As the day gets warmer the sugar level drops as the grass consumes it in the growing process.
Tina says that its best to pen or stable your horse at night, with washed hay, and to go out to pasture when the sun is up. Avoid feeding grain but add Vetpro Digest-Rite into your horse's diet. Vetpro get many reports of successful results using this approach and there's a lot of scientific evidence which supports the use of enzymes and MOS.
Be aware that there other causes of laminitis and you need to discuss symptoms and your observations with your veterinarian to be sure that you have identified the cases. Vetpro have details of the scientific tests on the use of enzymes and MOS available on their Vetpro Digest-Rite page
Read more about carbohydrates, digestion and behaviours responses in Vetpro Articles