Managing a Laminitic
Saturday, 2 March 2013 | Admin
Laminitis affects so many horses and ponies, yet scientists still don't know exactly what triggers laminitis.
Some scientists believe that an upset in the microbial balance of the hind gut causes a rise in certain enzymes in the foot whilst others think it can be caused by vasoconstriction either by again distrubances in the hind gut microbial balance or earlier in the digestive trace due to a rise in insulin levels from the absorption of glucose.
Laminitis is a disease of the hoof which can vary from mild lameness to its worst case, the rotation and sinking of the pedal bone.
Risk factors for Laminitis
Excessive intake of soluble carbohydrates i.e. sugars and starches derived from either eating too much high-sugar/fructan grass (spring and autumn grass or after frost). Research suggests that frosty grass or closely grazed grass (think starvation paddocks) is high in fructans which cannot be digested by the horse, so pass straight through to the hindgut causing a reaction similar to an overload of starch.
Eating too much cereal feed or cereal based hard feeds especially molassed can also result in excessive overload of soluble carbohyrates, which in turn upsets the microbial content of the hind gut. Excessive soluble carbohydrates that reach the hind gut are digested by a minority of bacteria that are present there, which in turn then rapidly multiply producing lactic acid as they do so. When the hind gut becomes acidic its walls become permeable and one theory is that laminitis trigger factors leak into the bloodstream. When these trigger factors reach the foot, they cause changes that remain the subject of research. These changes precipitate laminitis. All these situations also result in temporarily increased insulin levels in the blood which may also trigger laminitis.
Other risk factors for laminitis include obesity because interal fat especially in the adominal region is hormonally active which again can cause changes in the foot that lead to laminitis. Obese horses also put more load onto their feet.
Hormonal factors can also predispose a horse to laminitis. For example, obese horses that are Insulin Resistant or suffering from Equine metabolic syndrome are more likely to develop laminitis. In addition to Insulin Resistant or EMS horses, horses with Cushing's disease are at increased risk of laminitis. Certain drugs which affect the hormone system e.g. corticosteroids also have the potential to trigger a laminitic affect.
Emotional Stress is another hormonal risk factor. Physical stresses to the feet such as repeated physical trauma caused endurance riding, driving or jumping on hard ground are another risk factor as is over-enthusiatics hoof trimming. A less obvious example of physical stress to the foot is when a horse has a severe lameness in one foot and puts excessive weight onto other limbs causing vasoconstriction which in turn can cause laminitis.
Finally toxins released by bacteria during certain illnesses e.g. colic, diarrhoea, retained placenta, liver or respiratory disease can predispose the horse to laminitis.
What to do if your horse shows signs of Laminitis
Any suspected cases of laminitis need the urgent attention of your vet. Call your vet immediately and always follow the advice of your vet.
Very mild cases of laminitis can often be nipped in the bud by changes in management, notably feeding.
If the attack is as a result of excessive intake of sugars and/or starch, nutrition should focus on two aspects.
Firstly reducing sugar and starch intake to a minimum in case an insulin response is involved and then re-estabishing the correct bacterial population and hence correct acidity in the hindgut. This is one in which fibre-digesting bacteria dominat and bacteria which digest sugars and starch are not allowed to proliferate excessively
The first action should therefore be to remove the cause of the laminitis e.g. bring pony in from grass or cut out any cereals out of the diet immediately. Stable the horse or pony on a very deep bed of shavings. Provide ample fresh water. Call the vet immediately and farrier when appropriate. Do not remove shoes unless on the advice of your vet.
Discuss what to feed with an experienced nutritionist. We would recommend calling the expert nutritionists at TopSpec on 01845 565 030 or email firstname.lastname@example.org. Whilst it is critical to minimise levels of sugar and starch in the diet it is also as important to provide ample fibre (low non-structural carbohydrate hay for example) and never starve a laminitic as this can be fatal.
As the exact trigger for laminitis is not known exactly, and can involved a variety of factors there isn't a 'one-size fits all' prevention method, however as a good number of laminitis attacks are triggered by excessive intake of sugar and starch it makes sense to manage the diet accordingly.
The following may help susceptible horses and ponies
Find the most suitable grazing possible. Unproductive grassland where ponies have to exercise a great deal to eat a moderate amount of average quality grass. Old meadow or parkland grazing is the next best and mixed grazing with sheep can keep the sward down. Pastures sown with 'improved' Italian Ryegrass is high in sugar and is best avoided. Limit access to lush pasture by either limiting turnout time, fencing off small areas or muzzling for limited periods.
As diet related laminitis invariably involves changes in the sensitive hindgut bacteria, never make rapid changes to the diet and this includes changing fields suddenly
Avoid fertilised and frozen pasture and try to turn out when sugar levels in grass are at their lowest, which is broadly speaking between midnight and dawn if practical. If the ambient temperature is below 5 degrees avoid turnout even if its not actually frozen
Avoid letting horses and ponies become obese. Build condition through an appropriate exercise programme and if extra calories are needed maximise the use of high fibre feeds which are formulated without the use of molasses or cereal grains. Again speak to an experienced nutritionist.
Avoid feeds high in sugar such as molassed coarse mixes and straw chops
Avoid feeds high in starch such as cereals or cereal-grain compound feeds
If hard feeds are needed, feed little and often - for example a 15hh horse should not receive more than 1.5kg dry weight hard feed at anyone time
Monitor the digital pulse daily and feet that remain hot over 48 hours may also be a warning. A loosening of droppings may also be a signal
Avoid unneccessary trauma to the feet e.g. hard, uneven, stony ground. Don't trot on roads and don't jump on hard ground. Avoid excessive hoof trimming.
Try to avoid stressful situations if possible i,e, unnecessary seperation from field companions
Finally see our list of Horse Feed approved by The Laminitis Trust.