How do I prevent Founder in my horse?

Laminitis, or "founder" as it is more commonly known, is a distressing and potentially crippling disease which affects the sensitive support of "laminar" tissues within the hooves of horses. Although the disease most commonly affects overweight, "cresty" ponies grazing on lush pastures during the spring months, all horses are at risk of developing laminitis and the condition has affected many champion performance horses at the peak of their career.

There are a number of predisposing causes of laminitis, but studies have shown that up to 80% of cases are caused by complications resulting from excess carbohydrate intake, leading to hindgut carbohydrate overload.

How does carbohydrate overload occur?

Carbohydrates, particularly soluble starches and sugars are feed components found in concentrated amounts in cereal grains, lush grasses and legumes, such as clover and luceme. When these feeds are eaten in large quantities they are unable to be digested in the small bowel in the normal 8-10 hour period. Exess amounts of undigested carbohydrates are passed into the large bowel or hindgut. In the normal diet, certain bacteria in the hindgut ferment and break down residual carbohydrates in the food mass. Where excess starches and sugars are "dumped" into the hindgut, these bacteria rapidly multiply to ferment the carbohydrates, and in doing so, produce large quantities of d-lactic acid. The high hindgut lactic acid level not only supresses other bacterial action on fibre and protein, but they die in large numbers, releasing toxens that are absorbed into the blood.

The toxins have a direct affect on the basement and bonding membrane of the laminae, and are thought to trigger changes in blood flow to the feet. This results in the devitalisation of the laminae bonds and loss of structural support of the pedal bone within the hoof. When bearing heavy shoulders and cresty neck, or exercising, the devitalised laminae tear, resulting in loss of pedal bone support, allowing it to rotate downward as occurs in "founder".

Which horses are most at risk of carbohydrate-induced laminitis?

Any horse that is on a high grain diet, lush pasture, or a hungry or greedy eater is prone to overloading carbohydrates into the hindgut.

  • Performance horses such as gallopers, pacers, eventers, etc. receiving very high levels of grain to provide energy for training and competition.
  • Young horses being prepared for yearling sales often receive high grain rations and inadequate amounts of exercise.
  • Hacks and ponies in show condition are often overweight and receive grain levels in excess of their exercise requirements.
  • Horses and ponies grazing on lush spring or autumn pasture, particularly if they are overweight or cresty, and receive insufficient or infrequent exercise.
  • Horses which undergo sudden changes in their diet such as when horses are brought in from the paddock and put straight onto hard feed, or a horse unaccustomed to grain.
  • A greedy eater or feed bolter that gorges on hard food containing grains, or a hungry pony turned out on spring pasture.

Intake of rapidly growing spring pasture with a high soluble sugar content, often about 2-3 weeks after break of the season rains, or within 7-10 days of slashing or topping a fast growing spring pasture, can increase the risk of carbohydrate overload and laminitis.

  • Horses with a previous history of laminitis from any cause appear to be more sensitive to feed-induced attacks of founder.

How can I prevent Laminitis and Founder?

There are a number of feeding and management hints that can be adopted to reduce and prevent the risk of laminitis and founder.

The most effective way is to provide a daily dose of the product Founderguard. Founderguard prevents feed related laminitis by controlling the bacteria that multiply rapidly to ferment excess carbohydrates dumped into the hindgut. Founderguard prevents a build-up of lactic acid, and the resulting release of endotoxins. Founderguard has proven very successful in reducing the risk of laminitis in horses on high grain diets, and in horses which are known to be sensitive to grain. Studies in ponies and horses grazing lush spring pastures suggest that Founderguard suppresses lactic acid producing bacteria in a similar way.

In order for Founderguard to work it must be fed daily for at least 3 days prior to an increase in the carbohydrate content of the diet. It should be started at half the recommended daily dose initially, and increased in a step-wise manner to the full dose with a 3-4 day period. It must then be continued daily throughout the high risk period.

Founderguard is economical - costing about 30 cents per day for ponies, and up to 50-60 cents daily for a large horse.

The use of Founderguard as the primary preventative supplement should also be complimented by good feeding management.

Some hints include

  1. Feed only to the level of exercise, cut grain back on rest days, which will also help to avoid "tying-up" as well.
  2. In a greedy eater, dilute grain 50:50 with chaff to slow intake, and if necessary, place a piece of weldmesh (50mm x 75mm mesh) through the top of the feed bin to fit snugly into the feeder - it slows them down so that they cannot overload their small bowels and dump more undigested carbohydrates into their hindgut which can encourage uncontrolled fermentation and lactic acid carbohydrates build-up.
  3. In most cases, it takes about 10-14 days for improved pasture to increase its soluble sugar content after a good opening rain, or 5-7 days after a week of wet warm spring weather.
    Grass that has been grazed off, topped or slashed and regrows quickly under these conditions, can be a problem within 5-7 days. Preventative management and treatment should be started within 5 days after rain where ideal growing conditions exist and maintained daily whilst the grass is lush and plentiful, particularly regrowth after topping or resting a pasture from grazing.
    Turn susceptible ponies only out for short periods of 1-2hours during the day time - never leave them out overnight on lush pasture - a common mistake! At night, the daylight photosynthesis is converted to sugar storage, and combined with daytime wilting and moisture loss, the sugar content increases. At night horses and ponies often graze for longer uninterrupted periods and risk overloading the gut with lots of carbohydrates - especially if it is a cool night and they are hungry.
  4. If you are turning a susceptible horse or pony out - give it some hay or chaff - dampened with molasses (no worries with small amounts of molasses as they absorbed readily from the small bowel and will not overload sugars) to fill it up before it gleefully rushes into the pasture to "pig out" on lush grass. The animal will already be fairly full, and dry hay and chaff slows the rate of bowel movement and reduces the risk of dumping excess soluble sugars into the hindgut.
  5. Ensure that you do not allow horses to become too fat and cresty - grey ponies appear more susceptible - restrict their intake to a little feed often - but do not completely withdraw food and starve pony breeds as there is a risk of inducing a type of fatty liver disease (hyperlipaemia) and death in 7-10 days.
  6. Exercise susceptible horses regularly to maintain their energy-exercise-appetite equilibrium, and hopefully avoid excess weight gain and risk of laminitis. If they develop "ouchy feet" due to low grade laminitis - do not exercise them - call your vet for advice.
    Remember, thin horses can still have founder if stressed, or suffering from severe disease, infection or diarrhoea.
  7. Keep the toes on the front hooves trimmed regularly every 4 weeks - this helps reduce the risk of mechanical tearing of weakened laminae by the lever action of long toes and low heels in susceptible horses.