What Causes Founder In Horses

Founder is a condition that affects the feet of a horse. It occurs when there is inflammation of the laminae, which are the tissues that connect the hoof and pedal bone. Because this inflammation is specific to the folds of tissue that are called the laminae, this condition is technically known as laminitis.

Laminitis may have many different causes. The extent of recovery the horse may experience depends upon how severe the founder is and when treatment first began. Some cases, such as those caused by a traumatic injury, may take several months to heal – if the healing process begins at all. 

What Are the Factors That Can Lead to Founder in Horses?

Several different factors may contribute to founder developing in an individual horse. Some horses are even predisposed to the condition. Horses that tend to be overweight or have suffered from previous bouts of laminitis are more likely to suffer a relapse or a repeat of founder in the future.

The most common reason for laminitis is a diet plan that doesn’t provide the right nutritional balance for the horse. A horse which consumes too many sugars and starch can overload their digestive system. This causes the carbohydrates to remain undigested, so they’re pushed toward the hindgut.

Once there, the carbohydrates are broken down by digestive bacteria, but that causes higher acidity levels in the digestive tract. This results in death for the bacteria. Toxins are released into the gut as the bacteria die and are passed into the bloodstream of the horse through the gut wall. The toxins create an internal response which disrupts blood flow to the extremities of the horse, which is why laminitis eventually develops.

These additional factors may also trigger founder in horses or contributed to severe symptoms.

1.    Stress. Horses that experience frequent or dramatic changes to their environment or companionship may flood themselves with enough stress hormones that laminitis can be triggered. Mares who lose their foals are particularly prone to founder.
2.    Infection. If a horse is already dealing with an infection, then it can spread to the foot and cause founder. Severe bacterial infections in or around the legs have the highest risks of transforming into laminitis. Severe colic attacks, prolonged diarrhea, and placenta retention may also provide increased risks to certain horses.
3.    Obesity. Some horses are large, but they are not overweight. It is the extra fat that a horse might pack on that can lead to founder. Horses need to receive an amount of exercise that is equal to their caloric intake. Having too many calories and not enough exercise places a strain on the connective tissues of the foot, which can then inflame and cause founder.
4.    Trauma. Horses that are worked for long periods or ridden on hard surfaces can create a concussion syndrome with their hoof that may lead to laminitis. The quality of the hoof may increase this risk as well. If the laminae experience irritation or trauma for prolonged periods, founder may not be far behind.

Another health issue that may cause some horses to develop laminitis is called Cushing’s disease. It may also be referred to as Pituitary Pars Intermedia Dysfunction, which is abbreviated to PPID. This condition can occur in any horse of any age, but it affects older horses, usually above the age of 15.

Common signs and symptoms of Cushing’s disease include changes to the coat, decreased movement, added fat deposits along the crest and tail head, and increased drinking, sweating, and urination. Laminitis is a common outcome for horses with a PPID diagnosis. 

Why Is Founder Such a Dangerous Disease?

Laminitis is such a dangerous disease of the foot because it stops the horse from begin active. It can also cause the foot to “sink,” which can lead to life-threatening consequences.

When founder develops, the tissues which form an attachment between the pedal bone and the hoof begin to fail. As that failure worsens, the weight of the horse begins to affect the actual structure of the foot. This is where the “sinking” process occurs. Without the tissue connection, the pedal bone can rotate and point towards the sole of the foot.

In a worst-case scenario, the pedal bone can even sink through the sole, making it impossible for the horse to be active unless the area is surgically repaired.

What Are the Symptoms of Founder in Horses?

When laminitis occurs in an acute form, the symptoms may occur suddenly and be instantly severe. A horse with founder will usually refuse to walk. In mild cases, there may be a reluctance to walk instead. Horses with founder will usually lie down and then be unwilling to stand back up.

You may also see the horse attempting to relieve the pressure on its foot by placing more weight on its unaffected feet. Because laminitis often causes pain within the frog, some horses may walk heel-to-toe on their affected hoof instead of toe-to-heel.

When walked on a hard surface, the horse will be visible lame. Many horses with laminitis will have an increased pulse in the foot as well.

For acute founder, some horses may also react in a way that suggests they have colic instead of a problem with their foot. That may include rolling on their back and an increase in aggressive behavior.

Chronic founder shows similar symptoms, but they tend to be milder and more progressive than immediate and sudden. Chronic symptoms of laminitis tend to come from relapses that occur after an acute case of the disease has been treated.

Besides the lameness symptoms, horses with chronic founder will also begin to develop growth rings in their hoof wall. They can look similar to hoof rings that are formed when the horse is stressed out frequently or has nutritional deficiencies. Laminitis rings show evidence of growth, much like the rings of a tree.

When chronic founder is present, the heel of the hoof will often grow faster than the toe. The white line in the hoof tends to widen as the disease progresses as well. 

How to Treat Laminitis in Horses

Before taking any action, it is essential that a veterinarian examine the horse if founder is suspected. A correct treatment plan must be developed from the symptoms and condition of the horse. This gives the horse the best possible chance to avoid lasting, and possibly permanent, damage to the feet.

A veterinarian will likely provide a prescription that will help with any pain the horse may be feeling as well.

If you suspect founder and you’re waiting for the veterinarian examination, then try to move the horse to a smaller enclosure. Bed down the area with sand or shavings so the hoof can sink into the material. This will take a lot of the pressure off the affected hoof while limiting the movement of the horse.

Horses that are suffering from founder may need to have their feed removed, but should have ready access to clean water at all times. Since most cases of founder are caused by dietary issues, the veterinarian may offer specific nutritional guidance to follow as part of the treatment plan that is developed.

Because of these sudden changes, many horses may feel an increased level of stress that can worsen their laminitis symptoms. This stress can be reduced by having a companion close by. Stall toys that do not require high levels of activity can be beneficial as well.

Do not ice the foot of the horse or spray it with cold water unless directed to do so by a veterinarian. Cold hosing provides relief, but it can also cause the tissues which support the pedal bone to shrink. A horse in extreme discomfort may feel better with ice or cold water, but the condition can worsen with repetitive treatment.

Horses suffering from founder should not be asked to stand.

How to Prevent Founder in Horses

A well-controlled diet and regular exercise are the best ways to prevent founder in most horses. A horse should be fed according to their size, workload, and type. Try to feel little, but feed often, for best results. Starving is never a good idea, even if the horse is overweight. Lack of food access can lead to hyperlipaemia.

Horses should visit their farrier on a regular schedule as well. When the hoof is in the best possible condition, the risks of laminitis are much lower. For high-risk horses, consider a food supplement that encourages hoof growth.

A horse should also be dewormed regularly or have egg counts performed on a regular basis. The schedule is individualized to the horse, so speak with a veterinarian about what the best options will be for this preventative measure.

Weight maintenance, pasture maintenance, and regular social activities can all help a horse feel more comfortable, reducing potential triggers that could lead to laminitis.

Founder is a painful condition. It can do more than be a debilitating nuisance. In severe cases, the life of the horse is at risk. Prevention is always the best option, but quick treatment is necessary when the signs and symptoms of laminitis are seen.