If you’ve owned horses for any length of time, then you’ve likely encountered a hoof problem or two at some point. Whether it’s wall cracks, an abscess, or something more serious like laminitis or white line disease in horses, unfortunately, hoof issues can be common.
For this final part of our hoof series in which we’ll share information from an interview with Dr. Scott Fleming, equine podiatrist at Rood and Riddle Equine Hospital, we’ll focus on some of the more debilitating horse hoof diseases.
Laminitis in horses
Laminitis is perhaps the most dreaded hoof disease of all, and not without good reason. Dr. Fleming describes the condition as, “inflammation of the lamina, the interconnection between the hoof wall and the suspension, or the apparatus that holds the coffin bone in place.”
Laminitis is often triggered by an overload of carbohydrates from feed or grasses, and it is especially common in spring and fall when the non-structural carbohydrate (NSC) level in grasses is higher than normal. However, laminitis can also be caused by mechanical issues in the foot. For example, if a horse has had a long-lasting abscess in one foot, they may load too much body weight on the opposite foot and develop laminitis as a result.
Some horses are more prone to developing laminitis due to underlying conditions such as insulin resistance, which Fleming compares to diabetes in humans. Another condition which predisposes a horse to laminitis is pituitary pars intermedia disorder (PPID), also known as Cushing’s disease.
“That's where the body is making too much internal steroid, and that's bad for the feet,” explains Fleming.
No matter the cause, laminitis should be taken seriously and help should be sought as soon as symptoms appear, as this condition can cause debilitating pain for many horses.
Clinical signs of laminitis in horses include:
- Heat in the hoof;
- Increased digital pulse;
- Pain in the toe region when pressure is applied with hoof testers; and
- A sawhorse or camped out stance.
When treating laminitic horses, Fleming says that he and his team focus on minimizing the leverage of the hoof.
“We're trying to reduce tension in the soft tissue that connects to the coffin bone,” says Fleming. “Oftentimes we add a wedge to try to reduce the strain, and when we wedge them, it brings the weight-bearing, the center of gravity, a little further back in the foot, hopefully, away from those more compromised tissues in the very front of the foot, where you see the rotation.”
However, treatment isn’t always effective in some cases, and in those instances, the best decision is euthanisia.
“Laminitis is certainly one of the most frustrating things that I deal with as a practitioner,” says Fleming. “Despite all the advances that we've made in therapies, we are still unable to help some horses.”
Fungal and bacterial infections of the hoof
Two common fungal and bacterial infections of the hoof include white line disease (WLD) and thrush.
WLD is characterized by an infection that affects the area just in front of the epidermal laminae, the sensitive tissues that attach the hoof wall and help suspend the coffin bone within the hoof capsule. It involves hoof wall separation where opportunistic bacteria and/or fungi find their way into the hoof. Eventually the fungi take over.
The causes behind WLD aren’t completely understood, but researchers believe that any hoof distortion or change in the horse’s weight-bearing (loading) pattern can put a horse at risk. Examples include long toe/low heel syndrome, club foot, or simply overgrown hooves.
WLD can be frustrating because it isn’t always easy to detect and it’s not always easy to treat. A horse won’t likely show lameness unless the disease has progressed to a severe degree, but an experienced farrier can likely spot signs of the disease earlier on.
WLD treatment often involves removing diseased hoof wall and using hoof soaks targeted at killing off any remaining fungi. Keeping the hoof out of mud and wet ground is important as well. WLD can affect one, two or all four feet.
Thrush in horses’ feet can also become severe in some instances and can be an overlooked source of lameness. Caused by an anaerobic bacterial infection (Fusobacterium necrophorum), thrush in horses typically develops in the frog or central sulcus near the back of the foot.
In some cases, thrush can cause enough pain to affect hoof loading, leading a horse to bear more weight at the front, rather than the back, of the hoof.
Symptoms of thrush may include:
- Repulsive odor;
- Watery or oily discharge (often black in color);
- Tenderness in the frog;
- Crevices or deep pockets extending to the heel bulbs; and
- Loss of frog shape and integrity.
Since thrush is caused by yeast, fungus, and/or bacteria that invades the hoof, treatments should aim to kill off disease causing agents while preserving live tissue. Your farrier may remove diseased parts of the frog, but this alone, may not solve the problem.
The common thread is diet
Interestingly enough, one thing that many hoof diseases have in common is diet. Avoiding high amounts of carbohydrates, whether it’s in the form of grain or high-NSC grasses, is important for all horses, especially those at risk for developing laminitis. Though environment can certainly play a role, high-NSC diets and mineral imbalances have been linked with thrush and white line disease as well.
By ensuring that your horse is eating a species-appropriate diet, including the recommended amounts of protein, vitamins, and minerals, and also possibly adding a hoof supplement with added biotin and methionine, you can reduce your horse’s risk of developing certain hoof diseases.
“I've seen horses benefit from supplementation,” says Fleming. “It could be regionally dependent as well, where you have plenty of nutrients in forages in one environment and a deficiency in a different part of the country.”
Supplementing with probiotics can give your horse added protection by improving absorption of those nutrients. Gut health is vital to the horse’s overall health, including the hooves.
Dr. Fleming also recommends keeping the horse out of an overly wet environment which can invite bacteria and fungi into the hoof and keeping a routine farrier schedule to avoid hoof overgrowth which can lead to mechanical problems and the development of disease.