Let's start with Laminitis!

We have been seeing a lot of foundering horses recently, so I thought the best topic for us to start our blog on is Laminitis! There is a lot to talk about with this disease, so we will post more information each day!

What is Laminitis or “Founder”?

Laminitis by definition is inflammation of the laminae in the hoof. The laminae are microscopic finger-shaped projections (see picture) that connect the hoof wall and the coffin bone, and that keep the coffin bone suspended inside of the hoof. As you can imagine, there is a LOT of weight being placed on the coffin bone, so when these connections become inflamed and begin to separate, the coffin bone can begin to either sink or rotate.

Microscopic view of the laminae

Another important anatomic factor are the flexor tendons. These tendons run down the back of the leg and connect to the back side of the coffin bone and exert quite a bit of tension. When the coffin bone has more give (during a laminitis episode), the tendons are what can cause the rotation of the bone.

What causes laminitis?

There are many different causes of laminitis. It can be caused by overweighting of the foot (think: horses that have an injury on one leg and are constantly bearing all of their weight on the “good” leg) and other systemic illnesses such as diarrhea, colic, and pneumonia. However, the most common cause we see is metabolic laminitis. This version is caused by hormonal changes associated with obesity and feed. A good disease to compare this to is diabetes in overweight people (although keep in mind, it is not the same condition). People with diabetes have problems controlling their blood sugar levels, as do horses that are overweight. This problem is called “insulin resistance”, and is without a doubt present to some degree in all overweight horses. A more severe disease in horses that is closely related to insulin resistance is called Cushing’s disease. The steps by which insulin resistance cause laminitis are very complicated, and unfortunately, a lot is still unknown. A great deal of research is focused on clarifying this process so that laminitis can be better controlled, and hopefully someday prevented.

....That's it for today. Tomorrow's post will further discuss Insulin Resistance and Body Condition Scoring!