Although well adapted for running, modern horses are susceptible to a foot condition called laminitis, a deterioration of connective tissues within the hoof (See following figure). Strong fibrous tissues called laminae occupy the space between the bone and hoof. The laminae support the terminal bone (3^rdphalanx) and connect it to the hoof wall. In horses suffering from laminitis, these connective tissues become swollen and then detached, allowing the bones to twist, penetrate the hoof, or sink within the hoof. If not properly treated, the animal will become lame. In some cases the lameness can be remedied, but sometimes the lameness is so debilitating that the animal needs to be euthanized.

(a)

Normal foot anatomy.

Foot of horse with laminitis.

Although the cause of laminitis is not known, many predisposing factors have been correlated with the onset of laminitis. One of these factors is overfeeding with lush spring grasses or other sources of high carbohydrates. One hypothesis is that the excess carbohydrates lead to toxins in the blood that irritate the sensitive laminae.

What are some differences between the normal foot and the foot with laminitis? Consider where the weight of the horse is placed.

Transcribed Image Text:

1st phalanx 2nd phalanx Hoof wall Laminae 3rd phalanx Sole Separated laminae