Laminitis

"Laminitis results from the disruption (constant, intermittent or short-term) of blood flow to the sensitive and insensitive laminae. These laminae structures within the foot secure the coffin bone (the wedge-shaped bone within the foot) to the hoof wall. Inflammation often permanently weakens the laminae and interferes with the wall/bone bond. In severe cases, the bone and the hoof wall can separate. In these situations, the coffin bone may rotate within the foot, be displaced downward ("sink") and eventually penetrate the sole. Laminitis can affect one or all feet, but it is most often seen in the front feet concurrently.

The terms "laminitis" and "founder" are used interchangeably. However, founder usually refers to a chronic (long-term) condition associated with rotation of the coffin bone, whereas acute laminitis refers to symptoms associated with a sudden initial attack, including pain and inflammation of the laminae" (AAEP.org).

"Factors that seem to increase a horse's susceptibility to laminitis or increase the severity of the condition when it does occur include the following:

• Heavy breeds, such as draft horses
• Overweight body
• High nutritional plane (feeding large amounts of carbohydrate-rich meals)
• Ponies, Morgans, miniature horses and donkeys
• Unrestricted grain binges, such as when a horse breaks into the feed room (if this happens, do not wait until symptoms develop to call your veterinarian-- call immediately so corrective action can be taken before tissue damage progresses)
• Horses who have had previous episodes of laminitis
• Older horses with Cushing's disease" (AAEP.org).
  

"Signs of acute laminitis include the following:

• Lameness, especially when a horse is turning in circles; shifting lameness when standing.
• Heat in the feet.
• Increased digital pulse in the feet (most easily palpable over either sesamoid bone at the level of the fetlock).
• Pain in the toe region when pressure is applied with hoof testers.
• Reluctant or hesitant gait ("walking on eggshells").
• A "sawhorse stance," with the front feet stretched out in front to alleviate pressure on the toes and the hind feet positioned under them to support the weight that their front feet cannot.

Signs of chronic laminitis may include the following:

• Rings in hoof wall that become wider as they are followed from toe to heel.
• Bruised soles or "stone bruises."
• Widened white line, commonly called "seedy toe," with occurrence of seromas (blood pockets) and/or abscesses.
• Dropped soles or flat feet.
• Thick, "cresty" neck.
• Dished hooves, which are the result of unequal rates of hoof growth (the heels grow at a faster rate than the rest of the hoof, resulting in an "Aladdin-slipper" appearance)" (AAEP.org).

For more information on laminitis, you can read THIS article.