Etiology and Pathogenesis
- Acute laminitis parallels the acute "founder" seen in horses. Usually a sequalae to serious digestive disturbance. The role of endotoxin (gram neg. bacteria) is assumed. Histamine may be involved.
- Highly fermentable carbohydrates etc -> rumen acidosis.
- Mostly seen in younger animals. Beef -> feedlots when first put on feed. First calf dairy heifers -> diet changes from low density to high grain diets.
Clinical signs include stiffness, pain, reluctance to walk, and difficulty in rising. Affected animals spend alot of time lying down and when they do stand, their backs are arched with their feet placed underneath them more than usual. They may stand with crossed front legs. Swelling and tenderness occur above the coronet and over the heel bulbs. There is venous distension in the lower legs and a digital pulse may be palpable. The horn of the sole might become soft, yellow, and waxy, and hemorrhage and bruising often occurs under the sole.
- Animal will often lie down as much as possible, often in unusual places
- walk on their carpus, "praying position"
- increased digital pulses
- soles sore to hoof testers
- do not see heat characteristic of equine acute laminitis
- sole hemorrhage will develop, often goes on to abscess
- "hardship grooves" or alterations in the sidewall of the hoof will be apparent later
- caused by sudden stoppages of normal hoof growth
Symptomatic and supportive.