Laminitis is defined as inflammation of the laminae of the hoof.

Laminitis is a vascular disease. Ateriovenous shunts that act to equalize/distribute pressure within the hoof during weight bearing become paralyzed and dramatically increase the blood pressure and create vascular damage within the hoof.

Pathogenesis:
Excess grain ingestion -> lactic acidosis -> histamine release -> thrombosis of blood vessels in the foot. Epidermal changes also occurs. In laminitis the proportions of sulfur-containing amino acids in keratin of the horn are changed; there is a reduction in the proportion of cystine and methionine leading to a softer, waxy horn of the foot. Hemorrhage occurs with edema, venous stasis and congestion of the capillaries. Treatment includes antihistamines early, non-steroidals, anti-inflammatory drugs, and treatment of underlying diseases (mastitis, metritis, etc). Methionine supplements may be beneficial.

Insults are cumulative; can usually recover from a single episode. Laminitis in cattle is primarily a disease of the sole, not side wall as is seen in horses. Results from disturbances of the microcirculation of the corium produces inflammation and degeneration of the dermal-epithelial junction.

Laminitis is seen as either Acute Laminitis or Chronic Laminitis.