Bovine Leukocyte Adhesion Deficiency (BLAD)
Bovine leukocyte adhesion deficiency (BLAD) in Holstein cattle is an autosomal recessive congenital disease characterized by recurrent bacterial infections, delayed wound healing and stunted growth, and is also associated with persistent marked neutrophilia. These clinical findings were associated with impaired neutrophil functions such as markedly decreased adherence, chemotaxis, and phagocytosis. Cattle affected with BLAD have severe ulcers on oral mucous membranes, severe periodontitis, loss of teeth, chronic pneumonia and recurrent or chronic diarrhea. Affected cattle die at an early age due to infectious complications. The frequency of BLAD carriers in Holstein populations varies depending on the country, year and policy of diary cattle improvement.