Clinical immunology and immunopathology of the canine and feline intestine.

The mucosal immune system is at the forefront of defense against invading pathogens, but at the same time, it must maintain tolerance toward commensals and food antigens in the intestinal lumen. The interplay between the innate immune response and commensal microorganisms is essential to maintaining this balance. Great progress has been made in identifying some of the genetic predispositions underlying inflammatory bowel disease in certain breeds, such as the German shepherd dog. Several immunologic markers are discussed with respect to their clinical usefulness in the diagnosis and management of inflammatory bowel disease.