Canine Gastrointestinal Immunodeficiency Study Guide

Overview and Clinical Importance

Gastrointestinal immunodeficiency disorders in dogs encompass a range of primary (congenital) and secondary (acquired) conditions that impair the immune system's ability to protect the gastrointestinal tract and other body systems from pathogens. These disorders are clinically significant because they result in recurrent infections, chronic enteropathies, and failure to thrive, particularly in young animals.

The gastrointestinal tract houses the largest component of the immune system, known as gut-associated lymphoid tissue (GALT). This system provides both innate and adaptive immune responses through physical barriers, secretory IgA, and cellular immunity. When these mechanisms fail, dogs become susceptible to opportunistic infections and chronic inflammatory conditions.

Classification of Canine Immunodeficiency Disorders

Primary immunodeficiencies are congenital defects that affect formation or function of the immune system. These should be considered as differential diagnoses for repeated infections in young animals. Defects may lead to complete or partial loss of immunity.