The immune system is one term but is composed of a host of things including specialized cells, proteins, tissues, and organs. All of these together fight against a variety of infections. Antibodies are proteins which bind to foreign substances, known as antigens, and destroy them. When the immune system malfunctions and treats its own RBCs as antigens and starts destroying them, it results in the hemolysis of red blood cells. This in turn results in the release of hemoglobin causing jaundice. Anemia results when the production rate of RBCs is not enough to replace the ones being destroyed.
Commonly affected breeds include Irish setters, poodles, English springers, cocker spaniels, collies, and Doberman pinschers. Typically this disease is seen in dogs of age 1-13 years. Female dogs are found to be at higher risk than males.