Which test typically involves checking the physiological response of a swine's immune system?

The HAD test, or Hemagglutination Inhibition Test, is utilized in veterinary medicine, particularly for evaluating the immune response of animals, including swine, to viral infections. This test measures the ability of antibodies present in the serum of the swine to prevent the agglutination of red blood cells by viruses. The presence and quantity of these antibodies can indicate the health status and immune response of the animal to specific pathogens, making it a valuable tool for assessing the physiological response of a swine's immune system.

In contrast, other tests listed serve different purposes. DIF tests focus on detecting specific diseases or immunological issues but do not typically assess the overall physiological immune response. A complete blood count primarily provides information on the cellular components of the blood, such as red blood cells, white blood cells, and platelets, rather than specific immune responses. Urinalysis is generally used to evaluate kidney function and detect urinary tract infections but does not assess the immune system directly. Therefore, the HAD test is most relevant for understanding the physiological response of a swine’s immune system.