Final answer:
The presence of bilirubin in the urine is generally considered normal in equines (horses), whereas it is usually abnormal and may indicate liver disease or hemolytic disorders in canines and felines.
Step-by-step explanation:
The presence of bilirubin in the urine is typically abnormal for most animals, as it is indicative of a liver not functioning properly, which fails to conjugate and excrete bilirubin produced in normal amounts. This condition can lead to the occurrence of jaundice or icterus, where excess bilirubin, a breakdown product of hemoglobin from red blood cells, builds up in the body. In animals such as canines and felines, the presence of bilirubin in the urine may point towards liver disease or hemolytic disorders. However, it is generally considered normal in equines (horses), as they often have a small amount of bilirubin in their urine without it being indicative of liver disease. Swine typically do not have bilirubin in their urine when healthy.