What diagnostic test is commonly performed to check for the presence of parasites in animals?

Fecal examinations are commonly performed to check for the presence of parasites in animals because many internal parasites, such as worms and protozoa, are shed in the feces. This test involves analyzing a sample of the animal's stool under a microscope to identify eggs, larvae, or adult parasites. The presence of these elements in the feces provides direct evidence of a parasitic infection.

In contrast, blood tests primarily assess the overall health of the animal, detect certain diseases, or identify specific pathogens, but they are not the go-to method for diagnosing intestinal parasites. Urinalysis is used to evaluate the urinary system and may help detect issues related to the kidneys or bladder but does not provide information on gastrointestinal parasites. X-rays are imaging studies that allow visualization of internal structures but, similar to urinalysis, do not directly identify parasites. Thus, the use of fecal examinations is the most efficient and effective method for diagnosing parasitic infections in animals.