To find out the cause of the animal's death, the scientists and researchers must look through the microscope at slides of the animals red and white blood cells. Serology, analyzing the serum of the animal's blood allows them to see if they had a virus infect them. They also look for parasites, which is referred to as parasitology. Urinalysis checks for urinary tract infection. Toxicology is very necessary for the California condors to check for lead poisoning.
Scientists also check for blood alcohol levels, carbon monoxide and zinc poisoning.
The list goes on and on for methods and tests that the scientists use to figure out what caused an animal to die. One major reason is, the pathologists can find out the cause of death and prevent the other animals that may have come in contact with the deceased animal or shared its enclosure, from getting sick. Every week water samples are taken from the exhibits with pools and given to the pathology lab to be checked for parasites. A special machine in the lab is used to separate and count red and white blood cells of a certain animal to make sure it is doing okay. In a few cases, analysis and tests of these animals is to make sure they are healthy enough to put back into the wild.