The Science of Pathology

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Zoo InternQuest is a seven-week career exploration program for San Diego County high school juniors and seniors. Students have the unique opportunity to meet professionals working for the San Diego Zoo, Safari Park, and Institute for Conservation Research, learn about their jobs, and then blog about their experience online. Follow their adventures here on the Zoo’s website!

Camille_W5_picHave you ever wondered what happens to the animals at the Zoo after they pass away? Well, last week the interns had a firsthand look through the necropsy and histology buildings at the San Diego Zoo’s hospital. Our guide through the necropsy and histology buildings was Megan McCarthy. Dr. McCarthy is a DVM Pathology Resident at the San Diego Zoo.

So what exactly is pathology? Before our trip into the necropsy and histology, Dr. McCarthy gave the interns a presentation all about veterinary pathology, and the roles that those in the field play at the Zoo. Pathology is, essentially, the study of viruses and diseases. The pathologists at the Zoo perform necropsies or “animal autopsies” to identify the cause of death in collection and non-collection animals that die on the Zoo’s premises. Pathologists study and examine the sample tissues they extract during the necropsy to identify any traces of disease that had not been seen during the actual autopsy itself. Even though most people do not know about veterinary pathology, the work they do is extremely important to keeping the collection animals at the Zoo healthy and avoid any possible outbreak of disease.

For most Zoo visitors, the process that animals go through after they die is not something on their mind. However, the process is also very necessary to ensure the health of all the animals residing at the Zoo. After an animal passes, they are first sent to the necropsy building. It is here that the animal is delicately examined to identify any signs of disease that can be seen with the naked eye. Dr. McCarthy performed a necropsy on a feeder rabbit in order to show the interns some of the processes as well as what they look at when they try to discern the cause of death. During the necropsy, small samples of each organ are taken and sent to the histology department. Once the samples are delivered to the histology department, they are made into small slides that are stained to be once again examined by the pathologists. A variety of different stains are used in order to reveal cell types, infections, or foreign substances in the animal’s tissues that were too microscopic to be identified during the gross necropsy. If you have ever had your tonsils removed, they would go through a similar process to be made into slides.

What about diseases that can be transferred from non-collection animals that die on Zoo premises? To prevent cases like that from happening, all animals that die near or within the Zoo are examined in the necropsy building. Birds are also placed inside a special hood designed to contain pathogens to prevent bird flu from being transmitted to people. The pathologists are also always on the lookout for the West Nile virus. As you might already know, West Nile virus is spread by mosquitoes and can infect both animals and humans. So the pathologists at the Zoo perform necropsies on non-collection animals to ensure nothing like West Nile can be spread to the animals in the collection or to the human visitors.

The professionals working at the Zoo know all too well how unavoidable death is, which is why Veterinary Pathologists are so valuable in a zoo type setting. If an animal is ill and dies, the pathologists can identify the exact cause of death and prevent disease from spreading to the other animals in the collection. How an animal is treated after they die is just as important as how they are treated alive.

Camille, Real World Team
Week Five, Fall Session 2015