Written by Cat Reed (’25), CARCAS Lab Manager
According to the Animal Welfare Institute, approximately 20,000 to 50,000 cats are used for classroom dissections each year. These cats usually come from animal shelters after being euthanized, but some are taken off the street or from illegal sources.
Everyone can surely agree that it is extremely sad that so many cats are being killed every year, but there are no simple solutions to this problem. The overpopulation of cats is a serious issue, causing millions of cats to be euthanized every year. The other complication is that dissection alternatives, including computer simulations and 3D models, might be sufficient for middle and high school students, but for students who are going into the medical or veterinary field, dissection is a much more valuable tool.
During the fall term of 2023, I participated in a cat dissection in my Vertebrate Morphology class. When the dissections were finished at the end of the term, it struck me as an unfortunate waste that all of the cats were going to be disposed of. Because of my previous work in the CARCAS lab, I was interested in exploring the possibility of doing a skeleton preparation using one of the cats.
After my professor gave the CARCAS lab permission to take a few cat specimens for the lab, I began the skeleton preparation process and ran into a huge obstacle. There are two main methods of defleshing a skeleton, neither of which were possible due to the preservative chemicals, like formaldehyde, that were injected into the cats for the dissection.
-The first method is using dermestid beetles. This wouldn’t work because the preservative chemicals sterilize the beetles and prevent them from reproducing, which would cause the colony to die out.
-The second method is water maceration. This method relies on anaerobic bacteria growing in the water to break down the flesh. The preservatives prevented the bacteria from growing, which meant that this wouldn’t work either.
After a lot of research and experimentation, I found a solution to this problem. Laundry detergent contains certain ingredients that are able to break down the formalin in the preserved specimens. When the detergent is added to a water maceration bath, the bacteria is able to begin growing.
This is a very cheap and efficient method for defleshing formalin-preserved dissection specimens. Classes that use dissection specimens could easily use this method to add another element of anatomical exploration into their learning. Most in-class dissections are focused on internal organs and muscular systems, but adding the skeletal system to the dissection process would be incredibly valuable for those studying anatomy.
Additionally, these defleshed skeletons could easily be put through the remaining steps of the bone-cleaning process and then be stored and kept permanently in classrooms or donated to other classes. I think that this is a great way to make the most out of the complex issue of dissection specimens.
