Recently I had my Small Animal Procedures lab, in which my classmates and I learned how to perform dentistry, take skin biopsy samples, do trans-tracheal aspirates, take bone marrow biopsies, and a raft of other procedures. I wouldn’t feel comfortable doing any of these procedures unsupervised yet, but I did get to actually do them with my own hands rather than just pick “do a trans-tracheal aspirate” as a multiple-choice answer on a test.
In the past I have described learning on shelter animals that need low-cost procedures, or ex-research dogs that are living at the school until they can be rehomed. This lab used the bodies of animals who had been euthanized at our hospital, and whose owners had agreed to allow us to use them. It is always somewhat disturbing to spend several hours with a dead dog, but this is the one use of animals for teaching that I am one hundred percent happy about. Learning on live animals is never perfect, although my school does its best to find constructive ways to obtain animals for us to use. We had to do so many procedures for this lab, and such invasive ones, that it made sense to use cadavers.
The trans-tracheal aspirate is a particularly interesting procedure to do. The idea is that an animal has some sort of infection in its lungs, and you want to know exactly what. So you thread a catheter into its trachea and down into its small lower airways, pump some fluid in, suck the fluid back out, and test it for bacteria. Okay, but if you thread that catheter in through the mouth, it is going to be contaminated with all kinds of bacteria that you’re not actually interested in, right? So how do you get the catheter in to the trachea without getting mouth bugs all over it?
You stick a big needle in through the outside of the dog’s throat directly in to the trachea, and thread the catheter through that. This means when you stick the needle in, you have to know when its point is inside of the trachea. You can’t see where the point of the needle is, obviously, and that’s why it’s a learning experience. This procedure was particularly hard for me. I kept sticking the needle in, being convinced it was in the right place because I felt a “pop” as it passed into the trachea, and then not being able to thread the catheter in. A tech told me patiently, “if the catheter won’t thread, that means it’s not in the trachea.” Goddammit. I tried again. And again. And eventually it worked.
This was a really enjoyable lab. Four of us worked on one dog cadaver. There were also a few cat cadavers for multiple groups to share. It felt good to do some of the procedures we had learned about, but scary to imagine doing them on living patients in the near future.