Scrubs, Stethoscopes, and Scalpels- The Life of a Vet Student: Reptile Necropsy Lab

This morning was the wet lab I have been waiting for for a year and a half. I wasn’t too excited about having to get up at 7:00 in the morning on a Saturday, but I was willing to do it. Granted, I did fall back asleep after turning off my alarm and didn’t end up waking up until nearly 8, but the good intentions were there, and even though I was a little late at least I didn’t sleep through it!

This morning was the ZEW club’s reptile necropsy lab. By now I’m sure you’re all tired of reading about ZEW club and wish I would talk about something else, but to me exotics are just awesome and interesting and I love learning about them and talking about them.

So this morning Dr. Brad Minson from Banfield came in to give us a short lecture on reptile anatomy, basically just hitting all the main differences between reptiles and mammals, and he brought in some specimens for us to dissect. ( I do want to point out that all of the animals he brought died of natural causes and were donated to us as a learning experience; no animals were bred just for us to necropsy.) I actually wish he had given us a longer lecture, because there was a lot of interesting information. For example, reptiles have a 3-chambered heart (mammals have a 4 chambered heart) and their red blood cells have a nucleus (ours don’t). In mammals, the sciatic nerve runs down the outer part of the leg, but in lizards the sciatic nerve actually runs dorsal to the kidneys (so it is between the kidneys and the back body wall). So any kind of renal disease that leads to enlargement of the kidneys can actually lead to leg paralysis in a lizard. I also learned the most common site for venipuncture in a lizard is the ventral tail vein, which runs right down the underside of their tail. I would never just stick my own lizards, but if any of them ever need blood drawn now I know how to do it. And it’s definitely a lot more tricky than in a dog or a cat, because you cannot see that vein through the scales, so it all comes down to knowing your anatomy.

We also had a ton of different snakes to look at, including 2 rattlesnakes (their heads were wrapped up because their venom is still poisonous even when dead). Snakes are weird. They really are. Their anatomy is so different. We spent a while looking at what we thought was the stomach because it looked like it had rugae and was where the stomach would be in a mammal, only to realize that it was attached to the trachea and was actually the lung. It looks nothing like our lungs. They have trabeculae instead of alveoli, and they have this caudal blind sac that doesn't function in air exchange at all. I have no idea what the point of it is. The arrangement is also different, with the liver coming before the stomach and the gall bladder past the stomach, as opposed to being nestled in the liver like it is in ours. It’s close to the splenopancreas, which is the combined spleen and pancreas organ that snakes have. And all the organs are long and tubular, since they obviously have nowhere else to go. Except for the kidneys, which look kind of lack a stack of coins that was pushed over like dominoes. All lizards have kidneys that look like this, which makes them very distinctive. In a lizard, the organ that looks like a mammalian kidney is most likely a testis. Like I said, it’s weird.

There was also one red-eared slider to look at, which I was really excited about. As I have also mentioned multiple times, I LOVE turtles of all breeds. And they’re so funky, there’s no other animal really like them. Sometimes my husband picks up Soleil just to stare at her and tells her how weird her anatomy is. Yes, he actually does that. But what he sees as weird, I see as fascinating. Turtle anatomy is really unique. For starters, instead of having body compartments that go from head to tail, turtles have compartments that go from top to bottom. So instead of having lungs that take up the cranial portion of the thoracic cavity (which is what mammals have, basically meaning they are closer to the head than the stomach in the abdomen is), turtles’ lungs take up the dorsal third of the body, meaning they take up all the space within the body, just only the top portion of it. And their scapula (shoulder bone) is on the ventral surface instead of the dorsal surface. (Sorry for all the anatomy terms- our shoulder blades are on the dorsal surface toward our backs, while a turtle’s is on the bottom toward its stomach.) And if you were ever wondering, yes, turtles do have ears. But they are sheets of skin stretched out over the otic capsule, there is no external parts like we have. And if you want to find the jugular vein, you kind of have to pull their head out to stretch their long neck out, but other than that it’s in the same place as ours, and can be used for catheterization and venipuncture.

Overall, this was definitely one of the more interesting wetlabs I’ve even been too. It’s one of the more interesting labs I’ve had overall in vet school. I really wish they would give us more exotics work during school, because some of this stuff is just so incredibly interesting. Just how different it is from our own anatomy is interesting. I would love an in-depth lecture on reptilian anatomy. But since I might not get that, I asked Dr. Minson for a copy of his lecture powerpoint, like the nerd I am. Between that, my new turtle dissection guide, and my dozens of pictures from today’s lab I think I’ll be all right for a little while.

A red eared slider- you can see the 2 scapula right by the neck, and the dark mass is the liver.

Bearded Dragon abdomen; you can see some lung, the liver, the gall bladder, and some intestines.

This is the heart and lung of a snake. You can also see the caudal vena cava coming off of the heart.

This is the stomach and intestines of a monitor lizard. You can see the impression from the chicken bone in his stomach (the chicken bone didn't kill him, this poor guy was attacked by a dog).