Diary of A Fourth-Year Vet Student: Doing The Things!

Some rotations are significantly better than others with respect to doing actual vet things to real animals. In this photo, I am opening up an abscess on the left front leg of a piglet, probably caused by a bite wound from his pen mates as piglets are bitey little things with needle-sharp teeth. A nice pus fountain ensued. This little piglet was lucky--the abscess was outside the joint capsule so he got to keep the leg. I flushed the wound with saline and dilute iodine and we sent him on his way.

This pig is owned by the university. I have been somewhat reluctant to post photos of animals owned by clients. Issues of confidentiality come into play. Lots of clients are quite happy to have us take, and use, photos of their animals. But there is always that one person who will raise a stink.

During that same therio (reproduction) rotation, we had a very interesting surgery earlier in the week on another piglet. He had been castrated at the university swine center, but they could only find one testicle. So they carted him up to the hospital a few days later to see if we could find the other testicle. Everyone suspected it was still inside his belly, as it is fairly common for one or both testicles to not fully descend. Usually they are lurking near a structure called the inguinal ring. Surgery with general anesthesia is required to remove these testicles but it is a standard procedure. We ultrasounded his belly first but could not find a structure that we were sure was a testicle. We opened him up anyway, fully expecting to be in and out in 30-40 minutes tops.

Only one problem: we couldn't find the other testicle. We couldn't find anything that even looked testicle-ish.

After diligent searching for over an hour, all we could find was the structure in the picture below.

This tiny bifurcating structure is a uterus! The large red loops to the lower left are his small intestine, which we had to exteriorize so we could see inside better. They are red because they are getting dehydrated and a bit angry. They were stuffed back into the piglet a few minutes after this photos was taken.

The piglet had retained Müllerian tissues. This is a simplification, but the default state of developing mammalian embryos is female. For male gonads to develop, cascades of several key hormones have to be produced that suppress further development of the female (Müllerian) tissues, cause regression of those tissues, and begin development of male (Wolffian) tissues. The timing of these multiple hormonal cascades is pretty important too. If one of those cascades begins too early or too late, there can be some unusual developmental consequences. In this case, the result was a piglet with a single testicle and a tiny uterus. The piglet lacked the rest of the Müllerian duct (cervix and vagina) and if he had ovaries, they were really tiny. So these tissues weren't ever going to be functional in the sense that they could be used for reproduction. But these kinds of tissues are tricky--they can begin to produce hormones later in the life of the mammal that can lead to metabolic disorders and cancer. So we removed everything we could find.

Biology and physiology are certainly amazing.