So, last weekend I castrated a horse. This horse was a "small" 4 yr old draft horse. He hadn't grown as large as the owners expected and wasn't really big enough to use as a stallion. Therefore, they decided to castrate him. A wise choice, since stallions do not make good pets and can be hard to handle.
I arrived on the farm to find my patient waiting for me. His owner has taken him for a little walk and let him eat some grass. He was pretty large, but not as big as a full grown one should be. He had pretty good manners for a stallion and let me examine him ok, but was a little pushy on the ground. I gave him his premedication and walked away to prepare the induction drugs and my instruments.
Castration in horses is in some ways a throwback to "the good old days." Most of them are done in the field under relatively short acting drugs, in this case Ketamine and Valium. My premedications were Xylazine and Butorphanol. When you drop a horse you have to take care the horse does not fall on you. Castration is accomplished with an instrument called, appropriately, an emasculator. This instrument simultaneously cuts off the testicle and crushes the cord it was attached to. This crushes the spermatic cord, the testicular artery, vein, and nerve, and the cremastor muscle that controls testicular descent and ascension. Usually there are no ligatures used. This instrument is left in place for 5 min. My emasculators do not lock in place but must be held in position. Remember this, it's important later.
I approached the horse and gave the induction drugs IV. These drugs are relatively short acting and give me about 20 min to do my job. The horse drops and we rapidly prepare him for surgery. The surgery site is aseptically scrubbed (as much as you can call surgery in the grass "sterile") and I made my first incision. It was remarkably hard to exteriorize the testicle, partly because of this horse's age and partly because there was a lot of fascia. It took me about 5-10 min to get the testicle out far enough to emasculate. While that one was sitting, I got the other testicle out. This one was a lot easier. After the 5 minutes, I applied the emasculator to the other cord.
I guess my 20 minutes was about to run out, because the horse didn't like me cutting his cremastor muscle. As soon as I got the instrument closed, the horse got up.
Horses getting up is a special nightmare in castrations. We're all told horrors in vet school of castrations where horses careen across the field trailing his bleeding spermatic cord and five people running after him. The problem is complicated by the fact that horses can arouse from anesthesia and move without a warning, including things like blinking, reflexes, and other usual indicators of arousal from anesthesia.
I move out of his way (I was in the worst position) and shout to the two guys helping me, "Get him DOWN!!!!" The owner tackles his head and wrestles it to the ground like a bulldogger at a rodeo. The other guys is ready to do the same and the horse than rolls up and sits sternal. Oops. "GET HIM DOWN!" I shout. They then both tackle his head and shoulder and roll him on his side. He starts kicking and flailing his feet as I go behind him and grope between his back legs for the emasculators. Still there, thank God, but did they stay where they were supposed to??? I squeeze desperately as his feet come perilously close to my head. The owner's wife comes out, "Can I do anything to help?"
"Yeah," I reply, "go to my truck and get the black tackle box and the yellow tackle box." I'm telling her to get my drug box and my syringe box. She races back with the requested boxes. Now what, though? I am holding the emasculators and my helpers are sitting on the horses head and neck. How am I to inject this horse??? I look down at my watch. Thankfully, 5 minutes have passed and I can let go of the emasculators. I gingerly removed them, drawing them out of the incision where the creamstor muscle had pulled them, and race to the drug box.
I quickly draw up a half dose of my original induction drugs and slip between my helpers to give the drugs in the jugular vein. His kicking and flailing gradually diminish. I rush around and look at my surgery site. Minimal bleeding is a good sign, but the true test will come when he stands up. Did the emasculators stay on? If he bleeds excessively, I will have to re-anesthetize him and search blindly for the end of the cord. Then I'd have to tie it off.
The horse sleeps peacefully for another 10 min. When I judge the time is right, I take the towel off his head. He blinks for a few seconds, than smoothly rolls sternal and gets up. I peer frantically underneath him. A few drops of blood and some clots greet me, but no gush of blood do I see. I stand back and thank God that I don't have to do anything else to him.
The horse stands there, looks around at me, than calmly puts his head down and starts eating grass.
Thank You, Lord, for sticky emasculators.
4 days ago