Student Experiences

Submitted by Lauren Bynum, Texas A&M University

Chemical Immobilization of Whitetail Deer for Dummies (& Vet Students)

As part of a wild game elective at the Texas A&M College of Veterinary Medicine, we were given a choice for our semester project: acquire your Hunter’s Education Certificate, or come up with an alternate wild game related group project. The decision was easy–hours of work on your computer or go do some hands on work with your friends and some critters? Hands on, yes please!

My group had the opportunity to learn how to chemically immobilize whitetail deer at a breeding ranch near Kerrville in order to help with deworming and tagging. I was stoked; growing up near ranches, I had heard about the darting process in passing, but I never had the chance to be a part of it. We learned that safely immobilizing deer via darting starts way before sedating the animal; it starts with hunter safety and knowing how to safely handle a dart gun! Getting hit in the foot with a projectile from an actual rifle would hurt like crazy but getting hit in the foot with a projectile from a dart gun could mean potential death depending on the drug dose involved. Once everyone was comfortable handling a dart gun and the darts themselves, it was time to prep the drugs! These deer were immobilized with something called BAM (a combination of butorphanol tartrate, azaperone, and medetomidine HCl). A “Pneu-Dart” is used to deliver the drugs: a cartridge fired projector delivers the sedative after making contact with the fawn (or the ground, depending on how good a shot you are!). After darting a fawn, the group would monitor it as it went down. The fawn will fall down quickly after it takes its first bad step, where it begins to stumble. The time from darting to being completely down is only 10 minutes, but even once down, it is important to approach the fawn slowly and quietly from behind. 

Once down, the inner ear of the deer was tickled to ensure it was completely down, and if it kicked, we would give the BAM a little longer to work its magic. Then, the eyes were covered with a towel to serve as a blindfold, and the tongue pulled out the diastema to ensure the airway was open. It’s amazing what a difference a blindfold can make in keeping a deer calm, even in a not fully sedated deer. To maintain the fawn’s body temperature at safe levels, the fawn was then moved onto an insulated mat. Darting at this ranch is typically completed in the winter, and fawns lose heat fast when sedated. Throughout the deworming and tagging process, the patient is monitored–but unlike clinics and hospitals where there’s fancy anesthesia equipment helping out, out on the ranch, monitoring is done the old-fashioned way: with your own eyes, ears, and hands. We monitored the respiratory rate, capillary refill time, and heart rate while the patients were sedated. On the mat, the fawn was placed in sternal recumbency, the blindfold pulled up quickly to administer eye drops for lubrication, and then it was time to move on to the reason we darted them in the first place!

A small amount of bleeding typically accompanies darting, and the wound was flushed with hydrogen peroxide then treated with an antibiotic gel to prevent infection of the dart site. An injectable antibiotic, in our case, oxytetracycline, was then given to reduce the risk of infection of both the dart site and the ear tagging site. Next up, ivermectin was administered subcutaneously to reduce the intestinal parasite burden in the young fawns. And finally, the ears were tagged. The ideal tagging location for this ranch is approximately one quarter of the ear’s width in from the lateral side, about halfway up the ear. After the device is squeezed and the tag is on, rotate the tag to make sure it is properly attached.

Finally, it is time for reversal and recovery! The area directly around the fawn was checked and cleared of potential hazards – can’t have our sleepy deer jumping straight into a cactus! A mixture of reversal agents (atipamezole and naltrexone) was then administered intramuscularly. We removed the blindfold and monitored the fawn throughout its recovery. The average recovery time is 15 minutes, but we were told that the maximum time can be up to a half hour. In what seemed like no time, the sleepy fawns would open their eyes, lift their heads, and then fly away from us, happy to return to their families. 

Though we have hands-on labs almost every week at school, the opportunity to go learn by doing out on a ranch itself was invaluable. Our ranch excursion was equal parts fun and informative, and it really emphasized the importance of being able to adapt to the surroundings you’re in. An animal that’s brought to a clinic is likely going to have different needs than a whitetail deer out on a ranch, but both are equally worthy of receiving quality care and respect. I’m so glad my peers and I had the opportunity to learn more about how to best treat animals in a less structured setting.