The Three-Minute Outdoorsman: Wild Science from Magnetic Deer to Mumbling Carp

9. My Deer Doctor

t h e t h r e e - m i n u t e o u t d o o r s m a n 42 this is hypothetical as you couldn’t enforce it or expect hunters to distinguish a 129-inch from a 131-inch buck in the field. But there would need to be a way to get some bucks through the slot to provide enough mature bucks to maintain superior genetics. In the end, I think our efforts to enhance the habitat and survival of deer probably outpace whatever negative effects occur to antler size because of removing the prime reproductive males. At least the photos of huge-antlered bucks in magazines suggest that. But I’m glad deer are not like bighorn sheep, and I’ll think twice about harvesting even a nice two-year-old buck. The does are better eating anyway, especially the younger ones, which raises the question of which does we should harvest, a topic for another time. 9 my deer doctor take two acorns and call me in the morning To my knowledge, I have never seen a deer that was “under the weather,” in the same way that you can tell someone has a cold or flu. I’ve not seen a deer just lying around looking crummy, sneezing and whiffling, sitting next to a pile of used tissues. This observation leads me to wonder if deer get sick. That curiosity led me to do some digging about what illnesses and parasites deer get. It turns out that if you wanted to be a deer doctor, you would be expected to know about viral, bacterial, and rickettsial diseases as well as parasites like protozoa, trematodes, nematodes, cestodes, and arthropods. Pretty much you would need to be up on the diversity of life and be an expert in treatment of disease. Much of what follows comes from T. A. Campbell and K. C. VerCauteren’s chapter “Diseases and Parasites” in the book Biology and Management of White-Tailed Deer (ed. D. G. Hewitt, CRC Press, 2011). A L L T H I N G S D E E R 43 Deer get Chronic Wasting Disease (CWD) and bovine tuberculosis . These two diseases are very different. CWD is caused by a naturally occurring protein that changes its shape (then called a prion) and interacts with other normal proteins, causing them to change their shape; they build to a level sufficient to clog the central nervous system, especially the brain, resulting in death. Prions are not like other disease agents—they are not alive, they don’t mate or reproduce—they are more like an environmental toxin. That means that making a vaccine to protect against prions may not be possible, any more than making a vaccine to protect against cyanide poisoning. Tuberculosis is a more typical disease in that it’s caused by a bacterium. It occurs in humans and is one of the most common infectious diseases worldwide. Bacteria can be killed by antibiotics , and we’ve done a good job of controlling tuberculosis in people. Because a bacterium has genetic material and is capable of reproducing, it is very different from a prion. It can evolve so that it is resistant to vaccines and antibiotics. You get a new flu vaccination every year for the same reason—the influenza virus evolves so rapidly that last year’s flu shot may not provide immunity. The main concern with bovine TB is that it can be spread by oral or respiratory routes, such as via contaminated feed, mutual grooming , or inhaling infected droplets from sick animals. This disease is very bad for both deer and cattle. A nasty viral disease is hemorrhagic disease (HD), which is caused by a special virus called an “orbivirus.” There are more than 120 “strains,” which fall into fourteen major groups, but only a couple are really bad for deer. The disease is spread by several species of midges (so you have to be an entomologist). HD is the most important viral disease of deer, but population-level effects are not well documented. Also, it’s not zoonotic, meaning it is not transmissible to humans, so it hasn’t received our undivided attention. Deer with clinical expression of HD can exhibit depression (you have to be a deer psychiatrist too), emaciation, facial swelling, fever (thank goodness for the old thermometer), lame- t h e...