Other Voices

Don’t let Texas deer disease live and spread to humans

A deer forages at the Fort Worth Nature Center & Refuge.
A deer forages at the Fort Worth Nature Center & Refuge. Star-Telegram

Charley Seale, a media spokesman for the American Cervid Alliance, wrote Tuesday of his opposition to tightening regulations designed to better control chronic wasting disease, a newly discovered, inevitably fatal disease in our deer herd (“Texas rules go too far in deer disease fight”).

I want to express my concern as a medical doctor over the pall this malady has cast over the future of whitetail deer in Texas and its implications for public health.

I’m an owner of the 7,500-acre BigWoods on the Trinity hunting preserve, winner of the 2015 statewide Leopold Award for conservation, board certified in internal medicine and cardiology, and a lifelong redneck deer hunter.

CWD is a deer variant of rapidly fatal brain diseases in mammals, the most recent highly publicized human iteration being mad cow disease.

These diseases, including Creutzfeldt-Jakob disease or CJD, the most common yet fortunately still rare variant in humans, were initially thought to be caused by “slow viruses,” but are now known to be spread by prions, abnormal proteins that can somehow replicate themselves.

The epidemic of mad cow disease in England in the 1980s changed our thinking about the transmission of such diseases, as apparently the disease was contracted simply by eating the cooked meat of infected cows. Prions also were found in cow milk and urine.

In my career, I have cared for three patients with these diseases — all three probably CJD, but one perhaps mad cow. As is typical, they were totally demented within a few months and dead within six.

These diseases are all inevitably fatal. They are incurable. The instruments used in treating them are not reliably sterilizable and must be thrown away.

Seale opined that the old regulations to control CWD are adequate, but there is an increasing number of newly discovered afflicted animals.

It is needed and reasonable to test more free-ranging deer for the disease. But to suggest the efforts not be focused on deer-breeding operations, the only places where this pox has been discovered, would be evidence of a basic lack of understanding of epidemiology.

CWD, should it become endemic in our deer herd, would be an utter disaster for the animals themselves, the hunters who seek them, and the culture that has grown up around the sport, not to mention the deer hunting “industry” itself.

But, as a physician, what horrifies me is the possible of spread of this prion disease to humans.

Let me be clear that there is no documented case of CWD spreading to humans, but that is but small solace:

Testing has until recently been possible only when performed on the brains of dead deer. Thus, we almost certainly do not have a definitive comprehension of the breadth of the problem.

What is truly scary is that, in other states, prions have been found in the environment in which these deer have lived and persist for years.

All of these diseases are somewhat different, the incubation of mad cow disease being thought to be between three and 10 years. But this, taken from a monograph on prion diseases from the National Institute of Health, should scare any reasonable person: “In some cases, the incubation period may be as long as 50 years.”

The Centers for Disease Control and Prevention posted this on its website: “Avoid eating meat from deer and elk that look sick or that test positive for CWD.”

CWD must be stamped out in our whitetail herd. Should it get into the wild, the genie cannot be put back into the bottle.

Robert McFarlane, M.D., lives in Tennessee Colony in East Texas.

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