Chronic Wasting Disease
What Is CWD?
Chronic Wasting Disease, often referred to
as CWD, appears to be a prion disease that
attacks the central nervous system and causes
fatal damage to the brain of white-tailed
deer, mule deer and Rocky Mountain elk.
What Are the Symptoms of CWD?
In the later stages of infection, deer and elk
infected with CWD will show signs of progressive
weight loss, listlessness, excessive saliva-tion
and urination, increased water intake,
depression and, eventually, death. Animals
can be infected with CWD for months or years
before outward signs of infection are evident.
What Causes CWD?
The exact cause of CWD is not known at
this time but the best scienctific minds in the
country feel that it is a prion disease. A prion is
a mutated protein in the body that causes
other normal proteins to fold abnormally and
cause sponge-like holes in the brain. A growing
body of research evidence indicates that
this prion is the causative agent for CWD. The
origin and life cycle of these prions are the target
of ongoing research aimed at ultimately
developing a management plan to eliminate, or
at least contain, the existence of these prions
in both wild and captive herds, as well as in the
environment.
How Is CWD Transmitted Between Animals?
Although the exact method of transmission
is unknown, it is known that CWD is transmitted
from animal to animal. In all probability, the
transmission is through body fluids like feces,
urine or saliva. Animals that are crowded or
confined have a greater chance of encountering
the body fluids of other animals and, therefore,
a higher likelihood of becoming infected if
the rogue prion is present. Animals that have a
social system that includes close contact with
herd mates also have a higher chance of
becoming infected. There is a high possibility
that CWD prions can survive in the environ-ment
after infected and exposed animals are
removed.
Where Does CWD Occur?
CWD is a disease unique to North America.
On our continent, it has been found in wild
deer and or elk in Colorado, Wyoming,
Nebraska, South Dakota, Wisconsin, Saskatchewan,
and now in Utah.
In captive deer and or elk, it
has been found in Colorado, Montana, South
Dakota, Oklahoma, Kansas, Nebraska,
Saskatchewan and Alberta.
How are Animals Tested for CWD?
Currently, the only acceptable test is a
microscopic examination of an animals brain
stem. To do this, the animal must be dead.
There is no currently accepted live test. A tonsil
test has been developed but is yet to be validated by the scientific community. Additionally,
tonsil tests are not practical to use on wild animals
as they must be tranquilized and held in
captivity until results are known. All tests currently
used or being examined require a
lengthy turn-around time, usually eight to ten
weeks before results are known.
Can Humans Be Infected with CWD?
There is currently no scientific evidence that
CWD has or can spread to humans, either
through contact with infected animals or by
eating the meat of infected animals. The
Center for Disease Control has conducted an
exhaustive study of CWD and human risk and
has stated: "The risk of infection with the CWD
agent among hunters is extremely small, if it
exists at all". However, as we are still learning
about this disease, the Commission recommends
that hunters take precautions to limit
risks. First and foremost, do not harvest any
animal that appears sick or is acting strange.
Note the animal's location and contact the
Commission. Avoid cutting or puncturing the
spinal cords or brains of animals taken in the
areas where CWD occurs. Do not use house-hold
utensils to field dress or process your
deer. Wear rubber or latex gloves when handling
any harvested animal.
Can the Disease Spread to Other Animals, Such As Cattle?
Again, there is no indication or scientific evidence
that the disease can spread to species
other than deer or elk, but research in this area
continues. Studies have shown that cattle
placed in close and confined proximity with
infected deer and elk have not developed the
disease.
How Common Is the Disease?
As more extensive steps have been taken to
learn more about the disease, its spread, and
its prevalence in both wild and captive deer
and elk herds, the body of evidence continues
to grow. It was once thought that the disease
occurs naturally in less than 5 percent of the
wild deer population and in about 1 percent of
the wild elk population, largely based on studies
conducted in the infected areas of Colorado
and Wyoming.
Can hunters have their deer/elk tested for CWD? Utah Only!
Hunters who wish to have their deer or elk tested
for chronic wasting disease may do so at a cost of $20 by providing
the head of the animal to Utah State University Veterinary Diagnostic
Lab in Logan, Utah. Deer and elk must be older than one year to be eligible
for testing. Hunters interested in having their animal tested should call the lab at 1 (435) 797-1895.
For more info about CWD click here
Chronic Wasting Disease Alliance
