By John M. Tomeček
Assistant Professor and Extension Wildlife Specialist, Texas A&M AgriLife Extension Service
The most important practice for managing Chronic Wasting Disease (CWD) is to prevent the movement of prions (which cause CWD) to new areas. Because infected carcasses can be a source of this disease-causing material on the landscape, it is critical to create a barrier between infectious tissues and susceptible species. Prions appear to remain infectious in the environment for long periods of time so the barrier must be as effective and long-lasting as possible.
Carcasses from areas with CWD should never be disposed of on the landscape in non-CWD areas.
Carcass disposal practices
It is essential to dispose of carcasses in way that limits exposure of susceptible species to prions and prevents the movement of infectious materials to other areas. The following are practices that the public can use to safely dispose of carcasses.
1. On-site disposal
One practical method is to bury the carcass at the kill site. Burial should be deep enough to prevent scavengers from digging up the carcass and removing it. In practice, limiting access of carcass parts is the most important aspect of burial.
A single trench can be used throughout a hunting season. After carcass parts are deposited, a layer of soil may be laid over the parts to limit scavenger exposure. At the end of hunting season, the trench should be filled in completely.
b. Landscape disposal
If burial is not possible, you can dispose of carcass parts at the site of harvest. This should be done as close to the kill site as possible without removing infectious tissues from the site. Landscape disposal is the least preferred disposal method within a CWD zone because it does not help prevent future infection on that location. However, this method does minimize the chance of moving CWD to areas it did not previously occur.
2. Off-site disposal
a. Landfill or trash service
The preferred off-site disposal location is an approved landfill. Using this location typically involves transporting the carcass to the landfill, or depositing it in an approved trash service’s container. Carcass parts are then buried deep in the earth—this should create a permanent barrier against future infection. It is essential that the landfill or trash service be approved and willing to accept carcass parts from hunters. The Texas Commission on Environmental Quality (TCEQ) maintains a list of in-state facilities that are permitted to accept carcass parts.
b. Incineration or chemical digestion
Though incineration or chemical digestion are the optimal methods of carcass disposal, the needed facilities are usually found only at research facilities or laboratories and may not be available to private citizens.
1) Incineration requires temperatures in excess of 2000 °F, which is typically achieved in a crematorium. Pasture incineration is unlikely to expose the entire carcass to adequate sustained temperatures. Pasture incineration is also problematic because residual ash must also be disposed of properly.
2) Chemical digestion is a method used by research facilities and diagnostic laboratories to safely dispose of infectious tissues by using high concentrations of sodium hydroxide. The equipment required for this method is expensive and the required permits are difficult to obtain. If you think you can conduct either of these methods privately, consult with a regulatory official to be certain you are in compliance with state and federal laws.
Proper carcass handling
Although there is no proven susceptibility of humans to CWD, deer sometimes carry other diseases that can be spread to humans. All hunters should observe the safety precautions listed below when processing wild game.
- Cover all open wounds.
- Wear latex or rubber gloves when processing game.
- Keep mouth and nose covered.
- After processing, disinfect tools with 2 parts household chlorine bleach to 3 parts water solution. Rinse well with water.
- For CWD concerns, debone and remove all nervous system tissues (Diagram 1). – Use separate instruments to cut meat, and bone and/or nervous system tissue. If you do not process your own carcass, consider asking your processor to process your animal individually.
Remember, state regulations determine when and to what degree carcasses may be processed. These instructions are designed to limit the spread of CWD—you should always follow local game laws as well. The following website includes carcass importation regulations for many states: http://www.ncwildlife.org/hunting/cervid-carcassregulations
If you see a sick deer
Any wild animal that appears ill or behaves abnormally should be reported to your local Texas Parks and Wildlife Department biologist or game warden. Although it may not be CWD, it could be the symptoms of an outbreak of some other disease, such as anthrax or blue tongue. Hunters’ observations in the field are the most important resource for managing diseases of Texas wildlife.
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