Disposal by incineration is preferred; however, deep burial is also an acceptable method. There may be some jurisdictional restrictions on incineration or deep burial.
Evaluate each animal before disposal, and ensure that all body openings are plugged with an absorbent material (e.g. non-perforated paper towel, cloths, etc.) before a carcass is moved.
Note: It is important to record the land location (e.g. global positioning system [GPS] coordinates) for all burn and burial sites.
Note: Research has shown that using lime or other calcium products on carcasses or contaminated ground is contraindicated. Calcium has been shown to protect, rather than destroy, anthrax spores. AVOID USING LIME or other calcium products on carcasses or contaminated ground.
A. Prevent Escape of Bloody Exudates from the Carcass
Note: AVOID performing an autopsy when anthrax is being considered:
- Ensure that all body openings (e.g. anus, mouth, nose, etc.) are plugged with an absorbent material (e.g. non-perforated paper towel, cloths, etc.) to prevent leakage of exudates.
- Ensure that the entire head is covered with a heavy duty plastic bag that is secured at the neck, behind the ears, and across the poll with duct tape, or tied with rope or twine.
Move the carcass on a conveyance that can be destroyed with the carcass or easily cleaned and disinfected (e.g. wood pallet, etc.).
AVOID USING LIME or other calcium products on carcasses or contaminated ground.
B. Protect Carcasses until their Disposal
To prevent scavenging and spreading of spores by insects, birds, or mammals, once all body openings are plugged and the head securely covered, cover the carcass with a tarp, heavy plastic, or other appropriate material. Weigh down the edges of the covering to prevent removal by wind or predators.
The natural decomposition of a carcass destroys most of the vegetative anthrax organisms within 48 to 72 hours in warm weather conditions. These carcasses pose a smaller risk of environmental anthrax contamination during subsequent handling for disposal. The carcass, however, may be friable, and thus may easily pull apart, posing other difficulties in handling.
C. Incineration/Burning C Pyre or Pit
The following guidelines provide information on evaluating disposal efforts and in confirming complete incineration.
The goal is to destroy as many spores as possible, thereby decreasing environmental anthrax contamination. A complete burn should be achieved. The carcass should be completely reduced to ash. An effective burn primarily leaves ash and bits of bone, with minimal fly attraction to the site.
General considerations:
- Incinerate or burn by either pyre or pit, which is the preferred method of disposal (particularly when a carcass has been inadvertently opened for post-mortem examination or scavenging).
- Be aware that burn permits may be required by municipal or provincial governing authorities.
- Know that there may be jurisdictional restrictions on materials used in incineration or burning efforts. (British Columbia, for example, prohibits the burning of railroad ties.)
- Be aware that ventilation and adequate airflow within a pyre or pit are essential. Prevailing winds should be considered in providing a good supply of air to the fire.
- Understand that, if the fire burns too quickly, a complete burn will not be achieved, necessitating a secondary burn.
- Avoid using materials that may be environmentally harmful (e.g. rubber tires).
- Ensure that an adequate amount of fuel is available to completely reduce the carcass to ash.
- For complete incineration, add any carcass parts or materials that fall off a pyre during the burn back onto the fire.
- Burn contaminated materials with the carcass.
1. Pyre System:
a) Wood
- Bottom layer: large-sized logs, fence posts, railroad ties, wood pallets spaced 8–10 inches (20–25 cm) apart in a criss-crossed fashion to allow air to enter the fire from below. Align these materials with the direction of the prevailing wind.
- Middle layer: smaller pieces of wood or coal placed over top of the bottom layer.
- Top layer: prop up the carcass to lay it on its back, placing any soil that is potentially contaminated by the animal/exudates on top of the pyre.
- Kerosene or diesel fuel (accelerant) to soak down all the materials (approximately 5 gallons or 23 litres per carcass).
- Light the fire from two opposing ends of the pyre.
Note: Approximately one cord of wood (4' x 4' x 8' or 128 cubic feet; 1.2 x 1.2 x 2.4 or 3.4m3) is required per 1000 lbs (~ 500 kg) of carcass to be incinerated.
b) Straw
- Bottom layer: large-sized logs, fence posts, railway ties, wood pallets spaced 8–10 inches (20–25 cm) apart in a criss-crossed manner to allow air to enter the fire from below. Align these materials with the direction of the prevailing wind.
- Middle layer: two large round bales per carcass, approximately 1200 lbs (545 kg) each. The bales can be laid on their sides or placed on end. Place a layer of wood pallets on top of the bales to make a platform for the carcass. Pallets wedged between the bales will increase airflow into the pyre.
- Top layer: prop up the carcass to lay it on its back, placing any soil that is potentially contaminated by the animal/exudates on top of the pyre.
Note: Flax bales burn at a very high temperature and are well-suited for burning carcasses; however, when used as the sole fuel, they may burn too fast for effective incineration of the carcass. Using flax bales in the centre of the pyre surrounded by other straw bales will burn hot enough for complete carcass incineration. When other types of straw bales are used as the sole fuel source, more accelerant will be required.
Note: An effective burn primarily leaves ash and bits of bone with minimal fly attraction to the site.
Soak the ashes with acceptable disinfectant. AVOID USING LIME or other calcium products.
Decontaminate any contaminated ground that is associated with the carcass disposal by using a torch and/or soaking with acceptable disinfectant. AVOID USING LIME or other calcium products.
2. Burn Pits/Trenches
The use of a pit facilitates the burial of ashes and prevents fire from spreading. Sloped sides on the pit facilitate airflow to the fire.
Burn pit/trench considerations:
- For a mature animal, the pit should be 18–20 inches (0.5 m) deep, and extend approximately 2.5 feet (0.75 m) beyond each end of the pyre that will be constructed.
- The pit should be approximately 10 inches (25 cm) wider than the pyre on each side; this allows airflow around the carcass.
- The bottom of the pit is covered with accelerant (e.g. diesel fuel, kerosene, etc.), soaked straw, or wood, etc., placed in such a way that facilitates airflow.
- Pieces of heavy timber (or other beams) are placed across the pit to support the pyre.
Note: It will be necessary to decontaminate the ground where the carcass lay, as well as the equipment, tools, etc. used in handling the carcass and any contaminated materials. Decontamination is carried out by burning the area, using a propane torch and/or soaking with an acceptable disinfectant. AVOID USING LIME or other calcium products.
In all cases, assess the burn site to ensure that there was adequate incineration of the carcass.
D. Burial
If incineration is not feasible or cannot take place immediately, deep burial may be a viable option.
Note: The location of burial sites, using GPS or other mapping methods, should be recorded by those involved, and kept indefinitely.
Burial considerations:
- Be aware that burial permits may be required by municipal or provincial governing authorities.
- Require heavy excavating equipment (i.e. backhoe) to dig a suitable hole.
- Ensure that the pit is 6–8 feet (2 m) deep – the bottom of which should be well above the water table (minimum 3 feet (0.9 m).
- Consider the water table level and soil composition – clay soil is preferable, whereas, sand or gravel should be avoided.
- Have a minimum of 3.2 feet (1 m) of clay at the base of the pit, and cover the carcass with a minimum of 3.2 feet (1 m) of clay and topsoil to prevent access by scavengers.
- Use 10% formalin or 5% lye solution (sodium hydroxide), or another acceptable disinfectant, to decontaminate the carcass and all soil put into the burial pit. AVOID USING LIME or other calcium products.
E. Rendering
Moving infected carcasses to rendering facilities poses too great a risk of spreading disease; therefore, rendering anthrax-contaminated carcasses is contraindicated. Rendering is not a recommended method of disposal of carcasses (in whole or part).
F. Delayed Disposal C Special Circumstances
Under specific environmental conditions – for instance, prolonged rain; carcass inaccessibility (e.g. standing water, heavy bush); or logistical problems (e.g. lack of proper equipment, manpower etc.) – the prompt disposal of infected carcasses may be impossible. In these circumstances, to prevent or minimize anthrax environmental contamination, assess the situation to decide on an appropriate course of action within a realistic timeline for disposal. Cover the carcass and the surrounding area with disinfectants, such as 10% formalin or 5% solution of lye (sodium hydroxide), and repeated as needed. Protecting the carcass from scavenging is also indicated. AVOID USING LIME or other calcium products.