Federal wildlife officials will test a toxic bait for invasive feral swine starting this year.
The Department of Agriculture's Wildlife Services secured an Environmental Protection Agency permit to start field trials on sodium nitrite bait for free-roaming feral swine in Texas and Alabama. The bait could become available by 2020 to Wildlife Services–licensed applicators.
Sodium nitrite is a preservative used to cure sausage and bacon. In swine, high doses cause clinical effects similar to those of carbon monoxide poisoning, usually progressing from lightheadedness to death within three hours.
Separate information from APHIS indicates pigs have low concentrations of the enzyme methemoglobin reductase, which makes them sensitive to nitrite-induced methemoglobinemia.
The bait could be attractive to raccoons, bears, and deer, the announcement states. Wildlife Services researchers will design bait and delivery systems for feral swine and place them in areas without known black bear populations.
About 6 million feral swine live in 35 states. They cause about $190 million in damage to crops each year.
A Wildlife Services fact sheet indicates feral swine will metabolize most of the sodium nitrite eaten. Remaining sodium nitrite in carcasses will break down and pose limited risk to scavengers.
APHIS information indicates sodium nitrite has been used to kill feral pigs in Australia under the trade name Hog-Gone. The USDA and Australian government have concluded it is humane.