Story by Craig Nyhus, Lone Star Outdoor News
At the Deer Research Meeting hosted by the Caesar Kleberg Wildlife Research Institute, Dr. Walt Cook, of Texas A&M University’s Department of Veterinary Pathology, updated landowners on the status of an oral vaccine for anthrax effective for use in wildlife.
There is already a vaccine for anthrax, which many livestock owners administer annually, that has been effectively used on livestock since the 1930s. However, it can only be administered by an injection and booster two weeks later, a solution not usually feasible for wildlife.
Livestock owners tried pouring the vaccine over food, but previous testing proved the method ineffective.
“The main issue with an oral vaccine is the ability to keep the bacteria alive in the gastrointestinal tract long enough and in the right amount to produce the desired immune activity in the animal,” Cook said.
The solution involves microencapsulating the vaccine. “It makes it able to get into the system and eventually the blood,” Cook said. “Then the oral vaccine can be put into the food and provide a strong antibody response.”
Cook said future plans are to try the oral and darted vaccines in exotics.
While outbreaks of anthrax aren’t widespread, they are quickly devastating where they occur, usually in areas with a wet spring followed by hot and dry summer. In the United States, it is most common in the western half of the country, where soils are more calcified. In Texas, the Edwards Plateau has some level of it almost every year, and in 2020-2021, an outbreak occurred in the Panhandle, south of Amarillo, where it hadn’t been seen in 50 years.
“It’s the most resistant bacteria known,” Cook said. “It produces toxins in the host and kills it. The spores are highly resistant and remain in the carcass. When the carcass gets opened, the spores are released.”
All mammals are susceptible to anthrax, with grazing species most susceptible, Cook said, and once contracted, die quickly, usually within a few days.
“Anthrax was possibly the source of the plagues in the Bible and possibly the fall of the Roman Empire,” he said.
