– When communities debate what’s best for elephants — zoos or sanctuaries — one subject is almost certain to come up: tuberculosis.

From Toronto to Dallas to Topeka, representatives from zoos as well as zoo industry groups have warned against sending animals to sanctuaries, which they portray as hotbeds of the disease. When officials at Woodland Park Zoo in Seattle decided to send their aging females, Chai and Bamboo, to the Oklahoma City Zoo instead of a sanctuary, TB was one reason cited.

The country’s two elephant sanctuaries have taken in several animals with confirmed or suspected cases of the disease. But TB is by no means exclusive to sanctuaries.

It flared first in circus elephants, with infection rates as high as 40 percent. Since then, TB has shown up in zoos from San Francisco to St. Louis. Three males at Oregon Zoo in Portland were recently diagnosed, and six staff members tested positive for exposure.

But while sanctuaries were quick to embrace the most stringent testing, quarantine and treatment regimes, many zoos — including Woodland Park in Seattle — fought guidelines that several experts say could slow the spread of the disease and lower the risk to elephants and the public.

“I’m not sure everybody involved with elephants is truly vested in eliminating the disease and protecting elephants from infection,” said Dr. Chuck Massengill, former director of the animal health laboratory at the Missouri Department of Agriculture and a contributor to the new guidelines. “I think there were clear indications that some people had vested interests that were diametrically opposed.”

Blood tests to detect infection

Developed under the auspices of the independent U.S. Animal Health Association, the guidelines emphasize the use of blood tests to detect signs of infection before full-blown disease develops.

In some cases, the guidelines would prevent zoos or circuses from transferring suspect animals around the country — a provision that drew furious opposition.

Zoos and zoo associations are challenging the validity of blood tests and arguing the rules would raise costs and unfairly restrict movement of animals. Zoos also downplayed the severity of the problem.

“This disease in elephants is slow-moving, has a low incidence and a low prevalence in the captive elephant population,” said a statement submitted to the U.S. Department of Agriculture by Woodland Park and endorsed by Ringling Bros.

The USDA received nearly 1,600 comments on its 2013 proposal to adopt the guidelines. Most came from members of animal welfare groups who favored stricter standards. Response from the zoo and circus industry was uniformly negative.

The guidelines have not been adopted, though they are still under consideration.

But the Performing Animal Welfare Society (PAWS) sanctuary in California, the Elephant Sanctuary in Tennessee and some zoos have opted to voluntarily adhere to the tougher rules.