By WHITNEY ROYSTER
Star-Tribune environmental reporter
JACKSON -- Domestic cats have been identified as carriers of bubonic plague in Wyoming before, but the deaths of four mountain lions to the disease this fall are a newly observed phenomenon, officials say.
Three infected mountain lions, including a female and its kitten, were collared animals and part of a research project by Beringia South of Kelly, a group looking at the relationship between mountain lions and wolves. The fourth lion last year was a 10-year-old collared female and was part of a study by the Wildlife Conservation Society.
According to Cynthia Tate, assistant veterinarian for the Wyoming Game and Fish Department, the cougar with the kitten that had the plague also had another kitten in the litter that did not have the disease.
"We don't know if the other kitten was exposed and survived," she said in a news release from the University of Wyoming. "A question that intrigues me is how many exposed cougars actually get sick, and what is the ultimate outcome? What is the proportion of sick cougars that die versus those that recover?"
That kitten is in the Game and Fish Sybille Research Center near Wheatland. Tate also said biologists who discovered the dead mountain lion and her kitten were potentially exposed to the plague, but are doing fine.
The disease responds to antibiotics, but many people don't know they have such a serious disease and delay treatment for themselves or their animals.
"If (a cat) has swollen lymph nodes, and you can't find where it's been in a fight, I would get it to a vet," said Ken Mills, a professor in the University of Wyoming College of Agriculture's Department of Veterinary Sciences. "If your cat's coughing, get it to a vet, especially if it goes out near rodents."
Mills also said people should get flea control for their cats, especially if they go outside. In the winter, rodents can come inside, so flea control is a good idea now, too, he said.
Tammy Hunt, Teton County public health coordinator, said news of the bubonic plague in wildlife "hasn't hit my radar," but said it isn't unusual for the disease to be present in wildlife.
"It is fairly normal to see it present in a couple of domestic cats in states like Wyoming and Montana a year," Hunt said. "In my past experience, I've never seen it threaten humans when it's in the animal reservoir like that."
Still, anyone with symptoms should see a doctor or veterinarian. They include swollen, tender lymph nodes, fever, chills, coughing and sneezing.
Dr. Jamie Snow with the Wyoming Department of Health said the plague has been documented throughout the state, but the number of cases differs from year to year.
"We tend to see it every year in low levels in wildlife," she said. In Wyoming, the last reported case of the plague was in 2004 and was carried by a Colorado resident who contracted the disease skinning a rabbit in Wyoming, she said.
There have been five cases of the plague in humans in Wyoming since 1978, according to the Department of Health. They were in Goshen, Laramie, Sheridan and Washakie counties. In 1992, the Sheridan County case resulted in the death of a man who contracted the disease after skinning an infected bobcat.
The incubation period is between two and six days. But, Mills said, people might not know when they were infected, as fleas can live in an environment for a while, then bite a person or animal.
There have been at least seven cases of the plague in domestic cats in Wyoming in the past year, Mills said. They included four in Laramie County and one each in Albany, Natrona and Teton counties.
A call should first be made to a doctor or veterinarian instead of walking into an office unannounced so precautions can be taken to avoid exposing other people or pets to the disease, Mills said.
Snow said hunters should not kill any animals that look ill -- a rough coat or eye drainage -- and people should wear gloves and wash with soap and water after treating any animal.
Snow also said dogs and cats should have flea protection, but fleas are more of a problem in spring and summer than now.
In the Middle Ages, the plague wiped out populations across Europe. It was so rampant because of high rat populations in urban centers carrying fleas and the plague.
The United States has 10 to 15 cases of the plague in humans annually, according to the Centers for Disease Control and Prevention.
Environmental reporter Whitney Royster can be reached at (307) 734-0260 or at firstname.lastname@example.org.