To the best of our knowledge, this represents the first reported case of plague in a llama. There are reports of plague in camels and a mule deer. The New Mexico State Office of Public Health investigated this case. Three pastures at this facility were found to have prairie dog colonies. The pasture where the infected llama resided had evidence of a prairie dog colony die-off.
Prairie dogs are highly susceptible to the infection and entire colonies can be destroyed.
Cultures of captured fleas from this farm were negative for Y. pestis . The public health officials presumed the llama contracted the disease from bites of infected fleas of prairie dogs. Birds, bears, skunks and dogs are relatively resistant to infection with Y. pestis while camels, goats, deer and cats are more susceptible and may serve as a source of infection for humans. Burrowing rodents, such as rock squirrels and prairie dogs, are ideal reservoir hosts for Y. pestis because their social structure allows easy transfer of infected fleas to a large population of new, susceptible animals. The pathogenesis depends on how the organism enters the body.