Here's a little news from Reuters that might get you thinking!
Monkey dead from bubonic plague in Denver
Mon May 21, 8:58 PM ET
A Denver Zoo monkey has died of bubonic plague, apparently after eating a squirrel stricken with the disease, Colorado health and zoo officials said on Monday.
Five squirrels and a rabbit found dead on zoo grounds tested positive for the flea-borne disease in recent weeks, Denver Zoo spokeswoman Ana Bowie said.
Read more at: http://news.yahoo.com/s/hm/20070522/us_nm/usa_plague_monkey_dc_1