The days are getting longer and warmer and as the world starts to wake up from winter hibernation it is time to start thinking about one of the problems our feline companions can encounter in this area. Cats that go hunt outside throughout the southwest are always at some risk for coming in contact with plague, a disease caused by a bacterium called Yersenia Pestis, which can have serious implications both for cats and their owners.
Most rodents in this area, and prairie dogs in particular, act as a natural reservoir for low levels of the plague bacterium. The general ammount of plague in the local rodent population tends to rise and fall on an approximately 7 year cycle.
Rodent populations are also common hosts to fleas. Fleas are not terribly enamored of our high altitude and dry climate, but moist, warm rodent burrows make a cozy hideaway with a well stocked pantry of warm bodies to keep flea populations thriving.
When a flea bites a rodent that is carrying the plague bacteria it sucks up some of the bacteria along with its blood meal. The next animal that flea bites then gets injected with a dose of plague bacteria as a bonus to go with the red, itchy bump they usually get.
Dogs are remarkably resistant to getting sick from plague, but they could act as transportation to bring infected fleas into the house. Cats are not so fortunate. They become severely ill and often die when infected with plague. The symptoms include a sudden, very high fever, and often extremely swollen lymph nodes on the neck, under the jaw. Many ordinary antibiotics effectively kill the plague bacteria, but often the damage is so rapid and severe that even if the bacteria are killed, the destruction they have caused is too overwhelming for the cat to survive.
There are several ways that cats can come down with plague. They can eat a rodent that is carrying it, they can eat a contaminated flea, or they can be bitten by a flea that is carrying the organism. Like dogs, cats can also ferry contaminated fleas into the house, potentially exposing the people inside to the disease, and as large swaths of the European population in the middle ages can attest, plague makes people sick too. Fleas are very sensitive to changes in the body temperature of their host, and as the body temperature of the mouse the cat has just killed starts to drop its fleas start abandoning ship in droves, looking for the closest warm body to jump on. That warm body is usually the cat who is proudly carrying around his dead mouse prize. Those fleas might later be persuaded to try human blood if it is just a short stroll from the cat to your lap, where the cat is sleeping. Don’t say the cat never gave you anything.
The most effective way to reduce your cat’s exposure to plague, as well as your own, is to keep her inside. Cats that go outside will at least be protected from being bitten by infected fleas and prevented from bringing little hitchhikers back inside if they are treated with reliable flea preventatives like Frontline or Revolution, not those toxic and relatively ineffective flea collars that are available over the counter at pet supply stores.