It is well known for many years that squirrels in California have the plague. Apparently we dont get enough cold weather to kill the virus.
Actually it’s the fleas on the rodents that spread the plague.
We do here in Nor Cal, where it get down to below zero during the Winter. No fleas here.
There are plenty of prairie dogs in Texas with it.
It is not a virus.
It is easy to treat if caught soon enough.