Bloons Disease

"Oh No! Your monkey has Bloons Disease, save him for 10 Monkey Money"

Bloons Disease is what monkeys get when you run out of lives, they will make your monkeys sick and they will die in 40 Rounds, with super monkeys lasting less than 10

How monkeys get Bloons Disease
Each 5 Lives you loose, 1 randomly picked monkey gets Bloons Disease. Even sun gods can get them.

Dart monkeys are the only monkeys that can randomly get Bloons Disease

Also The Stinky Bloon can give bloons disease to any monkey that shoots it