We immediately diagnosed the problem as improper handling of the gerbils. A thin skin covers the gerbil s tail. Unlike rats or mice, if a gerbil is picked up by the tip of its tail, the skin will often slip off. The exposed tail is left raw and eventu ally becomes necrotic. The reason for this is not known, but researchers have speculated that it is a defensive adaptation useful in escaping predators 1 .
Chinchillas exhibit a predator avoidance mechanism known as fur slip.
When the animal is fighting or roughly handled, it can release a large patch of fur, thus enabling it to escape. A clean smooth area of skin is left, an d hair may require several months to regrow. We anesthetized the gerbils that had lost their tail skin, and then surgically amputated the bare tails where the skin ended. We then carefully instructed the new technician in the proper methods of handling a gerbil. Care must always be taken when pi cking up a gerbil to avoid grasping the tail unless it is gently held at the base.