What happens if an animal is not fit?

It gets fat der!!

Probably didn't listen to Doctor Michael.

Well, in the wild, it's survival of the fittest. So, if it is not fit and one day, it needs to be, but isn't, it will get caught, killed and eaten. Or eaten before being killed.

Man, is the only animal that supports its members that are not fit, by determining why and how to repair that. Its something new, called Medicine, and the practioner of that is called a 'Doctor", a "Nurse" and the diseased ones are called "Patients", and must be patient and get doctored and be nursed back to health.

You know, 'back to health', 'from being sick', so they are 'going back', or walking back, like Michael Jackson, when he did the "MoonWalk".