In their natural environment, alpacas move to pasture daily, move around to graze and then move back from pasture to shelter at night. Moreover, some of them go for miles to get to their pastures. If your pastures are designed so that your animals can move around, especially up and down some hills, they will at least get some exercise. This is certainly preferable to the alpaca that just hangs out waiting for the next serving from the pizza bar. Besides the added stress of obesity on the joints, obesity causes the heart to work harder and can result in poor reproduction and poor milk production.
Obesity does appear to run in some alpaca families.
When selecting alpacas, the negatives of choosing an animal from an obese family may outweigh the plusses that may exist in the animal such as great fiber. Every time you are working with an animal, you should perform a body-score assessment and make a note in its record. Abrupt changes in weight are always of concern. Separating the fat animals and putting them on a weight reduction plan is paramount. As the weight loss experts tell us, slow and steady weight reduction in an organized program is the way to go.