There are a number of reasons why an alpaca may be too thin, many of them life-threatening – so if increasing your alpacas food intake does not cause your alpaca to put on weight, consult your veterinary surgeon! Remember, body-scoring is a valuable tool to check your alpacas condition.
Intestinal worms can cause weight loss, however some alpacas severely affected by worms will be pot-bellied, but otherwise in good condition.
Phosphate deficiency is potentially fatal, and will cause your alpaca to be underweight.
Copper deficiency, also potentially fatal, is rarer, but can also cause thin alpacas.
Scours, or diarrhoea, can cause severe weight loss, and is potentially fatal.
Lactation (feeding a cria) can cause weight loss in female alpacas, especially those who are older, or which have large cria. Feed your hembra with a high protein chaff mix. Vitamin drenches for horses can also help, and many can be added to the feed. Add alpaca nuts to the chaff to increase palatability (taste).