Sounds pretty normal. The only thing I can think of is maybe his food is too rich? My llama lady says they don't do well with legume hay and prefer a lot of roughage.
But I'm just parroting what the local llama lady says. Since llamas/alpacas aren't my main animal, I don't really know. I just ask her questions and do what she tells me. Each year the llamas and alpacas get healthier.