Fecal tests are greay, but unless you do them three days in a row you may miss something. I would recommend power packing him. I use the 290g safeguard labelled for cattle. Its cheaper than panacur and the same exact chemical. You can also 5 day worm two horses for around $50! I recently power packed my two year old and his pot belly is going away. Keep in mind he is in VERY light work so the reduction in pot bellyness couldn’t be excercise. Hope this helps!