Yes, that awful smell of decaying made me remember a necropsy we did on a hen that died to an infected gut caused by bacteria. The gut swelled up and started twisting not letting anything pass.
Call your local vet and ask if they will do a fecal float exam, it should only cost about $20 and could tell you if you even need to treat for worms. If the problem is cocci or a bacterial disease a different approach would be called for. Another benefit is if it was only roundworms a one-day...
That is a good point and should be taken into consideration, but don't worry about overdosing, Kathy has given ten times the dosage and had not seen any ill effects.
A one fay dose will kill roundworms, to get all types of worms you need to do the five day treatment. I would do both birds at the same time and schedule although the hen needs two ml per day.
Yes Q8 is right on, the dosage for mature peafowl is 2 ml for a hen or three ml for a cock. Ml and cc are the same. Give for five days and then another round ten days later to kill the worms that hatch after the first treatment.
You should get some Kaytee baby bird food or some canned cat...