One of the ranches I guided on had Rheas. After the exotic bird will make you millions bust, they wanted them eliminated. The ones we shot ALL had some sort of worms, almost like tapeworms, and nobody would eat them. If you can drain the eggs, they are cool when decorated like Easter eggs.
I would shoot them with a Rossi .357 mag, lever gun using 125 grain semi jacket hollow points. When hit it would look like a pillow exploded. Sometimes it would take two hits to put them down for good though.