We had just gotten 4 ducklings a couple months ago, we think their about 4 months old. Our pekin is very sick and tired. He tries to stay with the other 3 ducks but can't keep up with them because of his leg, He kind of just beaches himself on the side of the pond. His beak is very warm, he doesn't eat like he use to. He trembles and shakes every once and a while. He's droopy and doesn't seem to have high awareness. We've given him Tetracycline Hydrochloride and Electrolytes to hopefully help any pain he's in and/or fever. A vet is out of the question due to the high expenses. We really don't want to lose him because we just got him and he's so young. He's now sleeping with his head down instead of behind his wing. Someone please help!