First time duck owner here, I have 3 ducklings who've been healthy so far until 3 days ago when one of them stopped eating and started acting very lethargic. As of this morning, she's constantly panting, even though she's in a cool area. She is drinking and pooping, her poop is mainly liquid but has recently been white. I don't know what to do and I'm starting to worry. Is there anything I can do without taking her to a vet? 
