My turtle has white foam by its mouth, on and off, and while hibernating wakes to gape—is it gastroenteritis?

Turtle gastroenteritis shows low spirits, slow response, vomiting, soft or loose stool, often from cold feeding, temperature swings, bad water or spoiled food. If your turtle has those signs it may be gastroenteritis. But gaping and foam may instead be pneumonia; if it floats tilted in deep water, gapes at the surface with sound, has blocked nostrils or fears water, it is likely pneumonia linked to hibernation temperature swings.

Control the temperature at about 28°C and soak in penicillin or streptomycin.