Are you seeing any bubbles in & around his mouth? Usually when they're just hissing, you won't see bubbling (unless they just happened to drink water?).
Any open-mouth breathing? Holding head up to breath? Had a look inside his mouth lately? How's the appetite? (his, not yours, lol)
And why, if his heat source is thermostat controlled, would the outside temperature fluctuations cause much of an issue indoors so as to weaken his immune system?
Reply With Quote