Do animals drown in Minecraft?

Solution 1:

Animals can drown.

They follow the same rules as everything else (except for slimes and endermen) and float in water. If you have an air block above the level of the water then they should be able to breathe just fine.

Solution 2:

Mobs do different things in water:

• Most mobs will drown if their head is underwater, exactly like the player. Slimes will drown.
• Squid will not drown (!) but will suffocate when not in water.
• Endermen will immediately teleport if exposed to water, so cannot drown.
• Blazes are damanged by all contact with water, so I'm not sure if they can drown because they'll die from water exposure first anyway.