-- Some rabbits can have heart attacks if they get extremely scared. A breeder we know lost one of her rabbits during a thunderstorm due to the loud noise. Someone who purchased a rabbit from us lost rabbit to heart attack when their dog ran up to the rabbit for the first time. This is extremely rare though. We expose our babies to our dog, and other loud normal noises from a young age. By the time they are weaned they never even flinch!