Because a dog's vestibular system is located within the inner ear, a vestibular event affects a dog's balance and therefore can lead to dizziness. ... Dogs often lean to one side as well as walk around in circles when their vestibular system is affected.

Another scenario is when he refuses to be moved from a bed. Let's say the dog has always slept on the bed with its owner. Then, one day, the owner decides the dog must sleep somewhere else. The dog therefore, upon being moved, growls at the owner, who is surprised and frightened, so he backs away. The growling behavior has now been reinforced, and the dog will use it more frequently to show its power.

Dogs may drool around other dogs because they are excited or anxious.