Dogs convey their emotions and thoughts in a lot of different ways. They're communicating with us, but we're not always sure what they're trying to say. Whale eye is an example of dog communication. It's dog body language that gives you and other animals a clue as to what the dog is feeling and thinking.
What's whale eye?
"Whale eye" is a term dog trainers use to describe a dog's body language when the whites of his eyes—the sclera—are visible. The dog will avert his head slightly, but his eyes stay fixed on something or someone. The whites of his eyes will appear in a half-moon shape, usually at either the inner or outer side of the eye, but sometimes all around. Whale eye is sometimes called half-moon eye.
Whale eye isn't always easy to detect in all dogs. The eyes of dogs with short noses always show a bit of white. If the dog isn't showing any other signs of agitation, what you're seeing may not be whale eye.
Signals that May Appear With Whale Eye
A dog that's exhibiting whale eye might throw off some other body signals as well. Is his hair standing up along his spine? Raising his hackles is not a good sign. He might also growl a warning or freeze in place as if he's ready for anything.
What Whale Eye Means
If you notice that a dog is exhibiting whale eye, he's telling you that he feels anxious and uncomfortable about something. He's stressed. Whale eye can be a sign that the dog will soon become aggressive because a dog who is anxious is more likely to bite. If you notice this type of dog body language as you're approaching a dog, then back off until he relaxes and becomes more comfortable, or at least until you can figure out what's going on.
Take stock of his surroundings without approaching him. Is there another dog or cat in the vicinity? Is a stranger approaching? He may hear something that your ears aren't fine-tuned enough to pick up on yet, like footsteps outside approaching your door. Your child may be reaching for his favorite toy—or worse, his treat. It might be that he doesn't like what you're doing, like ruffling his ears.
What to Do
Your dog is hoping you notice his eyes. He wants you to do something to fix whatever is wrong, so this is always your best course of action if you can identify the problem. If it's something you're doing, stop. If another dog is approaching him in a public park, lead him away, keeping in mind that he may also be stiff as a board so you might have to coax him to move. Scolding him is useless and will probably hurt his feelings. How would you feel if you tried to whisper something urgent in someone's ear only to be rebuked? When your dog exhibits whale eye, the problem isn't with him but is usually something external.