Trying to take food or toy away from him. NEVER bother a dog while he is eating. The most common situation when a dog bite occurs is while a dog is eating. Dogs have an innate instinct to protect their food.
Playing "tug of war" with a dog. Many dogs interpret this as aggression. If they "win," they feel empowered. If they feel threatened, they may try to retaliate.
"Surprising" a dog. (sneaking up on him or startling him while he is sleeping). Often, the dog's defense mechanism will kick in, and he will bite in self-defense.
"Rough housing" with or other sudden movements toward the dog's owner. Many dogs will see this as an attack on their owner, and will attack you to defend the owner.
Ignoring their warning! If a dogs barks ferociously or growls when you approach his territory, bed, etc. and you continue, that is an engraved invitation to get bitten. They are warning you that they don't like that and stop. Listen!
Inappropriate touching. Dogs generally don't like their ears, tail and feet tugged. Some don't like being inverted and rubbed on their belly. This is a position of submission and an aggressive dog will resist this "challenge" vigorously.
The Proper Way to Approach an Unfamiliar Dog:
First, get the "okay" from the owner.
Hold out your hand, fingers closed, palm down, slowly toward the dog. Allow the dog to approach your hand and sniff it.
Wait for the dog's "okay". If he wants your affection, he will lower his head, perk ears, or even come closer to you. If the dog puts his ears back, flat on his head, or growls, or cowers, don't pet him.
Pat the dog on the top of his head, or along his back. Avoid touching his belly, tail, ears, or feet.
What To Do If You Encounter a Seemingly Aggressive Dog:
Stand still. If you keep approaching, the dog will interpret this as an attack.
Don't make eye contact. This is a challenge to the dog.
Don't smile. The dog thinks you are "baring your teeth" at him. This is an invitation to fight.
Wait for the dog's owner to come and restrain the dog.
Respect the dog's wishes. If the dog is barking and growling, he is expressing his definite displeasure with your actions.
What To Do If You Are Attacked by a Dog:
Don't move! You cannot outrun a dog, no matter how fast you are. Running only provokes an angry dog.
Look away. Staring an aggressive dog in the eyes is a challenge.
Use a soft, soothing tone of voice. Loud, angry-sounding words and screaming only spur on the dog.
Keep your arms to your side, with your fingers curled in so the dog can't bite them.
If he bites you, DO NOT PULL AWAY. This only spurs the dog on. Remain calm. Try to ram a stick, or other readily available object down the dog's throat to make him gag and until it lets you go. Don't hit the dog. Again, that just makes the situation worse.
If you are on the ground, curl into a fetal position. Cover your head and neck. Lay perfectly still. Usually a still target is boring to the dog and they will retreat.