Hidden signs a dog might bite

Written by Dr Dennis Wormald,
Last updated June, 2022

Working as a GP vet, you see aggressive dogs on a daily basis. Many dogs are easy to read, clearly displaying their intention to bite. Other dogs seem to bite without warning. After a bite incident or near miss, most vets would be a little more cautious around dogs for a while. Some vets regain their confidence, others don’t. Some vets remain fearful of any dog that could be aggressive, for their entire careers. Being fearful of aggressive dogs isn’t a bad thing, it does help us keep our fingers after all! However, there is a way to both gain confidence and reduce your fear of dogs at once. The trick is to get really good at reading dogs.

Why dogs bite
Dogs don’t just bite people for fun. Well, actually they do. Some dogs play-bite, but those are the exception at a vet clinic! Most dogs in the vet clinic bite because they are fearful or in pain (or both). The more fearful or painful the dog is feeling, the more strength they will tend to put into their bite (and the more injured you will be). A good general rule of thumb to remember is this: most fearful dogs will not bite, but most dogs that bite are fearful. Even more importantly, almost all bites that seriously injure are done by dogs that are very fearful or painful. Most vets are pretty good at detecting pain in dogs, and not bad at detecting fear either. The problem is that being “not bad” at detecting fear in dogs is like being “not bad” at crossing the road in traffic. You will probably be fine most of the time but sooner or later you are going to get hurt!

How to detect fear in dogs
There are a lot of signs of fear in dogs that most vets will pick up pretty easily. You have probably noticed them before, including in the dogs that show aggression. Signs of fear in dogs include withdrawing/hiding, cowering, trembling, looking away, whale eyes (angled gaze), dilated pupils and even barking, growling and biting. These are things that you should practise looking for in all dogs. However, to really improve, you need to look for these things in dogs while they are acting aggressively too. If a dog has a muzzle warning on its file, or the owner brings the dog in muzzled, think of it as a learning opportunity! While you are working with the dog, try to find as many signs of fear as you can. Keep in mind that a fearful dog will sometimes only give you one clue that they are fearful. In particular, try to look out for the one hidden sign of fear aggression that most vets find hardest. This is the freezing behavior. Their body goes stiff, their muscles tense, but they just stand there or sit there not moving. Some dogs appear friendly and non-fearful when you first meet them, but then as soon as you start touching them they freeze. You might try to move their head to look at their teeth, and find that they are resisting you with all their force. These dogs are ready to snap, and they bite hard once they do.

Dealing with the most dangerous cases
For most vets, the really dangerous cases are the dogs that are aggressive without warning and the owner doesn’t say anything. In this situation, the vet would move in to examine a dog, the owner would know it might bite but not say anything, and the vet touches the dog which then looks around and bites their hand. A range of things have gone wrong in this situation, but the situation isn’t hopeless. These dogs often exist because their growl and bark has been punished out of them. The owner has yelled or smacked the dog every time it growled at a person. The dog has learned that growling or barking are no longer an option. This means the vet has no warning before the dog bites unless they know how to read fear in a dog. The good news is that the dog will still be displaying signs of fear, even if it’s just the hidden sign of freezing.

The strange things that happen when you start using these tricks
Once you become good at reading the hidden signs that a dog might bite, you notice strange things start to happen. Firstly, every so often you will hear people say “oh it’s okay, he doesn’t bite” when you are interacting with their fearful dog. This is because without realizing it, you have noticed the dog is fearful and are treating it as though it might bite! The dog will really appreciate this, because they may be used to people overstepping their boundaries of what they are comfortable with. When you start interacting with the dog and it can sense that you don’t push past what they are comfortable with, they start to really trust you. This can take a few visits for dogs that have been Traumatized by past vets, but it’s really rewarding when it happens. Another strange effect is that you start realizing how fast the signs of fear can come and go within one dog. You might start doing something, notice a subtle sign that they are fearful, stop, then the dog relaxes, then you try again and they show the sign again. This is when you are dancing on the border of what the dog can tolerate happily. When you get really confident (after years of trying), you will be muzzling dogs that the owner says don’t bite, yet examining other dogs without a muzzle that have a large caution warning on the file! This is because you will be able to trust your own eyes more than what anyone else tells you.