What are the causes of aggression in dogs?

One of the more serious problems dog owners face on a regular basis is aggression. This can vary from breed to breed, with some breeds being naturally more aggressive and others more passive. There are also a variety of different reasons that could be causing it, and they often vary depending on who the target is - people, other dogs, cats, etc. Some of the core reasons and what you should do to stop the aggression are as follows.


General Flea Tipsheet

pictures of fleas

flea bites

Pet Questions

Pet Product Reviews



One of the more difficult problems to correct in dogs is fear aggression, because it can be caused by shyness or other emotional issues that cause the dog to be inherently more fearful. When caused by fear, the anger is usually directed towards strangers - it can be against both humans and other animals. It most often happens in the dog's home, because there is no place for the dog to retreat to and because it is on its "territory" and will view the newcomer as an invader.

For some dogs, this is simply untreatable. It can be caused by both genetic factors and by abuse of the dog, and if either of these is too severe you may never get the dog to behave normally. However, there are a couple of different ways to train your dog not to be afraid of strangers, which will reduce its aggressive behavior towards them.

With aggression towards people,  the first tactic you should try is to acclimate your dog - just take your dog out to meet a bunch of people it doesn't know. Do this OUTSIDE the home, and preferably at first with people that you know but the dog is unfamiliar with. This allows you to control the encounters, and to make sure the dog isn't being mobbed with people. Neighbors can be great for this. Take your dog on regular walks, and before you go out, walk over to a different neighbor's home each day and ask if they would meet the dog, pet it, and give it a treat. Try with adults first, and once your dog has gotten used to meeting new people, you should add in kids to make sure that it will stay well behaved with children as well.

After the dog has met 5-10 people one-on-one, you should take it on walks through popular areas where it will come across other people. Parks are great for this, as are sidewalks where joggers frequent.

You should also control your own emotional reactions to the stranger. This can be a prime cause of fear aggression - you begin to worry about what the dog will do, so you don't greet the person as a friend, you act afraid yourself - not of the person but of the dog. Your dog doesn't understand this, but it can tell that you're afraid - and it thinks you're afraid of the stranger, too. You should be firm, in control of the situation, and obviously friendly to the person you're meeting.

If that doesn't work, you may have to try tactic two - dominate your dog. Dogs generally defer to the alpha dog, so if you establish dominance over your dog, it will be more likely to do what it thinks you want instead of using aggression to get its way. In addition to the suggestions on that page, you should be firmly telling your dog "NO" and "BAD DOG" when it growls or is aggressive towards a stranger. Do not take the dog away if it is aggressive to a stranger - force it to sit and deal with the situation. If you are always removing your dog to another room when it's aggressive, it will learn very quickly that this is a good way to get rid of the stranger.

Aggression in Protecting Possessions

A dog may also be aggressive when it sees someone else or another dog interfering with its toys, its bed, or its food bowls. This form is often related to the dog refusing to acknowledge you as dominant. It can also be an ingrained behavior that is hereditary - much like children who run around claiming that every toy is theirs.

Because it can be dangerous to try to remove items from a dog that is biting to protect them, you need to train your dog in basic commands first before trying to get rid of this behavior. Also, switch any toys or bones to the longest possible ones you can find. This will make it easier for you to take them from the dog's mouth without risking a bite.

Once your dog learns the basic commands, you should remove all the dog's toys. Stop leaving them out - only take them out during periods when you want to play with the dog. You should play with one toy at a time, and you should rotate toys during play. Teach your dog commands to "pick up" the toy and "drop" the toy. The basic idea is that you want the dog to learn that if it lets you have the toy, it is not always going to stop the play session - most of the time, it will result in you giving it a different toy. This will result in less aggression - the dog will get less defensive about you taking things from it because it thinks there's a chance you will give it back.

I used to take my cats out to wander around in the backyard playing and had to train them using something similar because they would run away any time I tried to bring them back in. By picking them up periodically, carrying them somewhere else in the yard, and putting them down, they stopped running away because 90% of the time I picked them up I wasn't taking them inside. You want the same notion in the dog's head - most of the time you take a toy from it, you are going to be giving it a new toy. You can even just give the dog back the same one - but it has to start thinking that it's not going to "lose" the toy by giving it to you.

Some dogs are aggressive towards people specifically in defending their food. For this kind of aggression, you should take away the dog's food bowl and feed it by hand. For a week or so, have no food bowl down at all - fill it up with the amount of kibble the dog would normally eat in a day, and feed the dog a few kibbles from your hand every once in awhile. Make sure the dog gets a full meal (empty the bowl), but make sure it eats everything straight from you. After you've done this awhile, put the bowl back but leave it empty. Instead of handfeeding the dog, put the kibble into the bowl and let the dog eat it. It will soon come to learn that when you go to its bowl, you are giving the dog food and not taking it away. You should be able to switch back to leaving out kibble after awhile, but you should also periodically go up to the dog while it is eating and put a treat in the bowl. This is to reinforce to the dog to learn that it is a GOOD thing for you to go near its food.

If the dog is aggressive towards other animals in your house when eating, you need to do something different. One option is separate bowls. Keep them far enough away that each dog can eat at a different one, and keep them both filled. If you've got cats, then put the cat food up on a counter or somewhere the cats can get to but the dog can't. You should put down a separate bowl with a small amount of cat food in it and train your dog not to eat from it - scold the dog and use your standard punishment when the dog tries to eat the cat's food.  

Back to Pet Questions Page

Back to Flea Control Guide Main Page

Text copyright 2005-2006 Fleascontrol.com and may not be reproduced without consent. This is not the official web page of any of the products listed on this site, this is a review page created by an individual. It is not by a vet, and is meant to be informative and not to substitute for a vet's advice - always consult a vet if you suspect a health problem.