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Canine Behavior/Possessive/Agressive Behavior


My male (neutered) Australian Shepherd who is 1 year, 5 months old LOVES to steal things that aren't his like clothing, paper, anything that can fit into his mouth. Sometimes he will allow me to take out what is in his mouth and other times he will not open his mouth and when I try to open it he growls, lifts his upper lip and his pupils dilate.

My mother told me when he steals something he will allow her to open his mouth to retrieve the object and has only growled at her once. But with me he every time growls, lifts his upper lip, and does try to bite me sometimes when I go to retrieve the item…

I always try to assert my dominance with him and be the alpha dog, though with him it can be tough sometimes but I keep at it. Luke does like to steal our food too as well. When he gets close to my food I stare at him and tell him "No!". When that doesn't work I do make a growling noise and it does work usually and he backs off. I have no idea if this little bit of information will help….

He's started this growling when he gets something for a few months now, but today he did nick me on the hand. This is his only aggressive/possessive behavior and I really don't want anything bad to happen to myself or anyone else. I hope you can help me.

Many thanks!

Thank you for your question. The behavior you're describing is called Resource Guarding. It's a fear-based behavior. When the dog has something he feels is a prized possession and he feels threatened, or that he may lose his possession, he is compelled to guard it by giving distance increasing signals. These signals may include freezing in position over the item or with the item in his mouth, hard stare at the perceived threat (in this case you), growling, snarling, air snaps and escalating to biting as you're now seeing.

Unfortunately, the confrontational approach you've been using is actually making the problem worse - as you're seeing in that he continues to do it to you and his overt aggressive display is escalating with you to the point that he has now made physical contact.

Rest assured, there is a fairly easy fix for resource guarding. It's a bit counter intuitive because when our dogs growl, our instinct is to scold, punish or otherwise make it clear that we don't like that behavior. When dealing with resource guarding we actually want to do the opposite. We want to reassure the dog that we are not a threat and he has no reason to fear our being near him with something he feels is valuable. Not only do we want him to feel safe and secure with us being near him, we want him to feel comfortable with us asking to see things he finds valuable.

So to do this, we need to set him up with things he likes (such as his dinner bowl) and then do exercises that help him learn that our movement past him and then nearer to him and then interacting with him are all very good things. We do this most easily by using an exercise referred to as "pass by's". Essentially, you stay far enough away that while he is aware of you, he is not feeling overly concerned. He's not freezing or speeding up his eating or staring at you or growling or any other protective behaviors. As you walk past at this distance, while he's eating his regular kibble, you are going to toss something extra special such as chicken breast or string cheese into his bowl (or as close to it as you can get from your distance). He'll almost certainly stop eating the dog food long enough to get the goodie. So you toss the goodie and keep walking past/away. Then wait 10-60 seconds and walk past again and again toss a goodie. You'll repeat this exercise at this distance until he is eagerly anticipating your approach at that distance. You'll see a behavior change that is clear. Instead of ignoring you or any subtle guarding, he's likely to stop eating from the bowl and look at you with happy anticipation. He may even step away from the bowl toward you or sit politely as he waits for the goodie.

When he's doing that at the first distance, then you'll continue the exercise a bit closer - perhaps a foot or two, perhaps just 4-6 inches (he will tell you when you've come close enough). Then continue the exercise at the new distance until he is eagerly anticipating your approach at this new distance. Continue like this until you can walk up to the bowl, drop a goodie and walk away.

Then, when he's comfortable at that proximity, you'll begin working on the detail work. Hold out one hand, drop a goodie with the other then take both hands away. Repeat until holding out your hand (well above him and not directly reaching for his bowl) is generating happy anticipation. Then reach toward, but do not touch the bowl. SAFETY FIRST. WHEN YOU ARE FIRST REACHING FOR THE BOWL YOU SHOULD INCREASE YOUR DISTANCE SO THAT YOU CAN'T ACTUALLY REACH IT. YOU'RE WORKING ON THE GESTURE AND YOU WANT TO MAKE SURE YOU'RE NOT IN DIRECT LINE OF CONTACT IF HE MAY GET UPSET BY THIS EXERCISE. Build up to being able to just touch the bowl with one hand while dropping a treat into the bowl with the other.

Then, you can start working on putting the treat in and mixing the kibble around a little. This is a goal behavior. Take your time to get there. Let him tell you when he's ready for each next step. If you move too close too quickly and he begins to show resource guarding behaviors, simply back up and work at a further distance a bit longer until he's very clearly happy with you at that distance and then reduce the distance more slowly and methodically. If he was fine with you at 4 feet from the bowl, but when you went to 2 feet he got upset, go back to 4 feet away for several trials. Then ease up to just 3feet 8inchs (just 4 inches closer), then 3ft 4 inches and so on.

There's an excellent book that will walk you through this process. It's called Mine! A Practical Guide to Resource Guarding in Dogs by Jean Donaldson. She explains what resource guarding is and provides a more thorough step-by-step plan to work through it than I can provide here.

The other half of this is teaching him a Drop command. We do this by making trades with him. When he has something, rather than chasing him down or trying to pry it out of his mouth, get something he likes even better (this may be another toy, the offer of going for a walk or some food like cheese or chicken or hotdog). Tell him "Drop" in a friendly, inviting tone. Count to 2 (1 one-thousand, 2 one-thousand), then show him the toy/leash/food lure. If it's a toy, you may need to squeak it or tease him. If it's food, you may need to hold it just in front of his nose about 1 inch away so he can't help but smell it. If it's his leash and he's not immediately interested, then this may not be the right trade offer.

Once he drops the item he has, take it away at the same time that you offer him the trade (throw the toy, start a tug or give him the food).

By telling him Drop and pausing for 2 seconds, we are giving him a chance on every single trial to tell us if he understands the command. If he understands, he will put down the item. If he doesn't, then we help him succeed by luring the behavior. And by not bringing the lure into view until after that 2-second pause, we avoid the process of bribing him. A bribe would be holding the treat to his nose before asking him to drop as this is promising him the tasty treat first. Asking him to do a behavior and then helping him succeed sets him up to do the behavior before the reward appears. This means that he has to act on his environment first - he has to perform without the direct promise of reward, but only for the hope of reward.

The first time he drops the item without seeing the lure first - make the reward a jackpot. Huge, happy praise and instead of just 1 treat, make it 8-10 treats given one at a time in quick succession. Make it a party! This will really drive home that dropping items when there is no reward in sight, brings out the lottery win. At that point, you can then begin rewarding only his best performances. In other words, when he drops items on request, without a lure/prompt, he gets big praise and treats or games or other toys. But, if he needs help and you have to lure/prompt him to drop the item, then he just gets a "thank you. Let's try that again."

NOTE: You should be setting up training sessions where you are able to practice asking for Drop 8-15 times in a short period of about 2 minutes. Do  this with a toy or chew that he likes but isn't actively guarding. If he's actively guarding, then do the pass-by exercise first so that you can handle the item with him. I often do this exercise with a Bully Stick.

In the beginning you may need to keep your hand on the item so he can't run away. ONLY DO THAT IF HE'S NOT LIKELY TO BITE YOU FOR KEEPING HOLD. If you are trying to lure/prompt the behavior and he's just not letting go, you can take hold (if it's safe) of the object. But do NOT try to pry it out of his mouth. Instead, continue to lure him and wait him out. As he shifts his bite/grip - which he will - you can slowly work it out of his mouth. When you finally get it, give him a jackpot so that he can see that it's really worthwhile to him to allow you to have these things.

When practicing trades, you will give the item back to him. This way he's learning that letting you see his things means he gets an extra special yummy AND he gets his item back. This way when you really need him to drop something, he'll be more likely to work with you. Just be sure you replace the prohibited item with something he is allowed to have.

If he has a propensity for stealing paper, then use old paper you were throwing away and practice trades with it. If he destroys it or eats it, you're not worried because it's not a bill or tax papers. But it allows you to practice with the same type of material so that he's used to the experience with you.

Mine! A Practical Guide to Resource Guarding

A video of me practicing Drop with my puppy. Notice that my timing is actually off in the video - I'm presenting the treat nearly simultaneous to asking for the drop (essentially bribing him). That was an error in the training that day. But you can see how the process works and you can see how I handle it when he fails to let go - when he begins to resource guard by freezing, pulling away and trying to flee the scene with his Bully Stick. After I work through that moment of resource guarding, I keep a hold of the Bully Stick for the next 2 trials until he relaxes and I'm confident he's not going to try to run off again. But, I also know that this dog won't actually bite me. So you need to assess your dog to determine if it's safe to do that. If not, then you'll need to do work with a less valuable item to start and/or do some pass-by exercises with the objects he is more protective of

I hope this proves helpful. As always, if you feel uncomfortable implementing this protocol on your own, you should seek some assitance from a local professional who uses force-free techniques such as described here so that we don't further escalate your dog's fears and concerns.

Good luck. Pleae feel free to followup if I can be of any further assistance.

Los Angeles Behaviorist  

Canine Behavior

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Jody Epstein, MS, CPDT-KA


IF YOU BELIEVE YOUR DOG IS ILL OR INJURED, PLEASE CONTACT YOUR LOCAL VETERINARIAN IMMEDIATELY. THIS IS NOT THE FORUM TO ADDRESS URGENT MEDICAL ISSUES. I AM NOT A LICENSED VET AND HAVE NO DIAGNOSTIC SKILLS. ***I have been answering questions on All Experts for over 8 years now. I enjoy being able to offer assistance in this forum. I do need to be clear, though. If you’re looking for free advice about a specific behavior question, you MUST submit your question to me via All Experts. If you bypass All Experts and write to me directly through my website, I will ask you to submit via All Experts. On the flip side, if you’re local to Los Angeles and you wish to speak to me privately about an in person consultation, please go through my website. I appreciate your assistance in keeping my volunteer work on the volunteer site.*** I can answer questions about the following canine behavior issues: obedience, timid/fearful & fear-based aggression, nuisance behaviors, families that are expanding with either new human or new animal members and many other issues. If you have potty training questions please first read my trio of blogs at If you still have questions after reading the blogs you can post your specific questions here. PLEASE be as specific as possible when asking a question. Give me a detailed example of the situation - dog's behavior, body language, circumstances surrounding the issue, what the consequences are (another dog's response, your response), etc. I can only provide insight if I can get a picture of the whole scenario. If I ask for further details, please provide them. In person I would normally observe for at least 90 minutes to assess the situation and the dynamics before offering tools and suggestions to modify it. In writing it is ever so much more difficult. Thank you for your participation in the process.


I have been a professional obedience trainer for 9 years, and specializing in behavior modification for 8 years. I have owned dogs my entire life. I own my own dog training and behavior modification business called Nutz About Mutz.

I am a Certified Profession Dog Trainer - Knowledge Assessed (CPDT-KA), #2133301 ; I am a member in good standing with the Association of Professional Dog Trainers (APDT), #77763 ; I am an AKC certified Canine Good Citizen evaluator (CGC), #71253

Publications ; ; Multiple articles in the local pet magazine Pet Press (found across Southern California)

I have a masters degree (MS) in Animals and Public Policy, with a minor in Animal Behavior, from Tufts Cummings School of Veterinary Medicine. I also have 3 years of graduate education in Animal Behavior and Learning from UM-Missoula and UL-Lafayette. I continue to educate myself to canine-specific behavior through extensive reading, online interactive workshops, vidoes and attending canine behavior conferences, workshops and seminars. Beginning in March, 2017, I will be the Behavior & Training Manager at Second Chance Center for Animals in Flagstaff, AZ.

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