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Canine Behavior/Sudden fear/aggression towards family


Hello - I have a 2 yr old intact male dog that was born & raised in our home.  He was well socialized, went to puppy kindergarten, dog training, dog shows, multiple obedience focus classes, etc.  He has been great with kids his whole life, good with 98% of the dogs he meets - male or female.  

He had a brief fear period when he was about 6 months old right after a bad experience at the vet for his rabies shot and exam.  He was worried about people touching his rear and would jump away and occasionally growl.  We worked through that relatively quickly and he has been wonderful until just about 4 months ago.  He suddenly started growling at my kids when they would approach him.  Then he started growling at me in the morning when I would wake him up to go outside.  He stiffens up, hackles come up on his back, glassy eyes, in a trance.  Growling gets worse if I try to touch him.  I have tried avoiding eye contact, tossing treats at him, giving him time to wake up before I go in the room, etc and it's better the least interaction I have with him until he goes outside to potty and eats.  Sometimes he will growl when I am putting his bowl down or entering his indoor/outdoor dog run where he spends the day when I am at work.  His episodes are the worst in the morning, but can happen at any time. They seem to be worse when he is by himself.  If he is with another dog, he seems more relaxed.

I have an appt scheduled with a veterinary behaviorist, but it's another 7 weeks before our appt and I am hoping to at least get some training tips for some type of progress with him before that.  He has not tried to bite yet but I don't want to put my kids at risk and with as horrible as he sounds sometimes, I'm not sure I would rule the possibility out!

I did test his thyroid twice with Jean Dodds (6 months apart) and he was normal both times.  Even tried a low dose supplement as there is some thyroid trouble in his pedigree, but haven't seen much change in his behavior.

I have no idea why this started.  He doesn't get along with his sire, but he is pretty old now and they don't ever have to directly interact. They don't fence fight - just don't get along well enough to run around together.  His behavior all seems fear-based but I know of NOTHING the kids have EVER done to him and I have been his trainer with clicker, treats, positive reinforcement, etc.  He's never been a dog that needed heavy corrections for anything.  He is the smartest dog I've ever had and when he is feeling normal, is the best dog ever.  Is there any hope he can be fully rehabilitated?  Will I always have to worry about him around my kids?  :-(  Thanks in advance for any insight.

First off, I just want to say that you are an amazing dog parent! Starting off from the beginning with positive reinforcement training, setting him up for success, testing his thyroid with the "big guns" tests and repeating it, and already have an appointment with a vet behaviorist (all of which were going to be recommendations from me!).

Now, to your issue. I'm sorry that you're having issues with what you describe to be fear-based aggression. You didn't mention his breed, but sometimes that can play a role in such issues.

The first thing to know is that we do not want to punish or correct the growl. The growl is his most obvious way to communicate and so it's important that we acknowledge the communication and adjust our part of the interaction to help him feel safer. If we correct the communication, then he may stop telling you he's uncomfortable and that is when the "out of the blue" bite is likely to occur.

Because there are children involved in the home environment, it becomes significantly more difficult to address this issue in this forum. Since you are already scheduled to see a vet behaviorist, I will not try to offer diagnosis possibilities beyond pointing out that the issue may be medical in nature - especially since it's a rather sudden onset behavior change.

Is there any chance he's in pain somewhere? Joints, paws, belly, etc? Pain can cause a lot of fear-aggression responses.

What I can offer you here is recommendation for management until his formal evaluation with the veterinary behaviorist. You didn't indicate the age of your children, but I would encourage you to make sure that the children do not approach or try to initiate interaction with the dog - most especially at meal times or when he's resting. If he approaches the kids for play or love, that is likely to be OK, but you should be physically present and observing and ready to intervene at the first sign that your dog is showing signs of fear or anxiety (see below for some common signals of fear and anxiety).

Further, I have personal experience with a dog who had what I describe as Cujo moments if you woke her unexpectedly. If I entered the room, moving directly toward her, my dog would come out of sleep launching at the person approaching - all teeth and snarls and barks and growls. Her eyes were glassy and she was not initially responsive if you tried to speak to her. I would make sure I was safe, but could literally watch her eyes clear and her whole demeanor change as she become more fully awake and registered that it was me near her and not a threat. In her case, if I stood across the room from her and said her name in a soft, cheerful voice and waited for her to wake up and look me in the eye, and I could see that she registered it was me, then I was able to come into the room without fear of her Cujo moments. I was able to work this routine sufficiently that all I had to do was pause at the doorway, say her name and tell her that I was coming in. She never once Cujo'd at me if I just took 2 seconds to let her know it was me coming in.

I do not encourage your children to try this. But you may try it and see if it makes a difference. It may be a manifestation of the old saying "let sleeping dogs lie." Or it may be related to the overall behavior change.

Anxiety/stress behaviors include:
licking lips, licking nose, blinking repeatedly/squinting, panting when he's not just been running around and it's not overly hot, drooling, dilated pupils, ears pulled back, front paw raised (this is an appeasement signal that indicates uncertainty and I sometimes translate it as a "please" such as "please may I?" or "please don't.", rounded back, tail tucked, head lowered, averting gaze (avoiding looking directly at you), yawning when he's not tired (indicates conflict and uncertainty).

These signals generally don't happen individually. Be sure to look at the snapshot of the whole dog. If you see one behavior, you'll likely see several others.

The Living with Kids and Dogs websites has some nice pictures and videos (with description) of the stress signals the dogs are giving.

Dr. Sophia Yin's website as several great posters that have drawings of various stress signals. You can download them for free and print them out on regular paper and then help your kids learn to recognize each of the behaviors and discuss how the kids should respond if/when the dog shows these signals (increase distance / disengage to help the dog feel safer).

Canine Body Language (you'll need to provide some basic info in order to download it, but you will not be inundated with emails or anything)

How Kids Should and Should NOT Interact with dogs (2 posters)

How to Correctly Greet a Dog

You'll probably need to provide the basic YOU info for each poster in order to access the download. I recall having to do that, but I've never gotten any unsolicited emails or anything from doing that.

I recommend to every single one of my clients to read the book On Talking Terms with Dogs - Calming Signals , by Turid Rugaas. This book will describe all of the above stress signals as well as several others - providing a description of the behavior as well as context, what it means, how other dogs typically respond when they see a dog giving that signal and how we can respond in a way to help the dog feel safer. It's a great book and will open up a whole new conversation between you and every dog you encounter.

I'm sorry I can't offer much more than this, but given the risks with children and that this is a new and sudden behavior change, it really is most advisable to have the formal evaluation by the vet behaviorist.

Please do update (via the reply button) after your evaluation and let me know what the vet behaviorist thinks is going on and what they suggest. And let me know if I can be of any other assistance.

Worcester, MA Behavior Specialist
Masters Candidate - Animals and Public Policy (Animal Behavior)
Tufts Cummings School of Veterinary Medicine

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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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