My brother owns a black lab (Scout) who's a year and five months old now. I helped raise this dog from a tiny puppy and spent a lot of time with him while he grew up. Last fall, I cut my hair from mid-back to dramatically short around my ears and went off to college. Every time I'd come back to visit, Scout would run up and lean on my legs as a signal that he wanted to be petted. This was normal, however, he would also growl at me at the same time. It wasn't the playful growl, either. This was a very angry growl and it disturbed me, yet he still wanted my attention so I was left confused.
Yesterday I moved back home from college and my brother and Scout were visiting in the house before they left. I'd given Scout some snacks and the four of us - my mom included - stood at the door to say farewell for the night. Scout was leaning on my legs and I was petting him when he abruptly went berserk and attacked my arm. Thankfully, my brother called him off (and he listened) before he broke the skin. But I'm left wondering why the sweet dog that I knew suddenly wants to aggressively injure me. He hurt my feelings a lot more than he hurt me physically. Any ideas for his sudden change in behavior and how to revert it? My brother doesn't want to have to get rid of his dog. Also worth noting - Scout has never acted aggressive or attacked even a complete stranger, yet he attacked one of the people who raised him. I get the feeling he doesn't like my short hair, but this has gone much too far.
Any and every suggestion will be completely appreciated. Please give me your input.

I would strongly recommend that you seek professional help for this dog as soon as possible.

I live in Florida, so I cannot make recommendations. However, I am using a certified trainer for my dog, and it is making a world of difference. As a start, perhaps you could look in the yellow pages for certified dog trainers. You may also want to consult your veterinarian, just to make sure that there are no undiagnosed medical conditions.

I hope that you can get help for your dog before this aggression escalates and he injures someone outside the family. If that were to happen, you would be left with very few options. Animal aggression is a very serious problem which should not be left to get worse.

Good luck!

Thank you very much. I hope that it won't come to getting rid of or putting the dog down. It would really upset our family, since up to this incident he has been a very intelligent, obedient, and sweet dog.

Hi Cloud, I was thinking about your situation, and I got you a list of certified trainers who may be able to help you. Here is the OHIO list:


Ohio
Name: North Coast Dogs
Contact: Michael Baugh
Address: 14819 Madison Ave.
Lakewood, Ohio, USA
Phone: 216-221-3647
Email: michael@northcoastdogs.com
Specializations: Nonviolent reward-based classes and in-home consultations. We accept aggression cases including a limited number of bite cases.

Name: Pawsitive Pet Solutions, LLC
Contact: Joann Hughes
Address: 3747 Winthrop Drive
Beavercreek, Ohio, USA
Phone: 937-572-3436
Email: pawsitiveps@cs.com
Specializations: Puppy, Beginner & Intermediate Clicker; Private Training; Behavior Modification for cats and dogs. Rover Recess; Agility



Name: A Better Pet LLC
Contact: Rachel Friedman, MSW, LISW
Address: 2553 Queenston Rd.
Cleveland Heights, Ohio, USA
Phone: 216) 321-7654
Email: Rachel@abetterpet.com
Specializations: A Better Pet LLC specializes in positive reinforcement pet and service dog training. We use clicker training with a holistic focus on helping people understand how to communicate effectively with their canines without force. We also have retail products available. Private in-home and group classes. We also work with aggression cases.

Hi! For those of you across the USA who may need dog trainers, either today, (or next year!), here is a site which will provide you with details of trainers in your area:


http://www.courteouscanine.com/referral.shtml

The right trainer can make a world of difference!

Good luck.

I have seen this happenning a couple of times. My cousins girl friend was similarly attacked by his dog. And even that dog was not notorious to be aggressive to strangers.
May be you should also try the vet cause sometimes it happens that internal ailments cause them to suddenly behave differently.

Yep, I would definitely say to seek professional advice. There is obviously a reason for the dog suddenly turning like this, it's just a case of establishing what it is.
Once that is sorted then you should be OK.