Sudden Aggression in Dogs

A medical problem could be behind dog’s alarming behavior changes.

Q. Our 2-year-old female German Shepherd Dog-Doberman Pinscher mix, Corey, is a spayed, indoor dog. Lately she has become aggressive and violently angry for no reason and reacts negatively to most outside stimulants, such as other dogs or children.

She and our 2-year-old Doberman Shane live indoors. They get plenty of exercise when we play fetch or ball or as they run and play together. We do not take them for walks on leashes because of Corey’s behavior. We have two geriatric cats that she seems to love and she’s never tried to harm them.

Several times she has charged my husband or me when we’ve come toward her. We loudly say, “Corey it’s me,” and she stops short of actually attacking, but it still concerns us that for those few seconds there doesn’t seem to be any recognition.

We are looking into the possibility that she may have some sort of disorder that causes her to lapse into her Demon Dog alter ego. Aside from medication, what can we do for her? We’d love to be able to take the dogs for walks and car rides, but with Corey’s behavior as it is now we just can’t take the chance.

A. Your description of Corey’s sudden and unpredictable aggression makes me concerned that she may have a serious health problem, so you’re wise to be checking into that. Your veterinarian may need to do blood tests and other diagnostic procedures to rule out problems with thyroid imbalance and other biological contributors to sudden aggressive behavior.

When a dog’s behavior and personality suddenly and drastically change from calm to aggressive for no discernable reason, particularly when that aggression is directed toward well-known family members, this is more than a training issue. Corey may need medication, as well as training, to normalize her behavior. Take her to your veterinarian right away.

Once medical causes have either been ruled out or taken care of, ask your veterinarian to refer you to a professional dog trainer or behaviorist who has knowledge and experience working with aggressive dogs. That way you’ll get some hands-on help teaching Corey good manners on walks, car rides, and other outings.

Article Categories:
Behavior and Training · Dogs