Recently Neutered Dog Now Getting Aggressive

Two weeks ago we fixed our 2 year old male pit. This past week him and his 18 month old biological sister who's also a fixed pit bull (done when she was little) have gotten in 2 fights.

They have never fought before until now. Both fights started because of the female licking the males face then he growls and a fight starts. Neither dogs have ever been aggressive towards humans nor other animals. Need help!

Gale's Reply:

There are a couple of possible reasons as to why your male is now picking fights with his sister after being neutered. One is his developmental stage. Although they reach sexual maturity much earlier, pits don't reach social maturity until between 14 and 36 months. It's at this point that a dog's adult personality and disposition towards other animals become apparent.

Owners are sometimes caught by surprise when a two or three year old dog suddenly becomes less tolerant of others dogs for no particular reason. Very often, the reason is he's reached social maturity.

Another possibility is he may not have been feeling well after his surgery and just didn't want to be bothered by his "pesky" little sister.

In any case, the reduction in his hormone levels will be gradual over time. Neutering sometimes lessens aggressive tendencies, but not always. If it does, the effects won't be immediate. It may take a couple of months for you to notice any difference that could be attributed to his surgery.

Meanwhile, it's important to manage the environment to avoid any further fights between brother and sister. In other words, intervene BEFORE anything happens. And, NEVER leave them alone together unsupervised.

It would be a mistake to let them 'work it out'. Once fighting between two dogs becomes part of their repertoire, it can become habitual and it can escalate to the point of being deadly. So, make the needed adjustments to keep everyone safe.

If your dogs aren't trained in basic obedience, I highly recommend you address this. Your dogs need structure right now and obedience can provide that in a positive way. You may also find it helpful to read How to Be the Leader of the Pack - And Have Your Dog Love You for It! by Patricia McConnell.

By the way, whether or not his dog aggression lessens down the road, you did the right thing by having him neutered. It's better for his health in the long run. He'll be less likely to roam. And, of course, there will be no accidental litters.

Good luck. Feel free to post back with more questions or to let us know how things are going.