My husband and myself have a 9-month old Jack Russell Terrier, which we have had from 8 weeks. Until recently, he was an extremely lovable, sweet puppy. About a week ago when I went home to let him out of his crate at lunchtime, he displayed extremely aggressive behavior towards me (growling, snarling, baring teeth, etc).

Since the first incident, he has displayed this aggressive behavior only towards me about 5 more times. He is currently crated during the day and was sleeping with us at night until he began displaying this behavior towards me in bed (he is now being crated at night). We have an appointment in a week to have him neutered, and we know we will need to work with a trainer to correct this aggressive behavior. As I stated, this behavior is only towards myself; he is interacting as normal with my husband. Does anyone have any suggestions in the interim? Best ways to interact, discipline, etc?

Thank so much in advance!

See what he is like after he is neutered. That might change everything.

I'm concerned about his lack of time out of his crate, outdoor time, and socialization. He's been crated all day since he was a pup of 8 weeks? Ever play with other dogs at all?

We take him on walks each day, and also play with him outside with his toys each evening. He's been around tons of other dogs -- we do take him to dog parks and he also has several dog friends that we have play dates with. He plays well with others, however, he has become quite the excessive humper with other dogs though, to the point that he is almost relentless.

I would think that you are witnessing a terrier in full blown terrier mode.

Jack russells are very cute, bubbly and small.. but at the end of the day, they are still a terrier.. and terriers were designed to be tenacious and kill things.

I am a firm believer in researching your breed. Once you understand what your dog was designed to do, than handling him will be a bit easier, plus you will understand why he does what he does.

At the moment, with him growling at you and only you, tells me he is struggling with the pecking order you have created. He is an intact male that is going through puberty.

Just think of him as the 12 year old son that is being defiant and rowdy. Same thing.. He is testing the waters and seeing what he can get away with.

I think what you are doing is correct, by making him sleep in his crate at night. Some trainers believe that letting a dog sleep in bed with you will open a door to your dog believing he is equal to you (which you never want). I, however; believe that stands true to certain dogs.. and your pup might be one that fits that category.

Is the crate he in a plastic, covered crate? If so, maybe purchase a wire crate and leave it open. Take away his "den" and his area. Put him out in the living room in that crate with everyone moving about.. That will teach him he has to share his space and should eliminate the cage aggression.

Cage aggression, which is what your pup is doing, can pop up at any time. Typically, its from dogs that spend too much time in a kennel/crate. This usually happens if a dog is boarded often or is in a home with lots of other dogs. Cage aggression can also appear with dogs that are wanting to be in charge. Basically, he is telling you that this is his home and you're not invited.

His humping is the start of a bad habit. Your dog should have been neutered 3 months ago. Now you get to deal with the aftermath of an intact, dominant/aggressive dog. Once neutered, will this disappear? Maybe.. Usually when dogs hump other dogs, they are trying to become the top dog. It's a dominance thing. It may go away after he's neutered, it may not. My advise.. start running around with a potent mixture of vinegar and water in a squirt bottle and correct the behavior. He may continue to be a humper, but he better be behaved while he is on "your time".

Your little pup is changing his behavior. It could be hormone induced, or it could be behavior induced.. either way, a good dose of obedience with a side of exposing his securities *his crate* is on your menu! The obedience will enforce that people are in charge and he is last. Another good trick... Feed him dead last.. after you and your family is done eating with him in a sit or down position the entire time. Humans eating first and him last is a major sign telling him that "I am in charge, and youngsters like you, dont get to eat with the pack, instead, you get my left overs and you eat when I say you can."

Some dogs are just born like this. Is he going to eat you alive at night? No.. But it is something you're going to have to recognize and control. Once he is under control, this is going to be something you are going to have to constantly supervise.

Just be subtle about everything. You don't need to pin him to the ground, shake him and spit on his food.. Just make him do things.. feed him last.. expose him in his crate.. and.. once again, make him do things.. make him sit for EVERYTHING.. make him lay down *this will be more challenging once he catches on you are wanting to be in charge*