My dog growls and shows teeth. Should I be concerned about aggression?

It sounds like Muggs is bring quite seriously aggressive. Firstly you should have him checked by your vet for any medical reason that could explain his behaviour. Following that you need to go back to basics with his training and give him the confidence not be nervous. In a difficult situation like this I would highly recommend employing the service of an animal behaviourist. Your vet may be able to help by prescribing medications but it usually comes down to behaviour and training.

At this point, I think you need to have a professional trainer/behaviorist examine your dog and try to come up with a training plan. That is very concerning that she is aggressive and I think you need some professional help before someone in your family is injured. Call your vet and see if he/she can recommend a good trainer in your area.

It sounds like Dune may simply have been startled and reacted fearfully - growling and barking are common signs of fear in dogs. If he settled down quickly and has been acting normal again since then, I wouldn't necessarily worry. If this behavior continues to occur over the next few days or weeks, then I would recommend consulting with a veterinary behaviorist or a good reward-based trainer who can evaluate him in person and help determine why this is happening, so that you can put together a training plan to work on it. You can search for a board-certified veterinary behaviorist in your area here (www.dacvb.org) or a qualified trainer here (www.ccpdt.org)

Oh dear! Growling when you pick her up is a major red flag for future problems in a puppy this age - this is not normal, and needs more help than just socialization. From your description, it's hard to say if her behavior with the other puppy is normal play or aggression. I would strongly recommend making an appointment with a veterinary behaviorist who can evaluate her in person and help you put together a plan to work on these issues - it's best to do this as soon as possible, since early intervention gives you a much better chance of being able to change this behavior before she grows up. I'm not sure what part of Canada you're in, but your regular veterinarian should be able to help you find out where your nearest board-certified veterinary behaviorist is so that you can make an appointment. In the meantime, I would try and avoid doing anything that tends to make her growl - instead of picking her up, for example, use treats to encourage her to come to you. I would also not recommend any kind of punishment for this behavior, as this has a high risk of making things worse over time. The behaviorist can help you identify what kinds of situations tend to trigger the growling, and will put together a training plan to work on this issue.

Growling and biting isn't inherently a sign of illness, but it doesn't hurt to schedule a vet visit to rule out any issues, however I would be more concerned that a puppy is biting and growling at only a month of age and acting aggressively. I highly recommend trying to find a veterinary behaviorist in your area that can deal with aggression, or working with a trainer on basic puppy obedience so you can start to instill some ground rules and learn to communicate with each other better. http://www.dacvb.org/about/member-directory/

What you are describing may be normal puppy behavior for Bear because some puppies respond very poorly to dominance type of behavioral training. However, I would be concerned with the behaviors that you are describing. I would recommend contacting your veterinarian or the foster organization for a recommendation on a trainer to work with to have someone else observe Bear's behavior to help you decide where to go from here. The longer this behavior continues, the more serious it will be become, so this needs to be dealt with immediately. In the meantime, I would not reprimand or challenge Bear since that seems to escalate the situation. Good luck! I hope that was helpful. Thanks for using Petco Pet Education Center, formerly Petcoach.

I strongly recommend you consult with a professional, in-home dog trainer. You need a trainer to come to your house and see the behavior and the interaction of all the family members with the puppy. This is your best bet. Aggression problems need special care and it is not recommended that you try to correct this on your own. You may give him the wrong signals and make him worse. This needs to stop before he hurts someone.