We recently took in a foster dog and my dog has become aggressive. Why has my dog changed all of a sudden?
I adopted an 8 month old0 Pitt/Vizla mix from the humane society 4 months ago. She was an extremely great pet. Very loving, we could poke at her paws, ears and mouth. She loves to play with other dogs. This past week I began fostering a 10 month American Bulldog that she had previously played with. He is also a loving secure dog. Since the foster has come into our lives - my dog has become aggressive to my husband and myself. She won't let us look at her paws or rub her belly. She begins to low growl and then snap at us. She has been in training since I got her since she is a somewhat frightened dog. I'm at a loss, I don't want to lose her, and am willing to find a new home for the foster (we were planning on adopting him). Why has she changed all of a sudden?
There are many reasons that a dog can become aggressive:
Vaccination Coming into maturity and wanting to establish a higher rank Jealousy, etc.
None of that really matters at the moment. What's important it making the decision to fix the problem or to give the dog up.
Frankly this dog is the way it is because you have allowed it to display bad behavior without doing anything about it. So the problem falls to your shoulders. I don't want to offend but I also won't sweet talk the issue.
In my opinion the solution needs to start with three things all at the same time:
3 - While both of the above things are happening you should be showing your dog that you can be an interesting, fun, and consistent pack leader. This is done through MARKER TRAINING.
Marker training is simply a motivational training method to teach a dog a language that allows the handler to communicate with their dog. In the beginning markers are used to teach behaviors (come – sit – down, etc.). With experience, it will be used in the daily life of living with your dog.
So the first two points establish yourself as a leader, the third shows the dog that there is a fun and interesting side to you.
As far as this new dog goes, in my opinion, all of these problems are a result of the mistakes you made in how you introduced these dogs. Don't feel bad, most inexperienced dog owners make the same mistakes. I wrote an article titled How to Introduce a New Dog into a Home with Other Dogs.