New, 2nd dog - how to prevent play aggression?

I always recommend that the most important criteria when choosing a second dog is to match the energy levels and types in order to have a more peaceful and united pack and it seems that you might have a case of unmatched energies here. But also, you have an 18 month old dog who is in full hormonal peak and just becoming and adult, many dogs who displayed no dog reactivity will start around that critical 18 month old period. And on top of it, introducing a new dog can be tricky even with the best of scenarios, adjusting can be difficult but time, discipline, consistency and positive reinforcement usually does the trick.

I like the previous answer where looking for the triggers in Dodge's behavior as well as Roxy's. To prevent little spats and making sure they do not turn into full blown fights, you have to stop them way before they happen, a kill it in the egg type of approach. I look for stare downs, different body positioning and such, I make sure to break up the wrestling type of play if it seems to escalate, I listen to the different tones of their voices when they play, I do not allow toy stealing or resource protecting of any sort.

But when Roxy does react, she must be made to understand that it is not appropriate and in order for her to understand that, she must know you have her back. So make sure Dodge does not play too rough or become overbearing, overwhelming or a bit of a bully. If you take care of things, she wont feel like she has to. If she feels disrespected or bullied, she will react, if she feels she needs to protect herself, she will. But if she feels you have it well under control, you have much better chances of her not getting upset.

You say Roxy is very bonded with you and your husband so use that, deny her attention or proximity to you when she reacts badly, you are the reward and she will need to behave a certain way to earn your attention and affection. If every time she misbehaves you push her away or put her in her crate, she will quickly realize its much more fun and pleasant to behave the way you want her to.

As for the bonding, walking them as a pack, doing activities with them both, teaching them games they can both play together will help increase their bond as much if not more than just wrestling around.

Sounds like you're paying a lot of attention to Roxy and the signs of escalation in her demeanor. Are you watching Dodge to see if there are any triggers causing Roxys sudden change in mood? There might be a certain action or behavior that causes Roxy to snap - and maybe identifying that and correcting that behavior, not just the reaction, could help.

Corgis are NOT calm dogs. They are fun little balls of energy. Very active, dominant and confident. Same with most terriers and terriers do not like to share.

In general "reward" whichever is the calmest. I hope the trainer helps you and it works out. Many dogs do better as an only dog and can never be happy having to share parents with others. Terriers and Corgis are both very strong willed. If you wanted a calming influence a Basset Hound or Golden Retriever would have been a much better match.

Best of luck!

Theres an excellent free webinar series from the ASPCA which includes dog body language and play. Highly recommend it to anyone who interacts with dogs!

http://aspcapro.org/canine-communication-webinar-series (http://aspcapro.org/canine-communicat...)

Basically, even if play is going "well" you should have frequent breaks. See if one dog will return to the other or avoid. Make sure they both get plenty of exercise before playing so they have more impulse control. Dont think that play should substitute long walks for tiring them out. Work on impulse control exercises. Make sure they each have their own spaces (crates) and that you give them each individual attention.