Two dogs cant get along

Question
I have never had a two dog household so this is new to me. We have 7 year old neutered male border collie mix who is/was sweet, smart, submissive to all people and dogs, and yes spoiled.

We also adopted a female sheltie mix puppy at 8 weeks (Tasha). Her nature has turned out to be not submissive, fearless, but not aggressive. She seems to idolize the older dog and tries daily to initiate play and just hanging out with Winston (the older).

Tasha is now nearly 8 months old and spayed. She is a handful like most young dogs, but I'm starting to wonder is part of the problem isn't Winston. They have recently begun to fight more aggressively even in front of us while we are relaxing. Winston seems to one day be submissive then in a second he will decide he is boss and really go after her. She rolls over for him everytime right away. It looks to me like she is happy to allow him to be beta, but he is confusing her. My husband and I believe we are pack leaders and they do both obey without hesitation. Tasha takes a bit more work, but I expect that with a young dog. She is not allowed to win against our will.

This is now 6 months into this. How long should it take for them to work it out?
Example- we have always left a kong stuffed with something frozen for Winston for years. He can have bad separation anxiety (part of the reason to get the puppy). this morning Ihad to run back into the house after hearing a scuffle inside. He had taken her kong along with his and was guarding them both. He also had control of both rawhide bones. We need to leave the rawhide out because Tasha is in a chewing stage.
I may have over reacted but I took everything away from him put Tasha in the kitchen behind a gate- something I hadn't done in weeks. She was left with the rawhide- he got nothing, both have water.
I'm actually afraid he will hurt her if we don't get this under control soon. He outweighs her by 20 pounds.
Winston is border collie smart- scary smart. He is the best dog I have ever known and I don't know how to help him. We cuddle and play with him as much as we do her. I know that would be a problem if we paid too much attention to the puppy. Both get a long walk everyday (together) and do wonderfully well walking side by side.
What advice can you offer to help my pack become content once again?

Answer

Dogasaur.com Multi-dog households can often have problems related to mixed messages by the owner(s). Are you sure you are consistent in showing them the hierarchy of the house? Tasha's age...8 months...is adolescence so she will be feeling her oats and pushing the boundaries in all relationships. Just fyi.

So what to do? Begin by removing all toys and high-value items from the equation for a while; no valuable resources, nothing to guard over. I suggest investing in backpacks for them from Outward Hound. The act of wearing the backpacks with some weighted items in them (water bottles do fine) seems to give the dogs an extra purpose on walks.

Practice obedience with both of them, separately. Reinforces your role as leader. Brush them, trim their nails, brush their teeth...also reinforces your role as leader. They eat after the humans, not before or during.

You might want to consider a crate for Tasha...I wouldn't get one for Winston if he has SA (I don't know if it makes you feel better or worse, but a second dog isn't usually a good remedy for SA. I would have chosen behavior modification with a pro trainer who knows their stuff, or Chlomicalm prescribed by a vet.

Also, you might want to ease up on the cuddling. It's hard, I know. But as much as we enjoy it, it can actually say something completely different to the dog, opposite of leadership. When the house is more in order you can always reintroduce it.

Hope I helped somewhat, let me know how it goes.

Josh Abrams
Founder, Dogasaur.com