Hi Kathy, welcome.

It’s hard to say what’s actually triggering Otis to go after Ollie but just from your post, it sounds like there may be some over stimulation in action. Whether the cuddling and brushing is stimulating Otis to the point of resource guarding you or maybe its stimulating an excitement in Ollie that Otis feels he needs to tone down.

Regardless, at this point, until you get it figured out, I’d have Otis on a leash or a drag line at all times. Ollie shouldn't be living in fear of being attacked.

The moment you put Otis down, engage him in another activity – some fun marker training or a toy distraction. Keep him restricted with the leash until he settles down and don’t allow the attacks to continue.

What does Otis do when you’re brushing Ollie? And I understand that you probably enjoy picking them up and coddling them but how do they feel about it? Are they squirmy, do they try and get down?

How are they together when you’re not interacting with them? If they’re of a more reactive nature, sometimes we can bring an excitement into the mix that disrupts their natural balance. I would be keeping my enthusiasm, when they’re both together, to an absolute minimum and encouraging calm interactions with them.

Bumping this one up... any ideas? I'd be interested in reading the replies.