@curlytails:
Can all the toys (the chihuahua's too) be removed and only taken out for supervised play?
With my resource-guarding shiba, it's "out of sight, out of mind." Knowing that he has a tendency to start scuffles over toys, we put all the high value ones (stuffed and squeaky things, for example) away once Bowpi entered the picture. He still gets his tennis balls in the backyard, because they're plentiful and Bowpi has zero desire to compete with him over those – and he knows this. The fact that we had these lower-value toys to "test" him seemed to help a little... For example, Bowpi would go out to the backyard purely with the interest of sunning herself. Bowdu would start to growl/whine and get antsy and run over to one of his tennis balls and to guard it. But Bowpi would just ignore him, stay far away, and settle down into a pool of sunlight. Once Bowdu saw that there was no need to feel threatened, he would relax. Over time, he learned there was no need to guard those tennis balls.
The thing is, he is reassured that all toys are HIS toys. It was part of both dogs learning to "know their place" in the home, I think. It worked because Bowdu cares about toys, and Bowpi doesn't. If both dogs are toy-motivated, it's a different matter. I'm not sure that dogs understand the difference between "their" toy and "another dog's" -- like this chihuahua might not be content to let Cody's toys be Cody's. Unless both dogs can learn something like a really solid 'leave it', I don't think it's worth it to even give them the opportunity to fight over their toys.
Both my dogs got fed in separate rooms from day one, and I think that's the way it's always going to be. I think for some dogs, that's just a permanent situation.
Super great advice! I totally agree. The only other thing I *might add would be to let them interact with Cody wearing a basket muzzle so he can't really hurt the Chi. They need to sort this out…but you don't want anybody to get seriously hurt obviously. But in my house, if a toy 'causes serious guarding, it goes away.