Need some advice

[Canthinkofaname79]

I have a 16 month old shihtzu. He's usually very calm, gentle, etc. However we have spent the weekend with another dog (who's he met loads of times before and been fine) and my dog got really possessive around treats and chews. He would steal the others dogs treats and chews then snarl at him, he ate the other dogs food, he weed on the carpet, he went in the other dogs bed and cuddled up to the other dogs owner. This was a place where my dog had stayed before but this dog hadn't and this all seemed to be really dominant behaviour. It was so out of character for him. He is also quite scared of dogs he doesn't know.
Whst can I do? It was pretty mortifying, before this weekend I thought I had a well behaved dog!

Bump.

Im guessing this is your first dog?
You should never put anything between dogs that is high value - so that includes ESPECIALLY food, treats, toys. Of course they would compete for these things. If he is staying he should have his own bed in a crate where he can chill out. Feeding & toys are seperate not shared and treats are given seperately.
Him urinating is territory marking. You need to remove all things that they can compete over and give seperate spaces for chilling out. Sounds stressful for both dogs.

Nothing was put between them. And they absolutely had their own spaces. He went over to the other one and stole his stuff. They were fed in separate rooms. I'm home now, it was for the weekend. He's spent a week with another dog before when we went abroad and didn't display any of these behaviours.
Nope not first dog.

But you are missing the point, if he was able to walk over to the other one then thats fair game in his eyes - so if you dont want agression dont give them anything to fight over, no treats, no toys, toys should never be left lying around anyway as it decreases their specialness in the eyes of the dog. So yes a fundamental error - you did leave treats that could be argued over in as shared space.

Just because it was another dog in the past is no guarantee that he will behave the same. Do you get on with everyone the same? No, we all change how we are depending on the person - dogs are just like that too.

No toys or treats around at any time

keep dogs separated, using leads if you need to.

if he ate the others dogs food clearly they weren’t being kept apart so this is easily fixed

much like people not all dogs like all other dogs

Thank you. The food was in separate rooms but someone left a door open. He normally gets on really well this dog.