How do I socialize a chihuahua puppy who is extremely territorial?

Here are three great places to start.

Good luck and always remember. A dog really is a dog.

^^^ Except when it’s a llama.

^^punchline to the dirtiest joke ever

^^^ Or, as a novel idea, the opening sentence to the great American novel.

Take her to a good obedience class or puppy kindergarten. She will get plenty of socialisation at either.

As @rooeytoo suggested, obedience classes are so very worth it. You can get specific ones for reactive dogs (which is what yours is). Obedience classes are wonderful for both humans and their canine companions. Remember, it’s not just your dog who needs training. How you react while she’s reacting is incredibly important. Be sure to research the obedience trainers/schools though. When you find a good one, it’ll be the best money you’ve ever spent. Needing classes doesn’t mean you are a bad owner; it just means you need to learn some extra tools. If you have any questions, feel free to PM me. We are going through this right now with our little dog.

I just think you need to teach your dog boundaries. I have 2 dogs 9 & 10. I have had them both since they were puppies 6wks for the 10yr old and 10wks for the 9yr old. I have learned a lot. The 10yr old is a little more excited, anxious and nervous which never ended well when meeting new dogs that had an energy level similar or higher than his also he had a problem with dogs bigger than him so I continually have to boost his confidence to keep him in check and remind him of the boundaries compared to the 9yr old who is more submissive and calm and has no issues meeting other dogs the 10yr old is much more work.

Both dogs were treated the same and both were socialised with the exclusion that the 10yr old ironically went to positive training classes and passed with flying colors while the 9yr old never had training classes.

So maybe all you need to do id set limits for your dog and eventually your dog will understand what you want. Mine finally get it. Thats all I’ve got..hope it helps some. :)

I guess if I was a very fragile small dog around big scary dogs I would react the same way.
The dog is trying to protect Its owner ( normal for dogs to do), but encounters much bigger foes.
Brave little dog. Watch “the Dog Whisperer” for advice.
Dogs pick upowners feelings and react.

The little guy is probably either afraid of them, or he’s protecting you (or both).

This video (and Victoria Stilwell in general) helped me a lot in dealing with my rescue dog, who had severe fear and protective dog-aggression (she is fine once she gets to know a dog, cat, or even rat): http://www.youtube.com/watch?v=fCaMTTOxQFE

http://functionalrewards.com/BAT-basics.pdf
^Using this page I’ve managed to get her to walk past another dog without any aggressive behaviour. It’s taken a month, but we got there. I wish you all the luck! :-)