How do I stop my Chihuahua from being aggressive towards other dogs?
If going to the dog park made my dog that uncomfortable, I would not go back there. It can be a dangerous place for any dog, but especially a tiny dog such as a Chihuahua. As far as visiting dogs, dogs have a wide variety of body languages and behaviors that are designed to communicate their status and emotional state to other dogs without inflicting bodily harm. I don’t generally interfere in dog/dog relations unless a dog is harmed or in immediate danger of such. If other dogs visiting is an issue, don’t have them visit, or put your dog in his crate when they do.
Have your friend and her dog accompany you and your chihuahua to the dog park. Have her and her dog stand at one end of an area and you and your dog at the other. Walk towards each other, and if your dog barks or growls at her dog (before you get close to each other), immediately turn around and walk the other way. Your friend should keep coming towards you. Once he calms down and stops barking, turn back around. Your friend and her dog should just be passing you, and at this point your chihuahua doesn’t have a chance to get emotional. Try this several times, hope this helps!!!