My heart is sinking over how Puca is continuing to react toward dogs. I'm struggling to understand how he could have just come to me this way as a 3 month old puppy. From the first time I introduced him (At 3.5 months) to a dog in public he showed signs of rejection. Fear, irritation, etc. Lowered tail, bowed head, occasional showing of the teeth if dogs got too close to him, obviously only tolerating being sniffed. I have tried different possible environments in which to expose him. I have no idea why he is like this or how to correct/redirect his behavior. A big indication that it was getting worse was on a trip to Tractor Supply. We were in the store, not too many people around, but there was a couple with a dog in there. Adult pit mix or something, friendly enough. It walked past us barely paying attention to us and once Puca saw him he immediately began barking. Most recently I decided to take him to a festival. I knew there would be people and other dogs but Puca loves people and is well mannered. Of course my heart sank when we were standing in a tent with a vendor talking and another dog walked past (probably 15-20ft away), as soon as Puca saw him he tried to take off after him, of course barking like a lunatic. I couldn't believe it! I thought we had recovered and we continued on. Shortly after, we passed a severely overweight female Dachshund. Puca walked in her direction, they were probably maybe two feet away from each other before this little dog ran up and snapped in Puca's face. Of course I immediately pulled him away but he was already reacting and sounded like he was going to kill her. I have no idea if Puca's body language was threatening to her or if she was just a nasty dog. From my angle, behind Puca, he was just sniffing. I was saddened to see that there were some ill-behaved dogs there. Later on from inside another tent, I saw a different Dachshund bark and lunge at a dog. Puca and I had been within sight of THIS Dachshund earlier and neither paid each other any mind. I can't stand when people take aggressive dogs out into public and I have a feeling I am turning into one of those people that I can't stand. Puca's behavior is so unpredictable. I've contacted his breeder and she hasn't had this problem with her male or the puppy they decided to keep. She says that her female is ok around other dogs but becomes reactive once they get in her face. None of the other puppies from the litter have reported any behavioral issues such as this. I am at a loss. Any advice would be much appreciated. I am looking into training classes now. I just do not know what to do.