Thank you all for your responses to my husband's question about Peanut. We appreciate your insights. A little more background:
We adopted him from an animal shelter when he was about 2 yrs old - he's half pom and half schipperke - He had been hit by a car and had a fractured hip. We were told that a highway patrol officer had found him injured and brought him in. The shelter vet gave him a temporary fix and neutered him at the same time. We fell in love immediately. He was very shy, limping, and extremely skittish. We fixed him up and found out on a walk that we had a screamer. It's a high-pitched cry; he lunges at the other dog. When we let both dogs close, he tries to put his paws on their back. He also is very aggressive with his hinny-sniffing which always irritates even the mildest of dogs. There are 2 times we can remember in 10 years that he played easily with another dog.
He did well at a couple dog training classes. There was one class in particular that I thought was too focused on choking him. When we tried the shock many years ago, we did it only once. I cringed, felt horrible and got rid of it immediately.
Our other 2 dogs, Tippie (Pomeranian) and Dixie (Schipperke) arrived 2 years before Peanut. They bossed him but he seemed happy knowing his place in the pack. We lost our little Schipp, Dixie this year and many other changes have occurred including moving. He gets along with our Pom, 13 yrs old and 3.5 lbs. She's always been the Alpha of all 3.
Peanut has now started screaming when he sees people. It scares them, but if they approach, he greets them with glee. He loves people at the door. I've been watching the Dog Whisperer and noticed that Caesar uses a slip collar high up behind the head. I tried this and because it holds Peanut's head up and forward I was able to walk normally past a boxer that was following us. This doesn't stop his agitation and he never fully recovered from his skittishness. We have always had to be careful not to touch him suddenly - he flinches every time. He also lately has been slipping, crawling onto my lap when fearful. This makes it difficult to see the keyboard on the laptop, which he is doing right now! If you still think there's nothing we can do ourselves, we will definately try a doggie shrink. I just want him to be happy.