Riley and the Foster Dogs

I don't know Riley's past, but based on his reactions towards dogs he doesn't know, trainers have pointed out that he is fearful of new dogs due to improper socialization with dogs when he was a puppy. Dog who were not exposed to a variety of dogs during their learning period (up to 3months of age), develop fear of meeting new dogs, and that fear may easily turn into aggression because they want to protect themselves from the new dogs. In their minds, "Offense is my best defense." So that exactly describes Riley. He is fearful of new dogs, especially ones that are bigger than him. However, after a day or two of socializing him with another dog, he can live peacefully with them in our small one bedroom apartment. I foster dogs for non-profit organizations (Scooter's Pals and PROS Pug Rescue of Sacramento) that saves dogs  who have lost their homes or about to be euthanized. I do admit, one of the reasons I foster is to get Riley more accepting of new dogs. I never force the dog on Riley, and I never put the foster dog in any danger. Of course, we are constantly trying new ways to improve his behavior in hopes that he can shorten his adjustment period of a new dog. Here are some ways I've been socializing Riley to new foster dogs:

1. Meet in the neutral location such as a park for greetings.
2. Keep them in separate rooms when the foster dog arrives inside the house.
3. Tether the foster dog, walk Riley into the room and have him focus on me so that the new dog isn't scaring him
4. Walk Riley back and forth until he's comfortable with the other dog in sight.
5. Have them greet for 2 seconds on leash, then call him back to me so he doesn't get too scared when too close to the new dog for a long time. The next time, I have them greet for 4 seconds instead of 2 seconds.
6. I repeat this until Riley offers to play with the dog. 

At first, it took him more than a week for him to get along with the first foster dog I ever had. Over a year has passed and 10 dogs later, he is able to get along with a dog within a day (situation and dog dependent). So it's not the foster dogs who need to thank me for saving them, it's them that I have to thank for improving Riley's behavior towards dogs. Here are Riley's foster siblings in order (fostered non-concurrently):

Roxy, 5 year old Lab/Terrier Mix

Milo, 2 year old Queensland Heeler Mix 

Mercury,  8 year old Rat Terrier Mix

Daisy, 6 month old Jack Russell Terrier Mix

Pico, 2 year old Toy Fox Terrier/Chihuahua Mix

Toby, 1 year old Chihuahua/Terrier Mix

Sedrick (not a foster but stayed for 1 month), 13 year old Yellow Labrador

Oscar, 3 year old Daschund/Chihuahua Mix

Chopper, 8 year old Fawn Pug

Bob Barker, 4 year old Pug Bugg (Boston/Pug Mix)