aggression towards other dogs

Question
I have a 10 month old male mini schnauzer. He was neutered when he was 4
months old. I took him to a 6-week puppy training and he did well with other
dogs. I started him in day care for 2 days a week when he was 5 months old. At
first it was great then he started being aggressive with the other dogs. He has
since been kicked out of day care and acts like a terror when around other dogs.

Answer
So what is your question?

If he were my dog, I would get him into on-going obedience classes for several months and work with him every single day. I would practice "Nothing in Life is Free" with him, and have everyone in the family do this also. http://k9deb.com/nilif.htm I might even put him into a Gentle Leader Headcollar. http://bargraph.com/gentleleader/

I would also have his thyroid levels tested, as hypothyroidism can cause aggressive behavior in some dogs.