Hello, I viewed your pictures of your dogs.  They are very pretty.  I noticed that you have a red merle.  You do need to be very careful in using merle in your breeding program.  I don't breed merle because it is not a color pattern I like, but I know that there are some dangers if you aren't careful.  I believe there is something about that on the Chihuahua Club of America site at 
Merle Guidelines
I've only seen one red merle and i did not recognize it as a merle.  Apparently, the red merle may fade as the dog gets older so that the dog may appear to be just a reddish fawn color.
Lynnie