I think it's great that you've come here for advice before committing to breeding your dogs. Please understand that the advice offered is to ensure the best interests of you all, no-one is having a go at you. Unfortunately Chihuahuas are a breed fraught with problems in breeding, there are so many potential genetic and whelping risks. As previously said, only this week we've had a thread started by someone who lost their bitch after whelping , tragic, but it happens. If you could reassure us as to which health tests you've found out to be necessary prior to breeding your dogs we would appreciate it.