Whats wrong with my dog?!?

My dog is 8 years old and is not fixed. She has sores all over her body and is losing her hair on her chest and lower back and butt. her nipples are bigger than what they are suppose to be and her ear is infected. my poor dog is miserable. i have given her baths and flea products but she has gotten worse by the day. I don't think there is anyway that she could be pregnant. We do have another dog, but she is female, and she is also related to my dog. they are both behind a closed fence all day and they only time they are not is when they are in the house. PLEASE tell me if you know anything about my dog's condition.