GSD Mix bleeding from penis?

Pay attention to the bleeding and note the answers to these questions to help your vet out tomorrow.

1) Is the bleeding from the sheath, through the prepuce? (Sheath is the fleshy covering of the actual penis, and the prepuce is the opening to the sheath that allows the penis to extend and retract.) Or is the bleeding through the urethra? (the opening of the actual penis that emits urine)

2) Has the dog been drinking or urinating more frequently than normal, and has it been having accidents around the house?

3) Does the dog show any sign of pain during urination? Does he shiver, yelp, or squint?

4) Does his urine stream appear strong and normal, or does he start and stop his stream, or dribble before or after he starts or finishes?

Accurate answers to the vet's questions will help them get the right diagnosis and treat your dog economically.

Best of luck, and I hope it is only something minor.

ADDED: That's good. Makes it less likely to be a stone, and more likely to be an irritation of the exterior of the penis.