Brother and Sister

Question
hello, I have 2 lab/German shorthaired poiner mixes.
They are brother and sister and are gunna be 8 months old in 3 days.
Elmo(male) isn't fixed yet because he hasn't fully dropped.
Cookie monster(female) isn't fixed either and i THINK she might be going into her first heat?
I was watching them play, and then Elmo started mating with his sister?!? and then she started doing it back to him!?!
I dont know what is going on, but i was wondering if you have any advice on this matter!
I really don't want her having puppies soo young, or with her brother.. heck, I dont want them having puppies at all!
They have NEVER been appart since birth.
Is this like.. a play thing? or actually mating?
When he mounted her.. she just sat down.. that little weirdo
My friend bred bro and sis chihuahuas(on accident) and they ended up with a puppy dead, and one with a crooked eye.. I dont want to put my dogs at risk!

Answer
Hi Kasadee

It sounds like the female is coming into her season.  So keep them separate for at least a month!! Most people think they can keep them apart until she finishes bleeding and that's not true.  It's when the bleeding stops that they are the most receptive.

If your male hasn't dropped by 8 months old, chances are he has a retained testicle or has cryptorchidism.  This is trait can be passed onto the pups so you don't want to breed a dog with this condition.  And if a testicle is retained the dog is at a greater risk for cancer.  You need to get this male fixed.

Also doing a in-breeding on these two breeds will double on health issues and any trait that they both exhibited.  At 8 months old they aren't fully mature mentally or physically so you want to ensure they are in top physical health before considering breeding.

My advice, don't wait get one or both fixed immediately.

Good luck