When the female is in heat.
A male dog is a Boy and a female dog is a girl. If they breed, then they could have puppies.
Male dogs can not go into heat.
All dogs no matter the breed, or sex, have nipples.
dogs breed by a female and male dogs do cross breed by example: A border collie and a poodle got married and had pups ill be Cross with a border collie and and poodle!
Yes two leopard geckos can breed from the same male and you can also breed them to the male
that means the humper is the master
It depends what your intentions are being. If you intend your dogs to breed, you would have a male and a female for obvious reasons. Other than that it doesn't really matter what sex your dogs are. Keep in mind males tend to be teritorial.
To be honest it all depends on what you want your dogs relationship to be. If you want babies/them to breed then obviously get a boy but if you just want friends get AA female. :D
Advertise in papers, online or mags. Depends on your purpose.
Every single breed, in fact every single mammal on this earth has both male and female of each gender. You don't have all male dogs being a German Shepherd and no other breed or else they'll all be extinct.
I think it depends on the breed. Kid-friendly dogs-- I imagine they get along well with their pups.
Dogs are not mentally adults until 2 yrs old