I find myself wondering about dog orgasms recently. My question is, at what age can a dog have an orgasm? Is it different between males and females?

From my experience, they begin to orgasm about 8 to 9 months old.
But, they don't yet learn how to mount at this young age.
My dog first mounted me when he had 10 months and did not tie. (Due to lack of experience)
He only tied to me when he was one year old.

Larger breeds may require a lot more time to mature

A poodle / mutt mix I've met liked masturbation and enjoyed a complete orgasm at the age of 7 months. (He's beautiful! Looks like the dragon from the movie Never Ending story)

In females I'd think it needs a lot more time... I have had no experience with females

To make a fine distinction, the ability to have an orgasm, the cascade of pleasurable contractions in the prostrate and pelvic muscles and release of tumescence, comes even earlier than the ability to produce sperm and ejaculate.
However puberty, the onset of fertility, comes long BEFORE mental/emotional/behavioral maturity, and the sort of "scarred for life" consequences of a bad early experience can ruin the dog's confidence and desire, for life. Therefore, it's best not to obsess about "how soon can I get it on with my puppy," and limit yourself to innocent belly-rubbing until a bitch's second heat, or at least a few months after the first one, and the corresponding age in a male dog. Your over-riding priority is to earn your pup's trust, to protect him and never fail him.

Dogs - as humans - can have orgasms at a very early age, long before going into puberty or reaching maturity. I never tried for obvious reasons, but I belive that even puppies can experience an orgasm. After all, it's just a hormonal-bodily function.

Prank