Gregg Miller is the 64-year-old inventor and entrepreneur who created Neuticles, silicone implants for male dogs to replace testicles after neutering, so that a dog's appearance...down there...doesn't change.

It's made him a fortune.

Do dogs care about this?

"Yes, they do," Miller says.

But do the owners? Uh, yes, they do. Over the last 20 years, Miller claims he's sold over 500,000 sets of Neuticles. The average pair costs $310, though some cost a lot more, like the $2,800 watermelon-sized custom set Miller made for an elephant in a zoo.

Yes, I can believe that.

The eureka idea for Neuticles first came into his head while he was at the vet getting his own dog fixed.  He asked his veterinarian if someone made implants, "so Buck can maintain his God-given natural look." The vet told him that was "the craziest damn thing I've ever heard of." The vet later reconsidered a testicular implant idea as not so crazy after all and the two men started working a prototype.

Eventually, Miller said he and a group of 30 more local investors came on board spending over $100,000 to develop Neuticles.

After media attention about their idea (ya think?) soon wore off, there were some very lean years ...but through perseverance and marketing and veterinarian networking and DOING LIVE RADIO INTERVIEWS WHICH INCLUDED GIVEAWAYS, (what jock wouldn't want to set up a 9th caller with free fake dog balls...that's great radio, right there) ...his business went, wait for it, NUTS!

The most popular Neuticles are now made of solid silicone which is textured to prevent scar tissue from forming. ($469 a pair).

"Mind your own damn business." are Miller's words to the haters and scoffers who detest his product even though after 25 years into the product run, nary a complication. Ever.

Neuticals has even been banned in a few countries, a fact Miller is proud of, but he doesn't let such details stop him from meeting demand from customers in those far-off lands. To get the product through customs, he just re-brands it, calling it a stress ball.

Neuticles come in 11 different sizes to fit a variety of pets, and Miller has expanded his product line even turning some Neuticles into pendant earrings and necklaces.

Oh, and he's written a book called, "Going...Going...Nuts."

CNBC.com - Fetch Fake Dog Balls Boy

Indeed, fake dog balls has turned out to be his most lucrative endeavor. Miller calls his home outside Independence, Missouri, "The House that Neuticles Built."

He believes his invention has actually encouraged some pet owners to neuter their dogs. "Their dogs don't have to be turned into eunuchs anymore, and, to me, that's priceless."

CNBC source here.