Sometimes one, or both, of the testicles won't descend. The neutering procedure becomes more invasive--like a surgery, and therefore more expensive. My yorkie puppy has two testicles the size of walnuts
(which, by the way are being removed on Tuesday), but my toy poodle only had one testicle until a couple weeks ago. He was just over three months old when it finally dropped.
Don't sweat it. They could very well drop by six months, but if not, the vet will be able to take care of it.
