I am wondering about breeding age for studs. Eskie boy sired his first litter at 10 years old with our eskie girl(Dam was 3) and produced 4 very healthy, strapping pups (one with a single, blue eye-not related to sire age). Recently, at age 11, he sired a litter of one with same dam. Growing up with breeders, I don’t recall ever seeing a singlet even in small dogs-do I assume this is related to sperm viability? I am wondering how common a single pup litter is and if it could be related to paternal age? By the time our girl is ready to breed again, he will be closer to 13. Is there any reason not to allow him a final hurrah? (Other than AKC?). I think our girl much preferred having an only child, and the puppy really thrived!