No female dogs at all?
Anybody find it strange? Especially considering how many different types of dogs there were. Maybe that dude specially engendered them or something.
shareHow do you know none of them were female?
shareI guess I assumed it because none of the voices were female, which is not proof. I see your point.
shareChances are Muntz always had female dogs in his ship,or he wouldn't still have such lovely purebred dogs in South America 60 or 70 years later. We always talk about "all the dogs in this [live-action, obviously] movie are dead now," but this is a film in which the dogs at the beginning are long dead even before the middle of the film . . . unless he was an even better scientist than he's shown to be, and arrested dog aging but never got around to arresting his own.
shareHe seemed pretty nimble for his age.
shareYou're right; what makes skin sag, dry, wrinkle, get brown spots, etc. is unrelated to the aging of other organs and systems. (More or less.) When a joint like the hip, knee, shoulder, or ankle goes, it's usually because of trauma (sometimes, in the 70s or 80s, surprisingly mild trauma). Sometimes lifestyle changes we already know about can decrease the chance of those injuries.
But if he'd found ways to either prevent or address the small failures, all systems would remain "go" and he would, indeed, be nimble. (Given that pulmonary, circulatory, renal, and all the "squishy" stuff is more complicated -- hey, he was a genius.)