Same landmarks, much bigger puppy
A young Saint Bernard is male when his genital opening sits along his belly, and female when it sits immediately under her tail. Everything about this breed arrives oversized, including the confusion, because owners expect giant puppies to show giant clues and instead find the same small structures as any other breed, buried in considerably more coat. Weight guesses fail spectacularly here, since Saint Bernard littermates can differ enormously while both being perfectly normal. Shrink your focus to the underside, measure the gap between the two openings with your hand, and the answer scales back down to simple.
A two-person job on the floor
Never attempt this check with a young Saint Bernard balanced on a table or held in your arms, because a startled puppy of this size can injure itself and you in one lunge. Spread a blanket on the floor, let the puppy flop onto it after a meal, and position one person at the head offering gentle stroking while the other eases the dog onto its side. Support the barrel of the body as you roll, rather than pulling a leg, and expect drool on everything involved. Thick double coat parts best with your fingers worked down to skin in short sections along the belly's centre line.
Identifying a male Saint Bernard
On a male Saint Bernard, work through the belly coat between the hind legs until you find a small rounded hood of skin with a tiny opening, set a hand's breadth or more forward of his anus. Relative to the puppy around it, the structure looks almost comically modest, which is why owners scanning for something grander miss it. His testicles, in a young puppy, may register only as slight fullness under the skin nearer the rear opening. Judge by the belly landmark and its long separation from the tail end, and a male Saint Bernard announces himself plainly enough.
Identifying a female Saint Bernard
On a female Saint Bernard, the centre of the belly yields only a small flat navel scar once you have parted the coat properly, however deep the surrounding fur feels. Her genital opening is a modest vertical slit directly beneath her anus, frequently shaded by the heavy tail and the breed's abundant rear feathering. Lift the tail, sweep the feathering aside, and angle a light in if the under-tail region sits in the coat's shadow. In this breed the female's two openings can look widely spaced simply because everything is large, so compare the gap with the male pattern of a belly opening, not with absolute size.
Where Saint Bernard checks go wrong
The commonest Saint Bernard error is sheer scale confusion: an owner measures a female's under-tail gap, finds it wider than a smaller breed's male gap, and calls her male. Spacing only counts within the same puppy, belly opening versus under-tail cluster. The navel scar fools people too, sitting flat amid deep coat where a tired eye invents a hood. Thick matting after a muddy garden session can defeat the whole search, so brush the underside out first, in a separate calm session if needed, rather than combining grooming battles with anatomy homework.
Settling it at the first big appointment
Ask the veterinarian to confirm your Saint Bernard's sex during the first puppy visit if the coat and bulk leave you in doubt, and book sooner for any discharge, swelling, persistent wetness, or straining around the openings. Those signs outweigh the identification question at any breed size. Once the sex is certain, recording it on the KinsLe Pet Pass means this giant puppy's verified identity card states the correct details from the very start of its life with you.