Under the coat, spacing still rules
A young Collie is male if a raised rounded opening sits along his belly, and female if the only genital opening is a slit tucked under her tail. The Rough Collie's glamorous outline, all mane and sweeping skirt, makes this breed one of the easiest to misjudge from a standing view, because what you are reading is coat architecture rather than anatomy. Sweet expression, sable shading, and a gentle nature appear equally in both sexes of this famously sensitive breed. Roll the puppy gently over in your lap and work down to skin level, where the honest answer is waiting.
Combing your way to a clear view
Choose a quiet moment after a meal, settle your young Collie across your knees on a rug, and let the puppy get comfortable before you touch the belly. Use a wide comb or your fingers to sweep the long underside hair to each side, creating a parting from chest to tail that you hold open with one hand. Collies feel handling keenly, so move slowly, speak softly, and pause if the puppy tenses or tries to right itself. A second person stroking the head end usually keeps a young Collie relaxed enough for the half-minute this inspection needs.
Recognising a male Collie puppy
On a male Collie, the parted belly hair reveals a small hooded bump with a tiny central opening, set roughly midway between the navel area and the hind legs. Its raised profile is what matters, because the surrounding coat tries to flatten everything into one smooth white expanse. Toward the rear, between his back legs, two small testicles may be present as soft ovals under the skin in an older puppy, or barely suggested in a younger one. The unmistakable point remains the geography: his genital opening lives on the belly, separated from his anus by a clear stretch.
Recognising a female Collie puppy
On a female Collie, the parted belly shows a smooth surface broken only by the flat little scar where her cord healed, no matter how thoroughly you comb the hair aside. Her genital opening sits beneath her tail, a small vertical slit positioned just below her anus and often half-hidden by the plume of tail hair sweeping over it. Brush that tail feathering upward and use good light, because white belly hair reflects glare that can wash out the detail. If the under-tail slit is the only opening you can find, your Collie puppy is female.
Collie-specific sources of confusion
That splendid coat is the chief confounder in a young Collie, folding over a male's prepuce or casting a shadow that invents one on a female. The navel scar is the second trap, sitting flatter and higher than a true male opening but catching the eye of anyone scanning quickly. Behaviour misleads as well, since sensitive male Collies may seem dainty and reserved while confident females boss their littermates. Trust only the parted-coat anatomy check, repeated in daylight if your first attempt happened under lamplight on a sleepy evening.
Confirming the result for the record
Have the veterinarian confirm your Collie's sex at the first puppy visit if the coat defeated your home attempts, and seek an earlier appointment for any discharge, swelling, matting with soreness under the tail, or difficulty passing urine. Matted under-tail hair deserves a gentle trim by a groomer or vet rather than home scissors near delicate skin. With the sex settled, entering it on the KinsLe Pet Pass gives this Collie a verified identity card that presents the right details whenever you show it.