The typical Shiba answer is no
Ask Shiba owners and a pattern emerges quickly: this is a breed that walks around puddles, objects to rain walks, and treats bath time as a personal insult. Swimming sits at the far end of that scale. Nothing in the Shiba's history selected for water work — he was a mountain hunting dog, valued for agility on land and an almost feline self-possession. Combined with a temperament that dislikes being manhandled or surprised, being placed in deep water is, for most Shibas, an experience to escape from and remember, which is why a forced first swim so often becomes a permanent refusal.
Why the coat argues against it too
A Shiba's dense double coat, so useful in snow, works against him in a lake. The undercoat absorbs water and holds it, making the dog heavy and uncomfortable while swimming and leaving him damp for hours afterwards despite towelling. A soaked Shiba who then stands in a breeze chills far more than his winter reputation suggests. Wet undercoat that is repeatedly left to dry slowly can also develop a musty, irritated skin environment under all that density, so a Shiba who does swim needs rinsing in clean water and thorough drying right through to the skin, not just a shake and a towel over the top.
If you want to try: the Shiba-respecting method
Work at the speed this breed accepts, which means he chooses every step. Start at a gently shelving shore or a shallow paddling pool on a warm day, walk in yourself, and let him investigate the edge with an easy exit behind him. Reward voluntary paw-wetting and brief wades; end while he is still relaxed, even if that is thirty seconds on the first day. A well-fitted dog life jacket helps a learner by keeping his body level, since a nervous dog paddles vertically and tires fast. Never carry a Shiba into deep water, never toss him in to discover he can swim — he can, instinctively, but the lesson he learns is that water and people near it are not to be trusted.
Safety for a dog who avoids water
A reluctant swimmer is at more risk around water, not less, precisely because he never practises. Secure garden ponds, keep him leashed near steep riverbanks and reservoir edges where a slip means deep water with no exit shelf, and watch him around boats and docks rather than assuming his caution keeps him safe — a startled dog can fall as easily as a bold one jumps. If a Shiba does go in unexpectedly, rinse and dry that coat fully, and contact your veterinarian if he coughs persistently after inhaling water, seems unusually tired or quiet later that day, or shivers that warming does not settle.
Sharing his profile before an outing
The riskiest moment for a water-averse Shiba is usually a cheerful outing with people who do not know him — a cousin at a lake house, a friend offering to take him to the beach. Tell them plainly, before they set off: he is not a swimmer, he wears a jacket near deep water, and he must never be thrown in. Before a day out, a relative can view his profile through Family Sharing in KinsLe, once you have given the relatives you pick access to it, and see the dog they are taking along.