Which dogs a slatmill suits
A mill is a supplement to real exercise, not a replacement for it. It earns its place with dogs whose needs outrun what a walk provides.
Sled and mushing breeds
Huskies, malamutes and similar breeds are built for sustained work and are often difficult to condition in the off-season. Mills are long established in mushing for exactly this reason.
Working and sport dogs
Dogs in protection sports, weight pull and similar disciplines need conditioning that a walk does not provide, and mills give a controlled way to add it.
High-energy companions
Some working-bred dogs in pet homes genuinely cannot be tired by ordinary walking. A mill can take the edge off, though it does not meet the mental exercise those dogs also need.
Weather and space
Extreme heat, ice or short winter days limit outdoor conditioning. A mill in a garage keeps a routine going without changing it every season.
Dogs it does not suit
Puppies and adolescents still growing, brachycephalic breeds that struggle to cool, elderly dogs, and any dog with an unresolved orthopaedic problem.