<[i]My question is whether you treat dogs for lipoma
prevention since they can regrow new ones.[/i]
Lipomas in dogs are merely another localized lesion (like any skin symptom, e.g. a hotspot). They are always an expression of the Vital Force. Virtually all dogs of certain breeds (like Bichons, Poodles, terriers of all variety) will get them as they age (usually by middle age).
Localized lesions *always* act as an external vent for the internal energetic imbalance (which is what caused the lipoma in the first place of course).
Personally I *virtually never* recommend lipoma removal as it predisposes to other problems and tumors. In over twenty years I only remember seeing one or two that HAD to be removed (because they were being abraded and bleeding).
Treating the internal energetic imbalance that causes all symptoms (including lipomas) will help both existing lipomas and minimize occurrence of others.