It will really seem like a long time, and have you wondering if they'll ever grow it back! In around 3 months, your Coonie may have the length of short-haired cats. Actually, this is the only time you'll ever see a 'short-haired Maine Coon!' It could take a year, or even years, though, for them to fully regain that glorious multi-length healthy coat that this breed is celebrated for.