You should generally bathe your dog at least once every three months to prevent dirt, grease, and bacteria buildup that could lead to skin problems. However, the exact frequency depends on several factors including breed, coat type, activity level, and skin condition. Short-haired dogs with healthy skin may only need baths every two to three months, while long-haired or double- coated breeds may need more frequent brushing and less frequent bathing to avoid drying out their skin. Hairless or oily-coated breeds might require weekly or more frequent baths to maintain skin health. Active dogs that get dirty or smelly more often may also need baths every two to four weeks. It's important not to bathe too frequently, as overwashing strips natural oils, causing dryness and irritation. Special shampoos may be needed for dogs with skin issues, and your vet can advise on that. Overall, bathing should be driven by cleanliness, odor, and the dog's lifestyle.