There is no single guideline to determine how frequently a dog should be bathed, but a good rule for most short-haired breeds is to wait until the dog is noticeably dirty. Breeds with longer hair or unusual coat texture may need to be bathed more often.
Bathing a dog too frequently can dry out the dog's skin and coat leading to irritation and damage to the hair. Regularly brushing the dog helps keep the coat healthy and clean, making baths less important. Consulting a professional dog groomer or a veterinarian can be useful in determining how often an individual dog needs to be bathed.