Make sure you have a very secure area for potty. Never let her outside without you. I have seen them back up to a fence for a male, male climb the fence, etc. You know men, they want what they want. LOL Have something washable for her to lay on. If she gets in the bed or on the couch, a waterproof mattress pad to save the furniture/bed clothes is a good idea. Diapers do not work for us, someone will help Snookums get it off. Old rugs you can throw away might be a good idea too. Females are usually really clean about this but still you are talking about a big dog and there will be some mess. We are going on third heat here. I got sick and don't think we are going to make it to the spay before the heat. It really isn't that bad, just guard her around males. She may be more temperamental around other females/pets, clingie with her humans, or not eat as much. PMS in dog. One week coming in, light to heavy spotting, one week in heavy to light spotting, one week going out light to clear. Breeding usually 12th to 18th day after starting heat. So be really careful then. Hope this is what you wanted to know.