How would you go about asking an owner to groom their dog before you sit them?
We have one client whose dog is a huge sweetheart, and incredibly stinky. We like sitting her a lot, but the smell is so bad we have to keep her separated and out of the main living area. We'd like to continue sitting her, but unless she does something about that smell I don't think we can.
I think the best way is to discuss when you're discussing next arrival. Something along the lines of we're looking forward to having sweetheart Rover return this Friday at noon. Will she be washed prior to arrival or would you like us to prepare to bathe her while she's here?
If the client wants you to bathe her sweetheart, then you can adjust the price quote to reflect that service if you do it yourself or opt to take her to a dog bath station area. If you're going to do it yourself, ask the client to include her brush/comb, shampoo, and such. If you get a professional groom, you may ask if she can reimburse you based on the receipt upon pick up, so a percentage isn't deducted by Rover.