Here's why you should consider drafting a dog walking contract, what you should include in it and how to make it happen. The size and limit for group walks; How you'll handle dog waste or behavior issues; Payment terms, amount, and frequency.Veterinary Claim form or the Wag! Dog Walking and Pet Sitting Policies. Payment Invoices are billed the Friday before or seven days in advance of services being provided. CD bills the customer a lump sum amount for the training and boarding, including feed for the dogs. Those services are exempt in Washington. Dog walking services are also exempt in Texas and Wisconsin. Many dog owners in Washington rely on mobile apps such as Wag! Or Rover to help care for their animals.