Just like humans, pets can get sunburned.  Light-colored dogs and cats especially are susceptible to sunburn and can develop skin cancer.  To protect your pet:  Several companies, including Doggles, sell sunscreen for pets (Cost:  $9.95 for a two-ounce SPF-15 spray. www.doggles.com)  Apply sunscreen once a day (or more frequently, depending on the amount of time spent outside) to areas with sparse hair, such as the nose, ears and stomach.