Dear Dr. Barchas,
Brandi Kitchener, ON, Canada
Excessive sun can burn both dogs and cats. And, like people, both species can develop skin tumors from excessive sunning. Fortunately, most pets have a major defense against the sun that people lack: fur.
The risk your dog faces depends on her color, the length of her fur, and her lifestyle. Dogs with short light coats (like Dalmatians) are more likely to burn. So are dogs that live in sunnier climates and lead active, outdoorsy lifestyles. That said, the health benefits of an active lifestyle outweigh the risk of sunburn in most dogs.
Some dogs will develop a discolored area on the top of their nose if they spend too much time in the sun. The area can progress to a red ulcer that may require veterinary attention. These dogs should avoid being outdoors during peak sun hours in summer.
Cats with all-white faces may develop scabs around the ears, eyes, and nose. Over time, the scabs may turn into a type of skin tumor called squamous cell carcinoma. Exposure to the sun is not required for this to happen, but it definitely makes it more likely. Cats with all-white faces, as well as hairless cats such as Sphynxes, should not go outside during peak sun hours.
Some people apply sunscreen to high risk pets. This works best on the ears and head, where it can’t be licked off.
Finally, don’t panic if you catch your dog or cat sunning itself every now and then. Most pets can soak up quite a few rays before they run into trouble.