Written by Staff Veterinarian
Our pets are just as vulnerable to sunlight-induced skin disease as we are. Some pets worship the sun as much as their beach-going humans do. In people, addiction to tanning is associated with the production of endorphins produced as part of the skin’s immune response to light exposure. Similar sun-seeking behavior can happen in pets as well. Although hair protects many animals from sunlight, not all parts of the body are covered with sufficient hair to shield the underlying skin from solar damage.
The armpits, abdomen, skin in front of the ears, nose and muzzle are vulnerable in all pets; short-coated breeds and lighter pigmented individuals are particularly at risk. Even indoor-only pets can have problems with too much sun. Although double-paned and newer glass windows can prevent most harmful effects of the sun, older glass windows do not block all types of potentially damaging solar radiation.
Too much sun can cause problems ranging from burns to cancer. Dogs and cats can get precancerous lesions called actinic keratoses, which can then progress to skin cancers such as squamous cell or basal cell carcinoma. Some dogs can develop tumors of the blood vessels called hemangiomas.
The best protection strategy in humans and animals is avoidance of the sun, particularly when radiation levels are the highest, between 10 AM and 4 PM. Early morning and evening are the safest times for long walks or outdoor play. A penned enclosure with shade cloth can be effective in treeless yards.
Some companies make “sunwear” for dogs, designed for solar protection. Human clothing can be adapted for our pets as well, although few dogs or cats tolerate hats.
Sunscreen use in humans has increased along with awareness of the damaging effects of too much sun. However, sunscreen is typically not applied appropriately or at high enough frequency to be effective. The use of sunscreens may impart a false sense of security, leading people to spend more time in the sun at the most dangerous times of the day. Veterinary sunscreens are available; human zinc-free sunscreens designed for use in infants can be alternative.