Does your dog have a pink nose or ears, or patches of white hair? If so, you need know about the risk posed by sun damage.
It isn’t just people who get burned by the sun — dogs do too.
However, a lot of folks (including some vets) don’t recognize sun damage in dogs for what it is. Hence, dogs suffering from “solar dermatitis” (or sunburn) may be misdiagnosed as having allergies or a skin infection.
But more than the inconvenience of a mistake, solar dermatitis could have serious consequences and become cancerous. These serious cancers include:
How Sun Damage Happens
UVB burns the skin, which is the first step toward more serious problems. But Mother Nature knows this and has her own built-in sunblock. For our 4-legged friends, this takes 2 forms: fur and pigment.
A long-haired dog wears the equivalent of a UVB-resistant fur suit. That fur stops the sun’s rays from penetrating down to the skin. This is also a strong argument for not shaving your pet because this natural protection is then removed.
Mother Nature’s other strategy is pigment, or, more precisely, melanin. This dark pigment absorbs the UV rays and stops them from penetrating into the deeper layers of the skin. (For the trivia lovers among you, yes, those dark patches dogs have get physically warmer than the white bits. So a spotty dog like a Dalmatian has literally hotter spots.)
Progressive exposure to UVB damages the skin cells and causes naturally occurring toxic chemicals (cytokines, or “cell killers”) to leak into the area. Over time, this causes the cells to mutate in the process we know as cancer.
Dogs Who Are Most at Risk
Any dog can suffer sun damage if they stay outside long enough, while some are more at risk than others.
The dogs who lack melanin top the “at risk” list. These guys are easy to spot because they have pink skin (noses and ear edges) or patches of white fur:
If your dog is short-coated, even places such as the trunk or legs that have fur are at risk. It’s all a matter of how long they spend outside and how fierce the sun is.
With this in mind, it isn’t just dogs in hot climates who need to be careful. Those who live at high altitudes, where the atmosphere is thinner and the UVB penetrates more readily, are also at risk — as are dogs who spend lots of time outside, especially between 10 a.m. and 4 p.m., when the sun is at its strongest.
Signs of Sunburn
Early sunburn is marked by reddened and inflamed skin that is tender to the touch. This is often painful, which causes the dog to lick it. So if your dog’s skin suddenly seems irritated after spending time in the sun, be suspicious of sunburn.
A top tip for deciding if this is sunburn, parasites or an infection is to check the dog’s darker patches (if they have any). In spotty dogs such as Dalmatians, a tell-tale sign is a clear border of inflammation where the white furred skin stops looking sore where it meets the brown (protected) patches.
In the longer term, repeated sun exposure triggers other changes in the skin:
Sadly, it’s only a hop, skip, and a jump from here to cancerous change.
Sun damage skin cancers are often erosive and ulcerative — which means they break open, weep and look incredibly sore and angry.
Watch this news item on sunscreen for dogs:
Prevention Is Better Than Cure
Be aware of the risks, and use simple strategies such as keeping your dog indoors during hours of strong sun exposure in the height of the summer.
In addition, use doggie sunscreen all over the dog, not just on noses and ears. Choose a pet-safe formulation, preferably in a spray form. Simply mist it all over the dog and then distract them with a toy while it dries. Reapply after swimming or every 4–6 hours, whichever is sooner.
Never use human sunscreen unless it is zinc oxide-free. Zinc is toxic to dogs when taken internally — they may lick the sunscreen off. Obviously, this isn’t a problem with people, as we don’t tend to lick ourselves.
Whether 2- or 4-legged, use sunscreen and enjoy the good weather without tears, either today or further down the line.
This pet health content was written by a veterinarian, Dr. Pippa Elliott, BVMS, MRCVS. It was last reviewed July 14, 2017.