The Risk Of Solar Dermatitis In Pets
Sunbathing is fun, but taking too much can be dangerous. The skin reaction to excessive exposure to sunlight is called solar dermatitis. In domestic animals, the intensity of the skin lesions caused will depend on the exposure time, weather conditions, latitude and degree of pigmentation of the animal’s skin.
Like people, pets love being in the sun. However, owners need to be aware of the damage caused by sunburn and know how to prevent them. In this article we talk about the risk of solar dermatitis in pets.
Why does the sun hurt?
Before talking about the damage, it should be noted that exposure to the sun at the right time has beneficial effects for pets. On the other hand, it is important to know that, in addition to visible light, the solar spectrum contains infrared (IR) and ultraviolet (UV) rays.
A key fact to keep in mind is that the harmful effects of UV radiation are cumulative. For this reason, prolonged and repeated sun damage leads to progressively more serious effects.
On the other hand, the presence of melanin, the pigment that makes the skin dark, absorbs up to 45% of UV rays, so in a certain way it helps prevent sun damage. But melanin is not enough.
Solar dermatitis causes significant cell damage
UV rays have been shown to cause oxidative damage to cell membranes, DNA mutations and alterations in structural protein synthesis. As a result, an inflammatory reaction and abnormal activation of the skin cells are triggered.
At first, the skin becomes rough and red, but then the damaged tissue fills with spots. If damage occurs repeatedly, lesions can develop and progress to skin cancer. Gradually, they can lead to the appearance of invasive squamous cell carcinoma that spreads to the lymph nodes.
How to recognize solar dermatitis
Unfortunately, solar dermatitis sometimes resembles other skin conditions, such as allergies or pyoderma. For this reason, it is common not to recognize lesions until irreversible damage or skin cancer has developed.
Although cats and dogs tend to lick any injured areas, the itching or discomfort associated with solar dermatitis is generally minimal, unlike allergic dermatitis. It is also possible that the skin suffers at the same time from a sun dermatitis and an allergy.
In solar dermatitis, the coat becomes uneven and the underlying skin appears red and irritated. If the animal has patches of white and dark hair, in the dark areas the hair is normal without the loss of uneven hair and the underlying skin does not appear inflamed. By running his fingers over the skin, the owner can feel the difference in texture, as the colored fur protects better from the sun.
The lesions appear on some specific areas
Sun damage generally occurs in non-pigmented areas of fine hair such as the flank, belly, groin and axillary areas, ears, and nose. However, it may also appear on other areas. In pets that prefer to lie on one side of the body, the injuries can be worse on the more exposed side.
How solar dermatitis progresses
Solar dermatitis on the dermis of the animal progresses as follows:
- The first signs of sun dermatitis are inflamed red lesions, which can be felt to the touch.
- If the skin suffers repeated sunburn, folliculitis occurs, that is, lesions of the hair follicles from which the hair grows, hence the name. The injuries can be minor if they are superficial or more serious if they are deep.
- With chronic sun exposure, damaged areas thicken and patches appear with blackheads, erosions, ulcers, scabs, and drainage routes. Secondary bacterial infection or pyoderma are also common.
- This can occur in sun-induced skin cancers, such as squamous cell carcinoma, cutaneous hemangioma, and hemangiosarcoma.
Which animals are most at risk?
Solar dermatitis is a common ailment in pets that live or spend the summer in warm, sunny climates. It can also affect animals that live at high altitudes or spend a lot of time outdoors, even in temperate areas.
In general, dogs and cats who suffer from diseases or genetic defects that cause alopecia or thinning of the fur are more at risk. This is the case for those suffering from flea infestation or fungal infections.
Animals with chronic skin diseases, such as atopic dermatitis, are also vulnerable. Additionally, surgery that leaves certain areas of the skin exposed due to surgery causes sunburn, especially if unprotected.
Dogs with autoimmune diseases should be carefully monitored for sun exposure, otherwise existing conditions will worsen. The dog breeds most susceptible to sunburn include: Dogo Argentino, White Bulldog, White Boxer, Dalmatian, Beagle, and Greyhound.
Solar dermatitis diagnosis
In general, the diagnosis of dermatitis is established by the patient’s clinical signs and excluding other causes of dermatitis, such as fungal or bacterial infections. One reason for suspicion is when skin lesions do not improve with empiric therapy.
Skin biopsy and histological examination are the main tools for diagnosing non-healing solar dermatitis and sun-induced neoplasia. Secondary bacterial infection can develop, so your vet may choose antibiotics to administer for two to three weeks before performing the biopsy.
In these cases, it is essential to provide a complete history of the animal, including the degree of sun exposure, distribution of lesions, clinical description of lesions, response or lack of response to previous therapies.
It is also important to indicate current drug treatments (including glucocorticoids) that could affect histological findings. It is advisable to request a complete histological description and to ask for the interpretation of a veterinary dermatologist.
Treatment
Without a doubt, the best treatment for solar dermatitis in pets is prevention. Owners need to understand the need to avoid sun exposure from an early age. In fact, no oral or topical medication can substitute prevention for harmful sun exposure.
Recommendations for avoiding solar dermatitis in pets
The main recommendation is to limit sun exposure by keeping pets indoors between nine in the morning and three in the afternoon. If some sun exposure is unavoidable, topical application of a water resistant sunscreen with a high sun protection factor is recommended.
It is important not to use the same sunscreen used for humans, as they contain zinc oxide and para-aminobenzoic acid (PABA), which can be toxic if the animal licks itself. A dog sunscreen can be purchased at many specialized outlets.
As for cats, sunscreens that contain octisalate or acetylsalicylate, a substance similar to aspirin that can be toxic if ingested , should be avoided. Unfortunately, there are currently no sunscreens specifically formulated and safe for cats.
Dog sun clothes and even a t-shirt are better than nothing. You could make holes for the legs so that the belly and back are well covered. Unfortunately, however, this will leave the legs vulnerable.
As we can see, solar dermatitis is a difficult disease to diagnose and cure once it occurs. Therefore, prevention will always be the best ally to avoid this type of skin problems in pets.
