Solar Dermatitis in Dogs

Key Takeaways

Solar dermatitis is a condition caused by exposure to UV rays, which leads to irritated skin, rashes, and potentially cancerous growths. 

• Solar dermatitis is not usually an emergency

• If caught early, reducing exposure to the sun is usually sufficient to treat the condition

• Severe cases can lead to skin cancers which are potentially life-threatening

• The presence of skin lesions suggests the diagnosis and biopsies confirm it

• In addition to avoiding UV exposure, antibiotics, topical steroids, anti-inflammatories, and topical vitamin A are the most common treatments for solar dermatitis

• Surgery becomes necessary if tumors develop

• Prognosis is variable, depending on the intensity of the skin’s irritation and whether the condition has become cancerous

A Closer Look: What is Solar Dermatitis in Dogs?

This condition frequently occurs on the dorsal part of a dog’s muzzle. In these cases, irritation of the skin presents around the front or bridge of the dog’s nose, and sometimes about their eyes. If caught early, solar dermatitis is not an emergency. When a dog’s skin first begins to turn red or appears irritated after prolonged sun exposure, reducing UV exposure often leads to resolution of the symptoms. 

Solar dermatitis can lead to skin cancers if early signs are ignored. If the skin oozes, bleeds, or growths begin to develop, then veterinary assistance is required. If the skin is red and irritated but does not seem to improve with reduced sun exposure, veterinary attention is helpful for determining the underlying cause. Many skin conditions present with similar symptoms.

Risk Factors

Most healthy dogs don’t develop symptoms as a result of exposure to UV radiation because: 

• They’re not exposed often enough or long enough

• Their fur provides protection

• Pigment on their skin (particularly the nose, lips, and eyelids) provides protection

Early symptoms include irritated skin, hair loss, and minor skin lesions. If the affected dog has both fair and dark pigmented fur, the skin under the darker fur will rarely exhibit symptoms, as darkly pigmented fur better protects from the sun. Dogs with short, fair hair are at higher risk of solar dermatitis. Any exposed areas of skin, such as those found on hairless breeds or shaved areas after surgery are also at higher risk.

If repeated sun exposure continues, the symptoms will visibly worsen. Obvious ulcers and cysts develop. Affected skin appears red and may develop pimples or blister-like lesions that ooze or bleed.

Possible Causes

Solar dermatitis is caused by repeated, chronic exposure to harmful ultraviolet radiation from sunlight (or other sources). This radiation damages skin cells, leading to tissue damage and cell destruction. Radiation can also cause damage to cells that may lead to skin cancer.

Main Symptoms

The main symptoms of solar dermatitis are:

• Irritated, red skin • Hair loss • Cysts, blisters, or ulcers on the skin

Testing and Diagnosis

Diagnostics for symptoms of solar dermatitis include: 

• Physical exam • Skin cytology • Skin biopsy • Blood work • Diagnostic imaging

Steps to Recovery

Treatment for solar dermatitis includes: 

• Reducing UV exposure • Topical steroids • Topical Vitamin A • Surgical removal of tumors

• Antibiotics for secondary infections

This condition lasts longer when exposure to UV radiation is ongoing. When exposure to UV radiation is reduced or eliminated, mild, non-cancerous symptoms usually resolve within a week. Although symptoms can improve with treatment, the skin must be monitored carefully for changes in the following months, as tumors can develop even after symptoms have faded. The prognosis of cancerous solar dermatitis also varies, depending on the type, location, and number of the tumors.

Prevention

The best way to prevent solar dermatitis is to keep at-risk dogs out of the sun, particularly during mid-day when the UV index is highest. Sunscreen specifically designed for pets can also be used to prevent solar dermatitis. Sunscreen must be applied liberally and repeatedly to be effective, and it doesn’t work if it’s licked off. Sunscreens meant for humans are not safe for use on pets. Always consult with a veterinarian before using topical products on animals.

Is Solar Dermatitis Common in Dogs?

Solar dermatitis is most common in dogs with fair or short hair, as neither protects from UV radiation well. It is much less common in dogs with darker or longer hair. It is more common in dogs who spend a lot of time outdoors, particularly in high elevations where UV radiation is stronger.

Typical Treatment

• Reduced sun exposure • Vitamin therapy • Anti-inflammatories • Topical steroids

• Surgical intervention