Strictly speaking, seborrhea is not a disease but a phenomenon that occurs after skin pathology. Seborrhea is a common skin condition (including in humans) characterized mainly by extremely oily fur that emits a rancid oily smell, similar to spoiled cooking oil. No matter how much it is washed or brushed, the skin and hair remain clumped and have an unpleasant oily odor.
Usually, seborrhea symptoms also include flakes of skin falling off in patches, which may occur all over the body or just in localized areas. If not treated for the underlying cause, when bacteria on the oily layer invade the skin and hair, it easily leads to deeper follicular damage, known as seborrheic dermatitis.
Many factors can trigger seborrhea. Inflammation of the superficial skin is very common. Excessive grooming or washing damages the protective layer of the skin and fur, making the condition more likely. Additionally, follicular mites, lice infections, or fungal skin infections can also cause inflammatory seborrhea. Early-stage cutaneous lymphoma is another cause of inflammatory seborrhea.
In many small animals, endocrine problems can also trigger seborrhea. The most common are hypothyroidism and hyperadrenocorticism (known medically as CUSHING SYNDROME). Hyperadrenocorticism can be spontaneous or iatrogenic. Spontaneous cases are rare in clinics, but iatrogenic hyperadrenocorticism is common.
So, what is iatrogenic hyperadrenocorticism? It usually arises when steroids are overused or improperly used during treatment, often unknowingly through nutritional or anti-inflammatory injections that contain steroids. Besides symptoms of hyperadrenocorticism, seborrhea can also develop. However, not all small animals with hypothyroidism or hyperadrenocorticism necessarily have seborrhea.
Seborrhea also occurs in humans, but it is not contagious between humans and animals. When humans have active endocrine function and oil secretion, combined with poor personal hygiene, seborrhea can appear on the scalp, armpits, and private areas. However, humans usually mask this condition through clothing, perfume, or washing to conceal odors.
Many nutritional deficiencies can also induce seborrhea. Deficiencies in glucose, proteins, fatty acids, vitamins, and trace minerals—all essential for skin cell metabolism—are common causes. These deficiencies generally stem from unbalanced diets, but continuous feeding of dry kibble to dogs and cats usually prevents these deficiencies.
The skin's surface environment also influences seborrhea. Rapid loss of moisture, excessively humid climate, frequent bathing (especially with irritating shampoos), and fatty acid deficiency can change the skin's surface environment, promoting seborrhea.
Treatment depends on the cause. For simple seborrhea, shampoos containing salicylic acid are suitable, and shampoos with BENZOYL PEROXIDE are also good choices. However, benzoyl peroxide shampoos deeply clean the skin and can cause irritation, so they must be thoroughly rinsed off and not overused.
If seborrhea results from endocrine or other factors, veterinary diagnosis is necessary to treat the underlying cause. Seborrheic dermatitis is not a disease itself but a result of other diseases. Therefore, treatment focuses on the root cause, combined with medications to relieve seborrheic dermatitis symptoms.
