Medically reviewed by: Kinga Wojtczak, Doctor of Veterinary Medicine, specialist in canine and feline diseases
A beautiful, shiny and smooth dog coat is the dream of many owners. Very often, however, despite using various care products, owners report a problem with a greasy coat—after petting or playing, a residue is noticeable on the hands, the dog's skin smells unpleasant, and the hairs stick together in unsightly, greasy clumps.
These are the signs of seborrhea. In the article below, I will try to describe this clinical sign.
Table of contents:
What is seborrhea?
First, it is important to note that oily (greasy) seborrhea can be primary or secondary. Both types produce similar lesions, but the treatment approach is different. Seborrhea can also take a dry form. Dry seborrhea is commonly called dandruff in dogs, and you can read about it in this article: https://cowsierscipiszczy.pl/lupiez-u-psa/
Secondary oily seborrhea is more of a clinical sign of other diseases, such as:
- ringworm (dermatophytosis),
- leishmaniasis,
- pyoderma (bacterial skin infection),
- allergies (food allergy, atopy).
It may indicate hormonal disorders and appear, for example, in dogs with hypothyroidism, hyperadrenocorticism (Cushing's disease) and diabetes mellitus. It is also seen in many immune-mediated diseases, such as:
Its presence may also point to an external parasite infestation. Animals suffering from nutritional deficiencies, including deficiencies of zinc and vitamin A, are also predisposed to secondary seborrhea.
As for primary oily seborrhea, it is caused by a congenital, inherited disorder of epidermal keratinization and by overactivity of the sebaceous glands. The breeds predisposed to the condition are:
No sex predisposition has been observed for this condition. The first lesions may be seen in very young animals, but the disease often becomes apparent when the dog's immunity is weakened or when another illness develops that worsens the dog's general health. Seborrhea is especially common between the toes and on the face, perineum, neck and armpits. All skin folds on the pet's body are prone to seborrhea.
Seborrhea in dogs: clinical signs
Animals affected by this condition have a dry, brittle coat that lacks shine, is often ruffled and difficult to style. The hairs may be stuck together in clumps, and they may become matted and discolored. They are very easy to pull out. The whole coat seems to be covered with a sticky residue that you notice after stroking the pet. In addition, the dog has a characteristic smell, like rancid fat.
When the coat is parted, large amounts of scale (dandruff) are visible on the skin. Sometimes a brownish film may also be seen on the skin. In some places there may be hairless patches of excessive scaling and keratinization of the skin, with lesions resembling dry crusts that lift easily off the skin. The lesions may be itchy—scratching them increases keratinization, and oozing (exudate) or secondary bacterial infections may develop.
Skin affected by seborrhea is very susceptible to infections caused by opportunistic microorganisms. Very often, dogs suffering from keratinization disorders also have localized or generalized skin infections caused by yeasts of the genus Malassezia, ear canal infections and excessive earwax production.
Diagnosing seborrhea in dogs
The lesions seen on physical examination are fairly characteristic. However, it must be determined whether the seborrhea is a primary condition or is caused by other diseases. To do this, it is a good idea to run a basic blood test, including thyroid hormone levels. It is also essential to use proper external parasite prevention with a broad-spectrum product—skin parasites do not always show up on a skin scraping.
If the diagnosis is unclear, a skin scraping from the most affected areas is worthwhile. The sample will mainly show very large numbers of exfoliated skin cells. Many of them will show signs of defective keratinization. Under the microscope, the hairs will have lifted scales, they may be broken, and follicular casts will be visible around them.
Seborrhea in dogs: treatment
Treatment of seborrhea should include ruling out the possible causes (listed above) and, in addition, topical and systemic therapy. For systemic therapy, a good place to start is choosing the right dog food. Ideally it should be a hypoallergenic diet rich in polyunsaturated fatty acids, vitamins A and E, zinc and selenium. It is also a good idea to give fatty acids and vitamin A daily as dietary supplements for dogs.
Topical therapy should include baths with antiseborrheic shampoos. The ideal antiseborrheic shampoo should contain keratolytic and keratoplastic (keratoregulating) compounds. These are sulfur, selenium, tar and salicylic acid. Benzoyl peroxide, used as a shampoo additive, helps to clean the openings of the sebaceous glands.
How the bath is given also matters—after an initial wash, the product should be applied thoroughly and left on the skin for 10–15 minutes so that its active ingredients can work. Appropriate emollients are essential to keep the skin properly moisturized, especially after bathing—the ingredients listed above can dry out the skin.
Baths should be given as often as every 2–5 days, depending on the condition of the dog's skin, and as treatment progresses, the intervals between them can be extended. Remember to prevent and treat possible complications related to the weakened skin. The pet should be checked regularly for secondary bacterial infections, especially where the skin is damaged. It is essential to keep up ear hygiene by cleaning the ears—daily or every few days, depending on their condition and how much earwax is produced (of course using an ear cleaning solution that is poured into the ear canal; never use cotton swabs to clean the ears!).
Pay particular attention to hygiene in the areas prone to seborrheic lesions. In very advanced cases, where seborrhea occurs with generalized itching and skin hyperesthesia, antipruritic therapy should be considered. Just a few years ago, starting corticosteroids promptly was recommended once seborrhea appeared; today they are used only in exceptional cases. In extreme cases, therapy with retinoids and calcitriol is also considered.
Prognosis
The prognosis depends on the cause of the seborrhea. In secondary seborrhea, once the underlying cause has been brought under control, the prognosis is fairly favorable. Of course, the condition of the pet's coat should be checked regularly to prevent the disease from coming back. In primary seborrhea, the prognosis is guarded. Dogs that have developed primary seborrhea should not be used for breeding.
Remember that a dog that has had a keratinization disorder once is predisposed to a recurrence. Therefore, if the skin improves after a diet change, it is a good idea to continue the therapeutic diet for several months after the signs have resolved. The dog's coat should be groomed and brushed regularly. You should also regularly use grooming products suitable for your pet.
FAQ
What are the symptoms of seborrhea in dogs?
Animals affected by this condition have a dry, brittle coat that lacks shine and is often ruffled, and the hairs can be stuck together, clumped and discolored. The whole coat seems to be covered with a sticky residue that you notice after stroking the pet, and the dog has a characteristic smell, like rancid fat. When the coat is parted, large amounts of scale (dandruff) are visible on the skin, sometimes with a brownish residue.
What causes seborrhea in dogs?
Secondary oily seborrhea is a clinical sign of other diseases, such as ringworm, leishmaniasis, pyoderma or allergies. It may indicate hormonal disorders and appear in dogs with hypothyroidism, hyperadrenocorticism (Cushing's disease) and diabetes mellitus, and its presence may also suggest an infestation with external parasites. Primary seborrhea is caused by a congenital, inherited disorder of epidermal keratinization and by overactivity of the sebaceous glands.
Which dog breeds are prone to seborrhea?
Breeds predisposed to primary oily seborrhea are American Cocker Spaniels, Basset Hounds and West Highland White Terriers. No sex predisposition has been observed for this condition. The first lesions may be seen in very young animals, but the disease often becomes apparent when the dog's immunity is weakened.
How is seborrhea in dogs treated?
Treatment involves ruling out possible causes, plus topical and systemic therapy. A good starting point is the right food—ideally a hypoallergenic diet with a high content of polyunsaturated fatty acids, vitamins A and E, zinc and selenium. Topically, baths with antiseborrheic shampoos containing sulfur, selenium, tar or salicylic acid are used; the product is left on the skin for 10–15 minutes, and baths are given as often as every 2–5 days.
Can seborrhea in dogs be cured?
The prognosis depends on the cause of the seborrhea. In secondary seborrhea, once the underlying cause has been brought under control, the prognosis is fairly favorable, whereas in primary seborrhea it is guarded. A dog that has had a keratinization disorder once is predisposed to a recurrence, so its coat should be groomed and brushed regularly.
