There are two types of seborrhoea which are both common in the dog.
1: Seborrhoea sicca is the dry form of seborrhoea. In this skin disorder there is an overproduction of skin cells. This results in large numbers of skin cells being shed which gives rise to dandruff (scale). This problem causes itchiness of the skin and the dog may nibble and scratch itself excessively. This leads to further trauma to the skin and possibly secondary bacterial or fungal infections. The coat of animals suffering from seborrhoea sicca looks dull and there is a copious amount of dandruff.
2: Seborrhoea oleosa is the oily form of seborrhoea. In this disorder there is an excessive production of sebum (the oily substance produced to keep the skin moist and healthy). The skin and coat become very greasy, often with excessive dandruff around the base of hair shafts and matted fur. This skin disorder may cause the dog to have an unpleasant odour. It is an irritating condition for the dog and there may be secondary problems such as hair loss and bacterial infections due to constant self trauma from nibbling or scratching.
Seborrhoea in dogs may be primary (idiopathic) or secondary to other diseases.
Idiopathic seborrhoea is a chronic disease affecting certain breeds of dog. The cause of this type of seborrhoea is unknown but some breeds of dog are genetically predisposed to primary seborrhoea. Breeds affected in this way include Cocker spaniels, German Shepherds, West Highland White Terriers, Bassett Hounds, Dachshunds, Doberman Pinschers, Irish Setters, Labrador Retreivers, Poodles and Springer Spaniels.
Seborrhoea may sometimes be secondary to other skin diseases. Any skin disorder which causes chronic inflammation of the skin may lead to seborrhoea. The list of skin diseases which may lead to seborrhoea is extensive and may include; allergies to fleas/food/other environmental pathogens, endocrine diseases (many of which affect the skin), parasitic infections of the skin such as fleas, demodectic or sarcopotic mange, harvest mites or Cheyletiella, bacterial infections of the skin (pyoderma), fungal diseases of the skin commonlyMalassezia and dietary deficiencies of zinc, protein or vitamin A.
To treat seborrhoea it is first necessary to eliminate any underlying skin conditions which may be causing it. If there is an infection of the skin with bacteria, fungi or yeasts then this must be treated first. If there are areas of the skin which are angry and inflammed or if there is a foul smell to the skin then there are likely to be pathogenic bacteria present. It may be necessary to treat your pet with antibiotics if there is a secondary bacterial infection of the skin. Occasionally other drugs such as steroids will be required to treat your pet effectively.
Cases of idiopathic seborrhoea and the early or mild cases of secondary seborrhoea may be treated with shampoos or oral food supplements. The aims of treatment are to eliminate any causative factors and then reduce inflammation of the skin whilst normalising the production of skin cells and sebum.
If your dog suffers from seborrhoea (especially if the underlying cause is believed to be atopy) then dietary supplementation with essential fatty acids may help. Essential fatty acids such as gamma linolenic acid (GLA) cannot be produced by the body and must therefore come from the diet. They are necessary to maintain healthy skin. Essential fatty acids such as GLA are found in oil of evening primrose or starflower oil, as well as certain fish oils. These oils may be beneficial in the treatment of seborrhoea. Essential fatty acids such as gamma linolenic acid (GLA) help to maintain healthy skin by regulating inflammatory pathways, skin prostaglandin hormone production and the production of sebum. I often use a product called Viacutan which is specially formulated for animals and contains high levels of GLA in a bioavailable form. It is made from a combination of plant and fish oils. Animals like it because it is very palatable and it is packaged in such a way that it does not oxidize when the package is opened as many such products do.
Shampoos are very useful in the treatment of seborrhoea in dogs. At first the dog may need to be bathed every second day but take care not to bath too much as this can make the problem worse by drying the skin excessively. The type of shampoo which should be used depends upon the type of seborrhoea to be treated. For oily seborrhoea I would use Sebolytic shampoo containing coal tar to degrease the skin, reduce skin scaling and sebum production and reduce inflammation. For dry seborrhoea Sebomild shampoo is usually very effective if there is no underlying cause remaining untreated. If there is a secondary bacterial infection which requires treatment then a shampoo called Etiderm (contains ethyl lactate) may be used following the Sebomild or Sebolytic to reduce bacteria on the skin. Of course antibiotic treatment may also be required. Some vets use shampoos containing selenium sulphide (Seleen) or benzoyl peroxide (Paxcutol) to treat dogs with seborrhoea but I believe these products are much too harsh and drying for the skin.
To help prevent seborrhoea in dogs which are prone to it there is a shampoo called Sebocalm which may be useful. It is formulated for frequent use and I would suggest washing your dog weekly with it. Sebocalm is gentle and moisturising on the skin. If you wash your dog with a shampoo such as this and use a preparation containing essential fatty acids as a dietary supplement you may be able to prevent the recurrence of seborrhoeic dermatitis.
Unfortunately it is difficult to completely cure primary seborrhoea. It is best to assume that the problem will recur from time to time and aim to control it. Secondary seborrhoea may be treated effectively if the underlying cause can be determined and eliminated.