Dermatophilosis – when the skin suffers

Dermatophilosis, not to be confused with dermatomycosis caused by fungi, is a bacterial skin disease in horses. It occurs mainly in the wet and cold season in horses that are kept in open stables or spend a lot of time in pastures, which is why it is also colloquially referred to as rain eczema.

INHALT
Cause and origin Symptoms Diagnosis Therapy Forecast Prophylaxis
Cause and origin

The pathogen and namesake of this skin disease is the bacterium Dermatophilus congolensis, which does not harm horses with healthy skin and skin flora. Pathological skin changes only occur when the skin's natural protection is destroyed by metabolic disorders, small skin lesions, or prolonged moisture. Dirty, sweaty, or chafing saddle blankets can also cause severe skin irritation in the back area, which then becomes a gateway for the pathogen. The bacterium penetrates the upper layers of the skin through small cracks or softened skin and can multiply there in the absence of air. Transmission from animal to animal is extremely rare.

Symptoms

The first signs of the disease are usually isolated crusty, sticky, nodular thickening of the skin on the joints and back, which can spread rapidly over large areas if left untreated. The crusts stuck to the fur can be easily removed from the skin underneath. The affected areas of skin are warm, sore, and reddened, and are often covered with a greasy secretion. As the disease progresses, the crusts gradually peel off, leaving large areas of hairless skin. The inflamed skin is painful, and in severe cases, fever and fatigue may also occur.

Diagnosis

After a thorough general examination and a detailed preliminary report, the veterinarian will usually be able to make a tentative diagnosis based on the findings. With the help of a simple microscopic examination of specially stained samples taken from the affected skin areas, the diagnosis can often be confirmed and other causes ruled out, as the bacteria are very characteristic under the microscope.

In unclear cases or if symptoms have been present for a long time, the veterinarian may also take a skin scraping to culture the pathogen in the laboratory and use an antibiogram to determine which preparation is effective.

Therapy

Treatment depends on the extent and severity of the changes. In the early stages and if the condition is only mildly widespread, it can be successfully treated with mild local washing and antibiotic ointments or sprays. If large areas of the body are already affected and the horse is also showing general symptoms, a special antibiotic should be administered. Your veterinarian will discuss the required treatment with you in detail on a case-by-case basis.

Forecast

With early diagnosis and treatment, the prognosis for a full recovery is very good. In severe cases, hairless, bulging thickening may remain, primarily on the limbs after the damaged skin areas have healed.

Prophylaxis

There is currently no effective vaccine against dermatophilosis. The most effective measures for preventing the disease are therefore to avoid keeping the coat wet for long periods and to continuously control insects.