Diseases of Skin
Dermatitis is the inflammation of dermis and epidermis resulting in pain on palpation and erythema.
Etiology: The disease is caused by infection with dermatophyte, ringworm, mange, stephanofilaria or strongyloid. Burn, ß-radiation, chemical irritants or arsenic poisoning also results in dermatitis. In bovines, dermatitis is seen in cow pox, lympy skin disease, rinderpest, bovine malignant catarrah and bovine viral diarrhoea while in sheep, it occurs in strawberry-foot-rot, sheep pox, bluetongue, rinderpest and lumpy wool disease. In horses, it occurs in staphylococcal infection, vesicular stomatitis and dermatophytosis.
Pathogenesis: Infectious as well as noninfectious agents penetrate the deeper layers of skin and involve blood vessels and lymphatics to produce inflammation of dermis and epidermis.
Symptoms: There is edema of skin and subcutaneous tissue, erythema, development of discrete vesicular lesions, escape of fluid from these lesions, and pain sensation. Later on the lesions are healed up and scab formation occurs. In more severe cases, necrosis or gangrene supervenes. Lesions involving larger skin area may lead to shock and peripheral circulatory failure.
Diagnosis: It is diagnosed by skin scraping or swab, and skin biopsy examination.
Treatment: Antibiotic containing ointments are used against dermatitis with bacterial involvement. T he antibiotics can be given parenterally to che ck secondary contaminants. The affected area can be painted with astringent lotion like those containing zinc oxide, glycerine and sodium hydroxide. Use of antihistaminic drugs is also beneficial. Non specific protein like milk iodine can be given to the animals for early response. If there is escape of excess fluid, dusting powder containing zinc oxide, tannic acid and starch in the ratio of 2 : 5 : 20 may be used. In severe cases associated with shock, specific treatment for shock is to be adopted.