Integumentary system: Skin, hoof, and claw

The skin acts as a barrier to provide protection of the interior environment from exterior environment. There are two primary layers of the skin, the epidermis and dermis. Skin diseases either only involve skin or can be cutaneous manifestations of internal disease. Skin biopsy is appropriate for most lesions, including suspected neoplasm, persistent ulceration, and lesions not responding to treatment. Exudative epidermitis occurs with those strains of Staphylococcus hyicus that produce a heat-labile exfoliative toxin. Pustular dermatitis is a result of streptococcal infections that cause skin necrosis and pustular dermatitis. Ulcerative dermatitis can occur as ulcerative, necrotic, or tumor-like lesions found on the body surface. Swinepox is a typical poxvirus infection mainly affecting young pigs. Fungal diseases of swine tend to be superficial mycoses involving the keratinized epithelial cells and hair only. Photosensitization is a condition seen in extensive, freerange- managed swine exposed to photodynamic agents and sunlight.