- Caused by Dermatophilus congolensis
- Disease most prevalent in young animals
- Damage to the skin predisposes to infection; blood-sucking insects also thought to be involved in transmission
- Lesions after heavy rainfall predominantly affect dorsum of farm animals
- Papules, serous, exudative matting of hair, raised crusty scabs
- Scab formation more prominent in sheep and cattle than in horses
- Lesions may resolve within weeks if dry weather, or may progress
- Treatment:
- Parenteral antibiotics e.g oxytetracycline, pr penicillin-streptomycin combinations
- Caused by Dermatophilus congolensis
- Affects cattle, horses, sheep mainly
- More common in wet and warm weather
- Transmotted from animal to animal
- Lesions tend to form on dorsal back and extremities
- Associated with skin trauma, prolonged wetting or parasites
- -> penetration of zoospores
- Bacteria proliferate in outer sheath of hair follicles and superficial epidermis
- Gram-positive, filamentous branching organisms, subdivided longitudinally and transversly
- Causing:
- Acute inflammatory response -> neutrophil migration through dermis and epidermis -> formation of microabscesses
- Further penetration of bacteria is thus prevented
- Regenerated epidermis is invaded again by remaining organisms
- Repeated reinfection -> multilaminated pustular crusts
- Grossly:
- Papules, pustules, crusts may coalesce and mat the coat
- Microscopically:
- Hyperplastic superficial perivascular dermatitis
- Multilaminated crusts, alternating keratin and inflammatory cell layers