Difference between revisions of "Dermatophilosis"

Revision as of 11:07, 30 June 2010

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

Dermatophilosis in a cow (Courtesy of Bristol BioMed Image Archive)

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

@@ Line 8: / Line 8: @@
 *'''Treatment''':
 **Parenteral antibiotics e.g oxytetracycline, pr penicillin-streptomycin combinations
+[[Image: Dermatophilosis in cow.jpg|100px|thumb|right|<small><center>Dermatophilosis in a cow (Courtesy of Bristol BioMed Image Archive)</center></small>]]
+*Caused by [[Dermatophilus congolensis|''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 [[Parasitic skin infections - Pathology#Parasitic| 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:
+**[[Skin Glossary - Pathology|Papules, pustules, crusts]] may coalesce and mat the coat
+*Microscopically:
+**Hyperplastic superficial perivascular dermatitis
+**Multilaminated crusts, alternating keratin and inflammatory cell layers
 [[Category:Cattle]][[Category:Sheep]][[Category:Horse]][[Category:To_Do_-_Clinical]]