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 1: / Line 1: @@
-{{OpenPagesTop}}
+*Caused by [[Dermatophilus congolensis]]
-Also known as: '''''Cutaneous streptothrichosis'''
+**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
-==Introduction==
-This is a group of diseases affecting the epidermis caused by  [[Dermatophilus congolensis|''Dermatophilus congolensis'']]. It causes a range of conditions in large animals including rain scald in horses and strawberry foot rot in sheep. The disease is associated with skin trauma, prolonged wetting or [[:Category:Integumentary System - Parasitic Infections| parasites]]. Lesions typically involve exudative dermatitis with scab formation. It is a zoonosis affecting humans in close contact with infected animals.
-==Signalment==
+[[Image: Dermatophilosis in cow.jpg|100px|thumb|right|<small><center>Dermatophilosis in a cow (Courtesy of Bristol BioMed Image Archive)</center></small>]]
-Can be seen in animals of all ages but most commonly occurs in young animals who are chronically exposed to moisture.
-Affects horses, sheep, cattle, goats, pigs and rarely dogs and cats.
-==History and Clinical signs==
+*Caused by [[Dermatophilus congolensis|''Dermatophilus congolensis'']]
-Lesions commonly occur following heavy rainfall and commonly affects the dorsum of animals. Any previous trauma or damage to the skin can predispose to infection. Blood-sucking insects are also thought to be involved in transmission.
+*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
-<big>'''[[Dermatophilosis - Horse|Equine dermatophilosis]]
+[[Category:Cattle]][[Category:Sheep]][[Category:Horse]][[Category:To_Do_-_Clinical]]
-'''[[Dermatophilosis - Sheep|Ovine dermatophilosis]]
-'''[[Dermatophilosis - Cattle|Bovine dermatophilosis]]
-</big>
-==Diagnosis==
-Diagnosis can often be made on history and physical exam. '''Impression smears''' can also be useful when stained with either gram stain or Giemsa and examined microscopically.
-Additionally it is possible to '''culture material from the crusts''' however this can be difficult due to the slow growing nature of the pathogen.
-==Pathology==
-Grossly:
-Papules, pustules, crusts may coalesce and mat the coat.
-Microscopically:
-*Hyperplastic superficial perivascular dermatitis
-*Multilaminated crusts, alternating keratin and inflammatory cell layers
-==Prognosis==
-Good if animals are kept dry. Often re-occurs in wet weather.
-{{Learning
-|literature search = [http://www.cabdirect.org/search.html?rowId=2&options2=OR&q2=dermatophilosis&occuring2=title&rowId=3&options3=AND&q3=&occuring3=freetext&publishedstart=2000&publishedend=yyyy&calendarInput=yyyy-mm-dd&la=any&it=any&show=all&x=39&y=14 Dermatophilosis publications since 2000]
-}}
-==References==
-Merck & Co (2008) '''The Merck Veterinary Manual''' (Eighth Edition) ''Merial''
-th year Veterinary Dermatology notes. Royal Veterinary college. October-November 2008. p60-64.
-{{review}}
-{{OpenPages}}
-[[Category:Dermatological Diseases - Pig]][[Category:Dermatological Diseases - Goat]][[Category:Zoonoses]][[Category:Dermatological Diseases - Dog]][[Category:Dermatological Diseases - Cat]]
-[[Category:Expert Review]]
-[[Category:Integumentary System - Bacterial Infections]]

Difference between revisions of "Dermatophilosis"

Revision as of 11:07, 30 June 2010

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