{{short description|Bacterial skin disease of cattle and horses}} '''Rain scald''' (also known as dermatophilosis, tufailosis, rain rot, or streptothricosis<ref name="Macadam">{{cite journal|last=Macadam|first=I.|date=September 1, 1970|title=Some observations on bovine cutaneous streptothricosis in Northern Nigeria ds/tahm/2.04.10_DERMATOPHIL.pdf|journal=OIE}}</ref>) is a dermatological disease affecting cattle and horses. Once in the skin, the bacterium ''Dermatophilus congolensis'' causes inflammation of the skin as well as the appearance of scabs and lesions.
==Symptoms and signs== There are two different manifestations of rain scald: the winter form, which is more severe due to the longer coat of the horse, and the summer form, which is less severe.<ref name="Szczepanik">{{cite journal|last=Szczepanik|first=Marcin|author2=Marcin Golynski |author3=Dorota Pomorska |author4=Piotr Wilkolek |author5=Iwona Taszkun |author6=Marcel Kovalik |title=Dermatophilosis in a horse - a case report|journal=Bulletin of the Veterinary Institute in Pulawy|year=2006|volume=50|pages=619–622|url=http://bulletin.piwet.pulawy.pl/images/stories/pdf/20064/20064619622.pdf|access-date=10 November 2011}}</ref> Horses are usually affected on the back, head, and neck where insects commonly bite, and the legs, which are commonly infected if the horse is kept in moist footing.<ref name="Iowa State">{{cite web|title=Fast Facts: Dermatophilosis|date=January 2006|url=https://www.cfsph.iastate.edu/FastFacts/pdfs/dermatophilosis_F.pdf|publisher=The Center for Food Security & Public Health Iowa State University|access-date=10 November 2011}}</ref> Initially, the horse will display a matted coat and bumps which will progress to crusty scabs and lesions.<ref name="Merck">{{cite web|title=Dermatophilosis: Introduction|url=http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/70600.htm|work=The Merck Veterinary Manual|publisher=Merck SHarp & Dohme Corp.|access-date=10 November 2011}}</ref> The animal may also be pruritic and display signs of discomfort.{{cn|date=June 2021}}
==Diagnosis== Diagnosis is most commonly done with the identification of bacteria in the lesions by microscopic evaluation.<ref name="OIE">{{cite web|title=Dermatophilosis|date=2008|url=http://www.oie.int/fileadmin/Home/eng/Health_standards/tahm/2.04.10_DERMATOPHIL.pdf|publisher=OIE|access-date=7 November 2011}}</ref> A positive diagnosis of rain scald can be confirmed if filamentous bacteria are observed, as well as chains of small, spherical bacteria (cocci).<ref name="Merck" /> If a diagnosis cannot be confirmed with a microscope, blood agar cultures can be grown to confirm the presence of ''D. congolensis''.<ref name="OIE" /> The resulting colonies have filaments and are yellow in colour.{{cn|date=June 2021}} ==Prevention== In addition to wet conditions, exposure to ticks, biting flies, and contact with other infected animals can also cause the spread of rain scald.<ref name="Iowa State" /> Tick and insect control is an effective way to stop the spread of the bacteria from one animal to another.<ref name="OIE" /> Separating infected animals will help to isolate bacterial colonies.<ref name="Iowa State" /> Keeping the animal in a dry, well-ventilated area out of the rain and wet conditions will stop the bacteria from growing.<ref name="Merck" />
==Treatment== Rain scald normally heals on its own; however, the condition can spread, so prompt treatment is recommended. Although some cases can be severe, most rain scald is minor and can be treated at home naturally.{{cn|date=June 2021}}
Typically the condition is not life-threatening, nor does it impact the welfare of the horse, so treatments are more for the owner's peace of mind and cosmetic appeal of the animal.<ref name="Merck" />
==References== {{reflist}}
Category:Horse diseases Category:Bacterium-related cutaneous conditions Category:Bovine diseases