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==Overview==
*Important emerging disease of amphibians caused by the fungus ''Batrachochytrium dendrobatidis'' (Bd). Pathogenic, virulent and highly transmissible.
*Important emerging disease of amphibians caused by the fungus ''Batrachochytrium dendrobatidis'' (Bd). Pathogenic, virulent and highly transmissible.
*Infection has been recognised in a wide range of bot anuran (frogs and toads) and urodele (salamanders and newts) amphibians.
*Infection has been recognised in a wide range of bot anuran (frogs and toads) and urodele (salamanders and newts) amphibians.
*Is an international notifiable disease (World Organisation for Animal Health, 2008).
*Is an international notifiable disease (World Organisation for Animal Health, 2008).
==Characteristics==
*"Chytrids" are true fungi that produce characteristic, motile, posteriorly uniflagellate zoospores within discrete fungal bodies called ''thalli''.
*"Chytrids" are true fungi that produce characteristic, motile, posteriorly uniflagellate zoospores within discrete fungal bodies called ''thalli''.
*Ubiquitous in aquatic enrivonments.
*Ubiquitous in aquatic enrivonments.
==Pathogenesis==
*Lesions limited to keratinizing epithelium in the skin of postmetamorphic animals and the mouthparts (tooth rows and jaw sheaths) of tadpoles.
*Lesions limited to keratinizing epithelium in the skin of postmetamorphic animals and the mouthparts (tooth rows and jaw sheaths) of tadpoles.
*Varying degrees of epidermal hyperplasia and hyperkeratosis, with intralesional thalli characterisitic of Bd.
*Varying degrees of epidermal hyperplasia and hyperkeratosis, with intralesional thalli characterisitic of Bd.
*Transmission of Bd infection is via zoospores during direct contact between animals or contact with water or substrates.
*Transmission of Bd infection is via zoospores during direct contact between animals or contact with water or substrates.
==Clinical signs==
*Variable, ranging from unexpected death without previous signs, to evidence of skin disease.
*Variable, ranging from unexpected death without previous signs, to evidence of skin disease.
*Skin (typically microscopic and not detectable): excessive sloughing; granular changes in skin texture; hyperemia skin discolouration. These are frequently observed on the ventral body and feet of terrestrail species, but may be diffuse in completely aquatic animals.
*Skin (typically microscopic and not detectable): excessive sloughing; granular changes in skin texture; hyperemia skin discolouration. These are frequently observed on the ventral body and feet of terrestrail species, but may be diffuse in completely aquatic animals.
*Neurologic: Loss of righting reflex; tetanic spasms; paralysis.
*Neurologic: Loss of righting reflex; tetanic spasms; paralysis.
==Diagnosis==
*Light Microscopy
*Light Microscopy
**Examination of skin slough with or without staining.
**Examination of skin slough with or without staining.
*Real-time Taqman PCR which quantifies DNA in the sample.
*Real-time Taqman PCR which quantifies DNA in the sample.
==Prevention and Control==
*In captive populations, enclosures should be disinfected and husbandry protocols implemented to prevent cross-contamination of water or substrate. Quarantine of newly aquired animals is essential.
*In captive populations, enclosures should be disinfected and husbandry protocols implemented to prevent cross-contamination of water or substrate. Quarantine of newly aquired animals is essential.
*Temperature: Cultures of Bd die above 32°C (optimum growth is 17°-25°C) and so this has potential for use as a primary or adjunctive treatment in species that tolerate higher environmental temperatures.
*Temperature: Cultures of Bd die above 32°C (optimum growth is 17°-25°C) and so this has potential for use as a primary or adjunctive treatment in species that tolerate higher environmental temperatures.
*Adult animals may be bathed in 0.01% itraconazole suspension for 5 minutes daily, up to 11 days.
*Adult animals may be bathed in 0.01% itraconazole suspension for 5 minutes daily, up to 11 days.
*Surveillance should be performed by complete necropsies, including histopathology, on all dead animals. Screening for Bd by PCR of skin scrapings or skin swabs may be implemented, in addition to prophylactic antifungal treatment of entire groups originating from high-risk areas.
*Surveillance should be performed by complete necropsies, including histopathology, on all dead animals. Screening for Bd by PCR of skin scrapings or skin swabs may be implemented, in addition to prophylactic antifungal treatment of entire groups originating from high-risk areas.