Encyclopedia of Parasitology

Living Edition
| Editors: Heinz Mehlhorn

Blue Tongue Disease (BTD)

  • Heinz Mehlhorn
Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-27769-6_421-2



French: fièvre catarrhale du mouton; Spanish: lengua atul; African: bloutang.

This disease occurs in wild and stock ruminants due to infections with BTD virus that is transmitted in Africa mainly by Culicoides imicola, in Central Europe (new) by C. obsoletus, in the USA by C. variipennis, and in Australia by the C. schultzei group.

Symptoms of Disease

Characteristics are the name-giving blue tongue due to cyanosis (rather rare); severe nasal discharge; subcutaneous hyperemia; petechae; lacrymation; facial, mouth, udder, and lung edema; swollen lymph nodes; and typical foot lesions leading to general stiffness, abortion, torticollis, and death.

Mortality Rate

In sheep, death rate reaches 80 %, 3–5 % in cattle, and very low rates (if at all) occur in wild ruminants.


Lymph Node Death Rate Nasal Discharge Lung Edema Wild Ruminant 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  1. 1.Institut für Zoomorphologie, Zellbiologie und ParasitologieHeinrich-Heine-UniversitätDüsseldorfGermany