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Related to histomonosis: Blackhead disease, Histomonas meleagridis


The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.


A protozoa infection by Histomonas meleagridis, which involves the caeca and later the liver, of turkeys (in which it is often fatal), chickens and other galliform birds.

The causative agent, Histomonas meleagridis, is typically transmitted in embryonated eggs of the cecal nematode Heterakis gallinarum , or by direct contact with infected birds.

Clinical findings
Listlessness, drooping wings, unkempt feathers and yellow droppings. Young birds have more acute disease and die within a few days; older birds tend to live longer.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.


A disease chiefly affecting turkeys, caused by Histomonas meleagridis and characterized by ulcerative and necrotic lesions of the liver and cecum, acute onset, and a high mortality rate. It is transmitted inside the eggs of the nematode Heterakis gallinae, which is primarily responsible for maintaining and spreading the infection.
Synonym(s): blackhead (2) .
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
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The effectiveness of benzimidazole derivatives for the treatment and prevention of histomonosis (blackhead) in turkeys.