Occurrence: North America, Europe, Asia.
Species affected: Ducks, geese, swans.
Age affected: All.
Causes: Herpes virus.
Effects: Sudden, high and persistent mortality. Drop in egg production (25-40%). Photophobia- half-closed, pasted eyelids. Inappetance, extreme thirst, droopiness, ataxia, ruffled feathers, nasal discharge, soiled and/or bloodstained vents, watery diarrhoea. Tremors of the head, neck and body, weight loss, blue beaks and mortality (5-100%) may also be seen.
Special note: It is immunosuppressive.
Duck virus hepatitis (DVH)
Ducks geese and swans of all ages are susceptible to the duck enteritis virus, which is a herpes virus transmitted from bird to bird, by bloodsucking arthropods, or by contact with contaminated environment or water.