Duck virus hepatitis (DVH)
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.
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.
Signs include sudden, high persistent mortality, and a drop in egg production (25-40%). Photophobia can occur as half-closed, pasted eyelids. Inappetance, extreme thirst, droopiness, ataxia, ruffled feathers, nasal discharge, soiled vents, and watery diarrhoea may also be evident. Birds may be unable to stand, and have droopy outstretched wings, and head down. Tremors of the head, neck and body, loss of weight, blue beaks, blood stained vent, and mortality (5-100%) may be seen.
Lesions include vascular damage (tissue haemorrhages) and free blood in the body cavity. Eruptions in the GI tract, and degeneration of lymphoid organs (thymus and bursa) may be seen. Petechial haemorrhage may be seen on the myocardium, on liver, pancreas, intestine, lungs and kidney. Surface haemorrhages and yellow-white crusty plaques on the mucosa of the oral cavity, oesophagus, ceca and cloaca may be evident.
Clinical signs and gross lesions in all age ducks are diagnostic. It simulates influenza, duck viral hepatitis, and fowl cholera.
Treatment & control
An inactivated vaccine for breeders and a live attenuated vaccine by injection for ducklings can be used.