Causes: Three types of the Duck hepatitis virus. Types 1 and 3 are unrelated picornaviruses. Type 2 is an astrovirus.

Effects: Incubation period is 3-4 days. Symptoms depend on type of virus. In DVH-1 infection, birds fall on their side and kick spasmodically. Death is rapid. In DVH-2, convulsions, opisthotonosis (arching of head and neck) and death. In DVH-3, outstretched legs and opisthotonosis occur.

Ducklings of 1-4 weeks of age may be affected by this acute disease caused by one of three virus types. DVH type 1 is a 20-40 nm, heat stable picornavirus, DVH type 2 is a 28-30 nm astrovirus. DVH type 3 is also a picornavirus, but is unrelated to DVH type 1 virus.

The virus spreads via airborne and fecal-oral routes.

(There is a 3-4 day incubation period)

In DVH-1 birds fall on their sides and kick spasmodically with rapid death. Morbidity can reach 200% and mortality can reach 95%.

In DVH-2 convulsions, opisthotonos (arching of head and neck) and death are evident.

In DVH-3 outstretched legs and opisthotonosis occurs.

DVH-1 produces enlarged liver with punctuated ecchymotic (paint brush) haemorrhages, and enlarged, mottled spleen and the kidney may be swollen and congested.

DVH-2 produces a liver which is pick and has haemorrhages, spleen enlarged, kidneys enlarged and small haemorrhages in the intestinal wall.

DVH-3 lesions are similar to DVH-1.

A rapid onset of clinical signs in ducklings with liver lesions is characteristic. Isolation and identification of organism in duck embryonated eggs and staining of virus with specific fluorescent conjugated antisera is diagnostic.

It simulates Chlamydia psittaci, Salmonellosis, aflatoxicosis and avian influenza.

A live attenuated vaccine is available for use in breeders or ducklings by injection against the DVH-1 type only.

None.

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