In acute cases with a short clinical course, lesions are commonly found in the heart, which has a pale myocardium characteristically rounded at its apex. Swelling and be swollen and congested (10). Serofibrinous perihepatitis and pericarditis
Presence of large volumes of straw-colored fluid in the abdominal cavity.
Pulmonary edema, liver dystrophy, and catarrhal enteritis. Diptheritic and ulcerative lesions in the mouth, pharynx, and esophagus.
Vacuolation and degeneration of hepatocytes.
Degenerative changes in myocardial cells with presence of scattered Cowdry type A intranuclear inclusions.
Isolation and Identification:
Goose parvovirus can be isolated following inoculation of 10- to 15- day-old embryonated goose or Muscovy duck eggs via the allantoic cavity. Embryo mortality occurs 5-10 days postmoculation with hemorrhages on livers.
The virus can also be isolated in primary cell cultures of goose or Muscovy duck embryos cytopathic effect 3-5 days postinfection. In hemotoxylin- and eosin-stained preparations, Cowdry type A intranuclear inclusions and syncytium formation are often present.
Confirmation of goose parvovirus infection can be obtained by serologic identification using specific antiserum: The most commonly used method is the virus neutralization test. Other serologic techniques developed include the ELISA test, agar gel diffusion test and plaque assay.
The disease must be differentiated from Reoviruses and Adenoviruses infections. In such cases, it may be necessary to carry out serologic tests in order to confirm the diagnosis.
PREVENTION AND CONTROL
There is no specific treatment for goose parvovirus infection. Antibiotic therapy has been used only to reduce losses from secondary bacterial or fungal infections.
Because many outbreaks of goose parvovirus are attributed to transmission of the disease during hatching, the practice of incubating and hatching eggs that have originated from different breeding flocks should be discouraged. Only eggs from known parvovirus-free flocks should be used. Good hatchery hygiene should be maintained.
Avoid contact with carriers. All contact geese, whether goslings or adults, should be serologically tested in order to avoid horizontal infection. Positive reactors should be removed from the flock. Provide adequate immunity during the first 4—S wk of life. Serum therapy can be used when the disease subsequently appeared using serum produced in hyper-immunized geese.
Active immunization of adult breeding geese and Muscovy ducks with virulent virus has also been reported. The results showed that good protection against goose parvovirus was transferred to the progeny via the egg yolk. One of the first vaccines against the disease was live attenuated prepared by multiple passage in embryonated goose eggs. Other vaccines have been developed by attenuation of the virus in goose or Muscovy duck embryo cell cultures, for use in breeding geese and go slings. Duck embryo-adapted goose parvovirus vaccines have also been shown to induce a good immune response in goslings and breeder geese. Inactivated vaccines also can be used.