Goose parvovirus (GPV) is highly infectious among goslings and ducklings. In goslings, infection is fatal, often causing as much as 70%−100% mortality in goslings < 4 weeks old.(1 References Parvovirus of waterfowl is an infectious disease causing oculonasal exudates, watery diarrhea, and high mortality in young goslings and stunted growth and feather abnormalities in older goslings... read more ) Mortality rate decreases as age of infection increases.
Goose parvovirus has been reported from all the major goose-farming countries of Europe and Asia, where the disease is of serious economic significance. GPV infections in Muscovy and related ducks cause similar lesions in young ducklings, while older ducklings develop a shortened beak and dwarfism.
Muscovy ducks, Pekin, and several hybrid duck breeds are also susceptible to a similar parvovirus that has been shown to be genetically related to but different from goose parvovirus. This so-called Muscovy duck parvovirus (MDV) has been isolated from an outbreak among Muscovy ducks in California. In ducklings, MDV causes lesions similar to those of early GPV infection. Goose parvovirus has not been detected in the US.
Ning K, Liang T, Wang M, Dong Y, Qu S, Zhang D. Pathogenicity of variant goose parvovirus, for short beak and dwarfism syndrome of Pekin ducks, in goose embryos and goslings. Avian Pathol. 2018;47(4):391-399. doi:10.1080/03079457.2018.1459040
Etiology of Parvovirus Infection of Waterfowl
First characterized by the Hungarian virologist Domokos Derzsy, parvovirus infection was originally named in his honor. Recently classified as Dependoparvovirus (formerly Dependovirus) anseriform dependoparvovirus 1, the agents of goose parvovirus and Muscovy duck parvovirus are members of the Parvoviridae family. These viruses have no relations to other avian or mammalian parvoviruses. After primary infection, the virus replicates in the intestinal wall and, after a short viremic phase, reaches the heart, liver, and other organs.
Transmission and Epidemiology of Parvovirus Infection of Waterfowl
Outbreaks of parvovirus infection are often initiated in susceptible goslings after vertical transmission of the virus via eggs laid by infected breeder geese. The virus is excreted in large amounts in the feces of infected birds, resulting in rapid lateral spread by direct and indirect means. Evidence suggests that older, subclinically infected geese may act as carriers.
Infected eggs are often the source of the virus when outbreaks of goose parvovirus occur in countries or geographic locations formerly free of the disease. Serologic evidence suggests that the virus is present in several species of wild geese in Europe. No other avian or biologic vectors have been identified. Muscovy duck virus, not known to cause disease in geese, may infect and be excreted from geese and may serve as a source of infection for ducks.
Clinical Findings of Parvovirus Infection of Waterfowl
In susceptible goslings and ducklings, clinical signs of parvovirus infection vary according to the age of the birds. The course of the disease in birds < 1 week old is rapid, with anorexia and death occurring within 2–5 days. Mortality can reach 100% in birds infected in the hatchery.
In 2- to 4-week-old birds, the disease follows a more protracted course, characterized by ocular and nasal discharge, a profuse white diarrhea, and weakness. The eyelids and uropygial glands are red and swollen. Birds that survive the acute stage show profound growth retardation, with loss of feathers and reddening of the skin, particularly on the back. Birds may stand in a penguin-like posture due to accumulation of ascitic fluid in the abdomen. In this age population of goslings and ducklings, mortality can reach 10%; however, morbidity levels may be much higher.
No clinical signs are seen in older birds, although adults will respond immunologically. Goslings infected at a later age may show growth retardation and feather loss on back, neck, and wings.
Gross lesions include the presence of a fibrinous pseudomembrane covering the tongue, oral cavity, and small intestine as well as perihepatitis, pericarditis, pulmonary edema, liver dystrophy, and catarrhal enteritis. In acute cases, the heart is characteristically rounded at the apex, with a pale myocardium. The main microscopic lesions are pronounced degenerative changes in the myocardial cells and the presence of Cowdry type A intranuclear inclusion bodies.
Similar heart and liver lesions are found with MDV in ducklings. Stunting of growth can be found in infected goslings and ducks. Goslings will have feather loss while ducks will have a dystrophic beak, often with protrusion of the tongue.
Diagnosis of Parvovirus Infection of Waterfowl
Increased mortality in goslings < 3 weeks old with appropriate gross lesions
Stunted goslings and ducklings, especially ducklings with dystrophic beaks
A presumptive diagnosis of parvovirus infection is based on the characteristic clinical course, age incidence, and gross and histologic lesions. Confirmation can be obtained after isolation of the parvovirus in primary cell cultures or embryonated eggs derived from susceptible geese and Muscovy ducks. Presence of the virus can be confirmed by electron microscopic examination of infected cultures and neutralization with specific goose parvovirus antiserum.
Diagnosis can also be confirmed by direct detection of antigen or virus in tissues from infected birds, by immunofluorescence, or by the use of PCR assay. Serologic tests for goose parvovirus include virus neutralization, agar gel precipitation, immunofluorescence, and ELISA.
Although goose parvovirus causes disease in both geese and Muscovy ducks, Muscovy ducks are also infected with MDV, which is antigenically related. This virus causes serious disease in Muscovy ducklings, but not in goslings, and can be detected and differentiated using PCR assay combined with sequencing or restriction fragment length polymorphism.
Differential diagnoses should also include duck viral enteritis Duck Viral Enteritis (duck plague), which affects all types of waterfowl. Duck viral hepatitis Duck Viral Hepatitis causes a fatal disease in ducklings but is not pathogenic for goslings or Muscovy ducklings. Riemerella anatipestifer Riemerella anatipestifer Infection and Pasteurella multocida may also cause high mortality in goslings and Muscovy ducklings; however, they can be differentiated by bacterial isolation and identification.
Prevention and Treatment of Parvovirus Infection of Waterfowl
Appropriate vaccination of breeders
No treatment available
To prevent parvovirus infection, goslings should be hatched together only from flocks that are known to be free of goose parvovirus; many outbreaks are attributed to the practice of custom-hatching eggs from various sources. Eggs should be imported only from countries that can guarantee freedom from goose parvovirus. Geese that have survived an outbreak should not be used for breeding purposes.
Both live, inactivated oil emulsion vaccines and baculovirus-expressed VP2 capsid-based recombinant vaccines are available and are widely administered in countries where the disease is endemic. Vaccination of breeding flocks induces high levels of maternal antibody in the progeny until ~2 weeks of age.
Waterfowl parvovirus infection should be considered during high mortality events in very young goslings and Muscovy ducklings.
Stunting and poor feathering in gosling and duck flocks may also be a sequela of parvoviral infection.
Shortened beaks combined with stunting of goslings and ducks may also be an indication of an earlier parvoviral infection.
For More Information
Derzsy D. A viral disease of goslings. I. Epidemiological, clinical, pathological and aetiological studies. Acta Vet Acad Sci Hung. 1967;17(4):443-448.
Cotmore SF, Agbandje-McKenna M, Chiorini JA, et al. The family Parvoviridae. Arch Virol. 2014;159(5):1239-1247. doi:10.1007/s00705-013-1914-1
Yen T-Y, Li K-P, Ou S-C,Shien J-H, Chang P-C. The white roman goose as a host for infection and viral shedding of Muscovy duck parvovirus. Taiwan Vet J. 2015;41(2):85-89. doi:10.1142/S1682648515500079
Glávits R, Zolnai A, Szabó E, et al. Comparative pathological studies on domestic geese (Anser anser domestica) and Muscovy ducks (Cairina moschata) experimentally infected with parvovirus strains of goose and Muscovy duck origin. Acta Vet Hung. 2005;53(1):73-89. doi:10.1556/AVet.53.2005.1.8