Chicken and turkey parvovirus infections occur worldwide and primarily affect growing birds. The main clinical signs associated with infection are related to production and include poor weight gain, increased feed conversion ratio, and failure to thrive. Diarrhea and increased mortality rate can also occur. Diagnosis is mainly by PCR assay. There are no commercial vaccines, so prevention relies on good biosecurity and husbandry.
Chicken parvoviruses (ChPVs) and turkey parvoviruses (TuPVs) are members of the genus Aveparvovirus and are distinct from the dependoparvoviruses affecting waterfowl. Chicken and turkey parvoviruses were reported in the early 1980s and have been shown to have a worldwide range.
Aveparvoviruses have been linked to a number of enteric production disease syndromes affecting growth rate, such as malabsorption syndrome, poult enteritis complex, and the more damaging poult enteritis mortality syndrome. Recent studies have confirmed the role of ChPVs in malabsorption syndrome (1). Chicken and turkey parvoviruses require actively dividing host cells (eg, intestinal or lymphoid tissues) to replicate.
Etiology and Transmission of Chicken Parvovirus and Turkey Parvovirus Infections
Although vertical transmission of chicken and turkey parvoviruses from hen to egg has been observed, the major route of transmission appears to be horizontal, through the fecal-oral route and exposure to environmental contamination. ChPV and TuPV are usually confined to their homologous host (chicken or turkey, respectively); however, cross-species transmission has been posited based on genetic characterization of some chicken and turkey parvoviruses.
In broiler chickens, molecular detection of ChPV tends to occur within the first week after hatching and to peak in the second or third week. These infections can persist at high levels throughout the lifetime of the flock.
Aveparvoviruses are very stable (ie, resistant to heat, extremes of pH, and disinfection) in the poultry house environment.
Clinical Findings of Chicken Parvovirus and Turkey Parvovirus Infections
With chicken and turkey parvovirus-associated production diseases, such as malabsorption syndrome, poult enteritis complex, and poult enteritis mortality syndrome, the main clinical findings are poor or uneven weight gain, poor feed conversion, and failure to thrive. Diarrhea, feather abnormalities, and increased mortality rates have also been reported in more severe cases.
Lesions
Acute catarrhal small intestinal enteritis has been observed in histological examination, as has moderate to severe distension of intestinal crypts with associated eosinophilic intranuclear inclusions within epithelial cells. Parvovirus DNA has been detected by PCR assay in broilers with clinical signs of enteric diseases, curvature of the duodenal loop, pancreatic atrophy, and mesenteric inflammation. Gross lesions include atrophy of the pancreas, cloacal bursa, and spleen.
ChPVs have been associated with the development of lymphocytic pancreatitis, heterophilic pancreatitis, and pancreatic atrophy. Immunohistochemical testing has detected parvovirus in the cloacal bursal follicles of turkeys.
Diagnosis of Chicken Parvovirus and Turkey Parvovirus Infections
PCR assay
Diagnosis of one of the production disease syndromes associated with parvovirus infections is commonly made based on poor flock performance metrics along with the presence of other clinical findings, as described above. A number of molecular methods (eg, PCR and quantitative real-time PCR assays) have been used to detect ChPV and TuPV viral nucleic acid. Aveparvoviruses have been detected using both immunohistochemical analysis on tissue sections and ELISA on sera.
Treatment and Prevention of Chicken Parvovirus and Turkey Parvovirus Infections
Biosecurity
Animal husbandry
No commercial chicken or turkey parvovirus vaccine is available, and these viruses are not easily grown in culture, precluding the use of endogenous vaccines. Exposure to these viruses can be minimized through robust biosecurity, good husbandry, and effective sanitation measures in both parent and broiler flocks. These measures include disinfection of machinery and housing, all-in all-out production systems, and adequate downtime between flocks.
Zoonotic Risk of Chicken Parvovirus and Turkey Parvovirus Infections
No zoonotic risk of transmission of either chicken parvovirus or turkey parvovirus infections has been reported.
Key Points
Chicken and turkey parvoviruses are widespread and typically affect growing birds.
No treatments or commercial vaccines are available, so prevention is by good biosecurity and husbandry.
For More Information
Day JM. Enteric parvovirus infections of chickens and turkeys. In: Swayne DE, ed. Boulianne M, Logue CM, McDougald LR, Nair V, Suarez DL, associate eds. Diseases of Poultry. 14th ed. Wiley; 2020: 426-431.
Pfleiderer L, Vaillancourt JP. Other viral enteric infections. In: Brugere-Picoux J, Vaillancourt JP, Shivaprasad HL, Venne D, Bouzouaia M, eds. Manual of Poultry Diseases. French Association for the Advancement of Science; 2015:194-199.
Zsak L, Cha RM, Day JM. Chicken parvovirus-induced runting-stunting syndrome in young broilers. Avian Dis. 2012;57(10):123-127.
References
Finkler F, Lima DA, Cerva C, et al Chicken parvovirus and its associations with malabsorption syndrome. Res Vet Sci. 2016;107:178-181. doi:10.1016/j.rvsc.2016.06.001
