Duck Viral Enteritis (Duck Plague): Etiology, Diagnosis, and Control

Introduction

Duck viral enteritis (DVE), also known as duck plague, is an acute, contagious, and often fatal disease of Anseriformes, including ducks, geese, and swans, caused by anatid herpesvirus 1 (AHV-1) [1]. The disease is characterized by vascular damage, hemorrhagic lesions, and high mortality in naive populations [2, 3]. Despite the availability of live attenuated vaccines, outbreaks continue to occur in vaccinated flocks, indicating antigenic drift or incomplete vaccine coverage [1]. This article provides an exhaustive review of DVE etiology, epidemiology, clinical signs, pathology, diagnostics, treatment, and control, with an emphasis on molecular diagnostic tools and modern vaccine development.

What Is Ducks Disease?

The colloquial phrase "ducks disease" has historically been applied to several enteric syndromes in waterfowl, but in veterinary medicine it most specifically refers to duck viral enteritis (duck plague) [1, 2]. This term distinguishes AHV-1 infection from other waterfowl pathogens such as duck hepatitis A virus, duck circovirus, or duck astrovirus [4, 5, 35]. Ducks disease, in the context of this article, denotes the acute herpesviral infection causing systemic hemorrhagic disease and high mortality in Anseriformes.

Etiology

Duck viral enteritis is caused by anatid herpesvirus 1 (AHV-1), a member of the subfamily Alphaherpesvirinae within the family Herpesviridae [2, 6]. The virion is enveloped with an icosahedral capsid approximately 150 nm in diameter and contains a linear double-stranded DNA genome of about 160 kb [2, 3]. The genome encodes numerous proteins involved in replication, immune evasion, and virulence [7, 8]. For instance, the UL50 gene product is essential for viral replication and pathogenesis in vivo [7]. The UL24 protein antagonizes the host innate immune response by initiating K48/K63-linked polyubiquitination of interferon regulatory factor 7 (IRF7) [8]. The LORF4 gene, in contrast, is a late gene nonessential for in vitro replication [9]. The host actin-myosin II network regulates viral proliferation, as demonstrated by proteomic targeting of the VP26 protein [10].

Strains of AHV-1 vary in virulence. A virulent strain isolated from northern Bangladesh showed high pathogenicity in experimental infections [2]. A Chinese variant with a deletion in the UL2 gene exhibited altered biological characteristics and reduced pathogenicity [3, 11]. Complete genome sequencing of the XJ strain enabled construction of an infectious bacterial artificial chromosome clone, facilitating functional genomic studies [6]. Virulence attenuation can be achieved through combined gene deletion, as demonstrated in a vaccine strain that restored gut microbiota balance and enhanced safety [12].

Epidemiology

DVE occurs worldwide in domestic and wild waterfowl populations [1, 33]. Transmission occurs horizontally via direct contact with infected birds or contaminated water and fomites [1]. The virus is shed in feces, oral secretions, and through the cloaca [2]. Wild migratory birds play a role in viral dispersal, as demonstrated by detection of viral pathogens in U.S. game-farm mallards, indicating spillover risk [33]. Coinfections with other waterfowl viruses, such as duck circovirus, duck astrovirus, goose parvovirus, and duck hepatitis A virus, are common and can exacerbate disease severity [13, 4, 5, 14, 35]. Epidemiologic surveys in Thailand have revealed genetic diversity among duck circovirus strains, which may modulate immune responses to DVE [5]. Differential susceptibility among waterfowl species has been observed; ducks are more vulnerable to certain deltacoronaviruses than geese, though DVE remains highly pathogenic across Anseriformes [15].

Clinical Signs

The incubation period ranges from 3 to 7 days in natural infections [1]. Clinical signs include sudden death, depression, anorexia, photophobia, ataxia, and prostration [1, 16]. Ocular and nasal discharges are common. Diarrhea is frequent, with feces ranging from watery to bloody [1]. In laying flocks, egg production drops sharply [1]. Hemorrhagic lesions on the mucous membranes of the upper digestive tract and vent are characteristic [1, 16]. Morbidity and mortality can reach 90% in naive populations [1, 33]. In vaccinated flocks, clinical signs may be milder and mortality lower [1].

Pathology

Gross pathological findings include extensive hemorrhages on the serosal surfaces of the heart, liver, pancreas, and intestinal tract [1]. The esophagus, pharynx, and cloaca exhibit diphtheritic lesions and erosions [1, 16]. The liver is enlarged and friable with petechial hemorrhages. The spleen is mottled and often enlarged [1]. Histopathology reveals intranuclear inclusion bodies in hepatocytes and epithelial cells of the digestive tract [16]. Vascular endothelial damage leads to thrombosis and necrosis [1, 16]. Intestinal pathology can be alleviated by poly(I:C) treatment through inhibition of apoptosis, indicating the role of innate immune signaling in disease progression [31].

Diagnostics

Rapid and specific diagnosis is critical for outbreak control. A variety of molecular assays have been developed for detection of AHV-1. Real-time fluorescence recombinase polymerase amplification (RPA) enables rapid detection of virulent strains with high sensitivity and specificity [17]. Multienzyme isothermal rapid amplification (MIRA) assays, including MIRA-qPCR and MIRA lateral flow dipstick (LFD), provide field-deployable point-of-care diagnostics [18]. A visual gene chip method allows simultaneous detection of seven waterfowl viral pathogens, including AHV-1, duck tembusu virus, novel duck reovirus, and duck hepatitis A virus types 1 and 3 [19]. TaqMan-probe-based multiplex real-time RT-qPCR panels can differentiate multiple waterfowl viruses in a single reaction [4]. Serological detection of antibodies against duck circovirus using recombinant capsid protein-based indirect ELISA is available, though direct detection of AHV-1 antigen by ELISA is less common [13]. Virus isolation in chicken embryo fibroblasts or duck embryo fibroblasts remains a gold standard for confirmation [1, 34].

The diagnostic workflow for suspected DVE is presented in Figure 1.

graph TD
    A[Suspected DVE case], > B[Clinical signs & necropsy]
    B, > C{Collect samples}
    C, > D[Liver, spleen, intestinal tissue]
    C, > E[Oropharyngeal/cloacal swabs]
    D, > F[Virus isolation on cell culture]
    E, > G[DNA extraction]
    F, > H[Observation of CPE & confirmation]
    G, > I[Real-time RPA / MIRA]
    G, > J[Multiplex RT-qPCR]
    G, > K[Visual gene chip]
    H & I & J & K, > L[Positive for AHV-1?]
    L, > M[Yes: Confirm DVE outbreak]
    L, > N[No: Consider differentials]
    N, > O[Test for: DHAV, DRV, DTMUV, circovirus, astrovirus]
    O, > P[Report & implement control measures]

Figure 1. Diagnostic algorithm for duck viral enteritis.

A summary of diagnostic methods is provided in Table 1.

Table 1. Diagnostic methods for duck viral enteritis.

Treatment

No specific antiviral therapy is approved for DVE. Supportive care includes maintaining hydration and reducing stress [1]. Immunomodulatory agents such as poly(I:C) have shown experimental efficacy in reducing intestinal pathology [31]. Piperazine, a small molecule, inhibited AHV-1 infection in vitro by modulating host cytokines, suggesting potential for therapeutic development [20]. Antibiotic therapy may be indicated to control secondary bacterial infections, especially in field settings [1]. Prompt removal of dead birds and decontamination of the environment are critical to limit spread [1].

Control

Vaccination

Vaccination is the cornerstone of DVE control. Live attenuated vaccines are widely used in domestic duck flocks [1, 34]. An Indian strain-based vaccine produced in chicken embryo fibroblasts has been developed and evaluated for safety and efficacy [34]. Recombinant vector vaccines using duck enteritis virus as a backbone have been engineered to express immunogenic genes from other pathogens, such as duck hepatitis A virus type 3 and goose astrovirus capsid protein, providing dual protection [21, 22]. A CRISPR/Cas9-edited DEV expressing Pmp17G of Chlamydia psittaci induced protective immunity in ducklings [23]. Recombinant DEV harboring influenza virus hemagglutinin genes rapidly induced specific cellular immunity in ducks [24]. The current status of DEV-vectored vaccines has been comprehensively reviewed [25]. Tissue tropism and horizontal transmission of a DEV-vectored vaccine in one-day-old chickens were evaluated, indicating safety in off-target species [26]. Gene deletion in the vaccine strain, such as combined deletions targeting intestinal pathogenicity factors, improves safety and restores gut microbiota balance [12].

Biosecurity

Strict biosecurity measures prevent introduction and spread of AHV-1. These include isolation of new birds, sanitation of equipment and footwear, and control of wild bird access [1, 33]. In game-farm operations, monitoring for viral pathogens flags spillover risk to wild populations [33].

Eradication and Quarantine

In outbreak situations, depopulation of infected flocks followed by thorough disinfection and a fallow period is recommended [1]. Quarantine zones and movement restrictions help contain the virus [1, 33].

Cross-Linking to Related Articles

For further reading on related waterfowl pathogens, see the articles on Duck Viral Enteritis (Duck Plague): Etiology, Clinical Signs, and Control, Duck Hepatitis A Virus, Duck Circovirus, Duck Tembusu Virus, and Duck Astrovirus. Differential diagnoses from bacterial conditions such as Fowl Cholera in Poultry and Riemerella anatipestifer Infection in Ducks are also important.

Disclaimer: This article is for educational and informational purposes only. It is not intended to substitute for professional veterinary advice, diagnosis, treatment, or regulatory guidance. Always consult a licensed veterinarian or qualified specialist regarding animal health, disease diagnosis, and therapeutic decisions.

References

[1] Sang S, Wang H, Dan Y, et al. Isolation, identification and pathogenicity analysis of a virulent duck enteritis virus strain causing outbreak in vaccinated duck flocks. Poult Sci. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42322961/

[2] Yasmin L, Siddique MS, Islam T, et al. Complete genome sequence of a virulent duck enteritis virus isolated from Northern part of Bangladesh. Microbiol Resour Announc. 2025. URL: https://pubmed.ncbi.nlm.nih.gov/41134219/

[3] Yang H, Zhang B, Yang X, et al. Complete genome sequence and biological characteristics of a novel duck enteritis virus variant with a deletion in UL2. Arch Virol. 2025. URL: https://pubmed.ncbi.nlm.nih.gov/40991013/

[4] Qiu Q, Hu R, Liu Z, et al. Taqman-probe-based multiplex real-time RT-QPCR for simultaneous detection of duck tembusu virus, novel duck reovirus, duck hepatitis a type 1 virus and duck hepatitis a type 3 virus. Poult Sci. 2025. URL: https://pubmed.ncbi.nlm.nih.gov/40644908/

[5] Kulprasertsri S, Songserm T, Phatthanakunanan S, et al. Molecular genotyping and subgenotyping of duck circovirus at duck farms in Thailand. Vet World. 2024. URL: https://pubmed.ncbi.nlm.nih.gov/39507780/

[6] Huo SX, Zhu YC, Chen L, et al. Complete Genome Sequence and Construction of an Infectious Bacterial Artificial Chromosome Clone of a Virulent Duck Enteritis Virus Strain XJ. Transbound Emerg Dis. 2024. URL: https://pubmed.ncbi.nlm.nih.gov/40303036/

[7] Huo SX, Chen L, Bao ED, et al. Functional characterization of UL50 gene reveals its essential role in duck enteritis virus replication and pathogenesis. Vet Q. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/41876382/

[8] Ruan P, Chen Y, Wang M, et al. Duck plague virus UL24 protein initiates K48/K63-linked IRF7 polyubiquitination to antagonize the innate immune response. Poult Sci. 2024. URL: https://pubmed.ncbi.nlm.nih.gov/39418790/

[9] Huang J, Wang M, Cheng A, et al. Duck

[10] Chen L, Zhu YC, Yun T, et al. Proteomic Screening for Cellular Targets of the Duck Enteritis Virus Protein VP26 Reveals That the Host Actin-Myosin II Network Regulates the Proliferation of the Virus. Int J Mol Sci. 2025. URL: https://pubmed.ncbi.nlm.nih.gov/41009665/

[11] Yin D, Gao Y, Xu M, et al. Pathogenic mechanisms and molecular features of a novel UL2 gene-deficient duck enteritis virus endemic to China. Virulence. 2025. URL: https://pubmed.ncbi.nlm.nih.gov/40801158/

[12] Kong J, Han C, Shao G, et al. Virulence attenuation of intestinal pathogenicity via combined gene deletion in duck enteritis vaccine strain restores gut microbiota balance and enhances safety. Poult Sci. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/41764962/

[13] Luengyosluechakul T, Kulprasertsri S, Jala S, et al. Development and validation of a recombinant capsid protein-based indirect enzyme-linked immunosorbent assay for serological detection of duck circovirus in commercial flocks. Vet World. 2025. URL: https://pubmed.ncbi.nlm.nih.gov/41472761/

[14] Lebdah MA, Eid AAM, ElBakrey RM, et al. Novel goose parvovirus in naturally infected ducks suffering from locomotor disorders: molecular detection, histopathological examination, immunohistochemical signals, and full genome sequencing. Avian Pathol. 2025. URL: https://pubmed.ncbi.nlm.nih.gov/39418082/

[15] Liu R, Meng S, Shuai L, et al. Differential Susceptibility to Porcine Deltacoronavirus: Ducks Show Greater Vulnerability Than Geese. Transbound Emerg Dis. 2025. URL: https://pubmed.ncbi.nlm.nih.gov/40503219/

[16] Shi X, Zhuang H, Shuo D, et al. Pathogenicity Evaluation and Virulence Gene Identification of an Attenuated Duck Enteritis Virus. Microorganisms. 2025. URL: https://pubmed.ncbi.nlm.nih.gov/41304222/

[17] Wan J, Zhu Y, Xu X, et al. [Development of a rapid detection method for a virulent strain of duck enteritis virus based on real-time fluorescence recombinase polymerase amplification]. Sheng Wu Gong Cheng Xue Bao. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/42009547/

[18] Dai Y, Hu X, Zhong Y, et al. Rapid Detection of Duck Enteritis Virus with MIRA, MIRA-qPCR, and MIRA-LFD Assays. Pathogens. 2025. URL: https://pubmed.ncbi.nlm.nih.gov/41156591/

[19] Yan L, Song Y, Zhai T, et al. Establishment of a Visual Gene Chip Method for the Simultaneous Detection of Seven Waterfowl Virus Pathogens. Viruses. 2025. URL: https://pubmed.ncbi.nlm.nih.gov/40143287/

[20] Bhattacharya S, Kumar S. Piperazine inhibits Anatid herpesvirus-1 infection by possible modulation of host cytokines. Microb Pathog. 2025. URL: https://pubmed.ncbi.nlm.nih.gov/40484049/

[21] Jia W, Wang A, Wu Z, et al. Construction and characterization of recombinant duck enteritis virus expressing duck hepatitis A virus 3 immunogenic genes. Poult Sci. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/41850054/

[22] Chen L, Zhu Y, Yun T, et al. In vitro expression of the goose astrovirus Cap protein delivered with a duck enteritis virus vector. BMC Vet Res. 2025. URL: https://pubmed.ncbi.nlm.nih.gov/40317044/

[23] Liu J, Wang Y, Tang N, et al. CRISPR/Cas9-edited duck enteritis virus expressing Pmp17G of Chlamydia psittaci induced protective immunity in ducklings. Pathog Dis. 2024. URL: https://pubmed.ncbi.nlm.nih.gov/39400699/

[24] Zhao Y, Ma Q, Jiao C, et al. Recombinant duck enteritis virus harboring the hemagglutinin genes of influenza virus rapidly induces specific cellular immunity in ducks. J Virol. 2026. URL: https://pubmed.ncbi.nlm.nih.gov/41467842/

[25] Jia WF, Wang AP, Wu Z, et al. Current status of recombinant duck enteritis virus vector vaccine research. Front Vet Sci. 2025. URL: https://pubmed.ncbi.nlm.nih.gov/39974164/

[26] Abdulrahim Y, You Y, Wang L, et al. Evaluation of Tissue Tropism and Horizontal Transmission of a Duck Enteritis Virus Vectored Vaccine in One-Day-Old Chicken. Viruses. 2024. URL: https://pubmed.ncbi.nlm.nih.gov/39599796/

[27] Siedlecka M, Chmielewska-Władyka M, Kublicka A, et al. Goose parvovirus, goose hemorrhagic polyomavirus and goose circovirus infections are prevalent in commercial geese flocks in Poland and contribute to overall health and production outcomes: a two-year observational study. BMC Vet Res. 2025. URL: https://pubmed.ncbi.nlm.nih.gov/40155934/

[28] Abdulrahim Y, You Y, Wang L, et al. Correction: Abdulrahim et al. Evaluation of Tissue Tropism and Horizontal Transmission of a Duck Enteritis Virus Vectored Vaccine in One-Day-Old Chicken. Viruses 2024, 16, 1681. Viruses. 2024. URL: https://pubmed.ncbi.nlm.nih.gov/39772278/

[29] Zhirov D, Dubovitskiy N, Derko A, et al. First detection and diversity of astroviruses in wild migratory birds of Sakhalin Island, North Pacific. Virus Genes. 2025. URL: https://pubmed.ncbi.nlm.nih.gov/39729281/

[30] Dai Y, Zhong Y, Xu F, et al. Development and evaluation of three multienzyme isothermal rapid amplification assays for fowl adenovirus serotype 4. Poult Sci. 2024. URL: https://pubmed.ncbi.nlm.nih.gov/39504832/