[4] The clinical signs of DEV "vary with virulence of virus strain, species, sex, and immune system status" of the host.

Duck enteritis virus can only infect birds of the family Anatidae of the order Anseriformes, with the possible exception of coots.

[9] Diagnosis can usually be made based on the clinical signs and postmortem findings: On post-mortem, petechial haemorrhage in the conjunctivae, mucous membranes, trachea, syrinx and intestine are pathognomonic for DEV.

Diagnosis can also be confirmed with presence of virus inclusion bodies in tissues or a positive immunohistochemical staining for viral antigen.

[7] If host organisms survive primary infection, they enter a latent stage lasting up to 4 years.

Virus particles can be shed by the latent host in shared water or through direct contact (horizontal transmission), contributing to on-going epizootics.

Examples of physiological cues include "stress of migration, breeding season, [and] social interaction.

"[7] Primary latency sites in carries are the trigeminal ganglion, lymphoid tissue, and blood lymphocytes.

[4] Viral replication causes an increase in vascular permeability, which leads to the lesions and hemorrhaging of organs, namely the liver, spleen, thymus, and bursa of Fabricius.

[7] Typically viral replication begins in the digestive track and moves to bursa of Fabricuis, thymus, spleen, and liver.

[11] Duck enteritis virus, similar to other herpesviruses, has a linear double stranded DNA genome.

[13] Common elements of herpesviruses include a "DNA core, icosahedral capsid, tegument, and envelope.

[11] After entering the host organism a virion begins the process of replication by first attaching to cells using glycoprotein spikes.

[4] Similar Alphaviruses use gC protein to aid in binding the virion to the cell and gD to stabilize it, if required.

[4] Envelope fusion with the plasma membrane of the host cell causes separation of the nucleocapsid from viral DNA and proteins.

[4] The 1973 Lake Andes, South Dakota DEV outbreak was the other major incidence of the disease in the United States.