A comparison between intraperitoneal injection and intranasal and oral inoculation of mink with Aleutian mink disease virus.

Intranasal, with (INS) and without (IN) sedation, and oral inoculation were compared with intraperitoneal (IP) injection for establishing infection with a local isolate of Aleutian mink disease virus (AMDV) in 35 American mink. Blood samples were collected on 0, 21, 36 and 56 day post-inoculation (dpi). Antiviral-antibodies and viral DNA in plasma and tissues were measured by counter-immunoelectrophoresis (CIEP) and PCR, respectively. The presence of AMDV DNA was tested by PCR in saliva, rectal and fecal samples collected on 0, 6, 10, 15, 21, 28, 36 and 56 dpi. Animals were killed at 56 dpi, samples of six organs were tested for antibody and AMDV DNA, and samples of the lungs, liver, kidneys and heart were subjected to histology. Viral DNA was detected in the spleen, lungs and lymph nodes of all inoculated mink on 56 dpi, indicating that all inoculation routes caused infection in mink. Viral DNA and antibodies were detected in plasma of all IP and INS inoculated mink by 36 dpi, but some animals which were inoculated orally or via IN remained seronegative by 56 dpi. It was concluded that INS route was the most effective method for establishing infection in mink without breaking the integrity of the animals' anatomical barriers. Viremia was short-lived in some mink, whereas antibody production persisted in seroconverted animals during the duration of the experiment. Saliva, rectal and fecal samples did not accurately detect infection. Histologic lesions of AD were observed on the four organs of most mink.