Endemic aleutian disease

Aleutian disease (AD) is a common global disease in farmed mink caused by infection with Aleutian disease virus (ADV). This thesis investigated the use of ADV antibody ELISA as a tool to reduce the impact on welfare and reproduction of mink in ADV endemic areas. First, two ELISA systems were compared. The ELISA system based on VP2 antigen detected ADV antibodies in serum with high sensitivity and specificity when compared to counter immunoelectrophoresis (CIEP). In contrast, the ELISA system based on ADV-G antigen did not perform as well and had a low sensitivity compared to CIEP. The VP2 ELISA also detected antibodies to ADV in dried whole blood eluted from filter paper (DBS) with a preserved high sensitivity and specificity and with good correlation to antibody levels in serum. The ADV antibody levels were comparable over a period of two weeks which may correspond to the time needed to sample all mink in large herds. The correlation between the estimated antibody level in DBS and the ratio of albumin: gamma globulins (A:γG) in serum in individual mink was generally high but superior for DBS compared to serum samples from the same mink. The use of DBS VP2 ELISA was therefore concluded to be the preferable indirect method for estimating hypergammaglobulinemia in mink. Further, the association between the reproductive performance and the antibody level was also investigated at an individual level. For the primiparous mink, the risk of being barren was associated with the AD status prior to mating. Diseased mink had a higher risk of being barren than non-diseased mink. In addition, the litter size of the primiparous non-barren female mink was also associated with the AD status prior to mating, where diseased mink had a 5% reduced litter size. For older mink, on the other hand, no difference due to AD status was found but they had approximately 5 % larger litters than primiparous mink irrespective of AD status. To aid selection of future breeders, the female mink could be categorized into two or three different disease categories depending on the mean antibody level in the herd. Selection of healthy mink for breeding can be expected to be beneficial for the welfare of the female mink, the overall breeding performance of the herd, as well as the production economy