Transmission Dynamics of Aleutian Mink Disease Virus on a Farm Under Test and Removal Scheme

Dose response of black American mink to Aleutian mink disease virus

“…5,6 It has long been known that some AMDVinfected mink do not succumb to the disease and live healthy and productive lives. [7][8][9][10][11][12] It was for this reason that selection for tolerance to AD was adopted by many mink farmers in Nova Scotia, Canada, after an AMDV outbreak in 2012 and 2013 (unpublished data). Selection for tolerance to AD has also gained momentum in other counties.…”

“…Mink are commonly evaluated for tolerance on naturally infected farms where the most likely scenario is exposure to low doses of the virus as a result of the slow rate of horizontal AMDV transmission. 11,12,16 Although all mink on chronically infected farms ultimately become exposed to the virus, the time for the establishment of infection under natural conditions is unpredictable. Furthermore, to establish infection, the amount of virus intake must overwhelm the host's defense mechanism.…”

“…The immune system of some mink seems to be capable of curtailing the establishment of infection or producing detectable levels of antibodies when exposed to low viral doses, [17][18][19] which is manifested as seronegative mink on chronically infected farms. 9,12,13,20 It is important to know whether the presence of seronegative mink on infected farms was the result of genetic differences or because the level of the virus to which they were exposed was too low. Interestingly, when pairs of littermates were kept in the same cage for several months, only one turned seropositive in some cages, 9,12 which could suggest that viral dose might have been a more determining factor than animal genetic makeup.…”

“…9,12,13,20 It is important to know whether the presence of seronegative mink on infected farms was the result of genetic differences or because the level of the virus to which they were exposed was too low. Interestingly, when pairs of littermates were kept in the same cage for several months, only one turned seropositive in some cages, 9,12 which could suggest that viral dose might have been a more determining factor than animal genetic makeup. It is thus important to understand the effects of various doses of any AMDV strain on antibody titer and viremia at the time when replacement mink are selected for tolerance (November and December).…”

Effects of dietary kelp (Ascophylum nodosum) supplementation on survival rate and reproductive performance of mink challenged with Aleutian mink disease virus

“…In the present study, pre-weaning mortality rates in mink fed the three diets were higher than 25.8% kit mortality from birth to weaning at 4 wk of age on two AMDVinfected farms in Argentina (Martino and Villar 1990). Pre-weaning mortality rates were also higher than those of uninfected mink, which ranged between 11.3% and 27.4% (Schneider and Hunter 1993;Malmkvist et al 1997;Hansen et al 2010;Farid et al 2018;Karimi et al 2018). The lack of any effect of 1.5% kelp on pre-weaning survival was probably partly the result of significantly greater litter size in this group which negated the possible positive effects of kelp supplementation.…”