Progression of experimental chronic Aleutian mink disease virus infection

Abstract

BackgroundAleutian mink disease virus (AMDV) is found world-wide and has a major impact on mink health and welfare by decreasing reproduction and fur quality. In the majority of mink, the infection is subclinical and the diagnosis must be confirmed by serology or polymerase chain reaction (PCR). Increased knowledge based on a systematically description of clinical signs, pathology and histopathology might be a tool to reduce the risk of infection from subclinically infected mink to AMDV free herds. The aim of this study was to give a histopathological description of the progression of a chronic experimental infection with a currently circulating Danish strain of AMDV, Saeby/DEN/799.1/05. These results were compared with the pathogenesis of previously published AMDV stains.ResultsThis experimental AMDV infection resulted in only decreased appetite and soft or discolored feces, primarily within the first 8 weeks after AMDV inoculation. Gross pathology revealed few and inconsistent findings mainly associated with the liver, spleen and kidneys. The majority of the AMDV inoculated wild type mink (n = 41) developed various histopathological changes consistent with AMDV infection in one or more organs: infiltrations of mononuclear cells in liver, kidney and brain, reduced density of lymphocytes and increased numbers of plasma cells in lymph nodes and spleen. Natural infection, as occurred in the sentinel sapphire mink (four of six mink), progressed similar to the experimentally inoculated mink.ConclusionsExperimental AMDV inoculation mainly resulted in subclinical infection with unspecific clinical signs and gross pathology, and more consistent histopathology appearing at any time after AMDV inoculation during the 24 weeks of observation. Thus, the observed histopathology substantiates AMDV infection and no correlation to time of inoculation was found. This confirms that diagnosing AMDV infection requires serology and/or PCR and the Saeby/DEN/799.1/05 AMDV strain results in histopathology consistent with other AMDV strains.

Dose response of black American mink to Aleutian mink disease virus

“…13 In another study, 2 of the 12 wild-type mink inoculated with AMDV showed sprinklers at 24 weeks pi, but none of the other 23 mink tested at 8-and 16-week pi showed sprinklers. 19 The observation that the incidence of sprinklers was not related to antibody titer in the current study but was detected only in the mink inoculated with 10 −4 and higher doses (Table 11), could imply that the duration of infection had the greatest effect on the incidence of sprinklers. The greater proportion of adults with sprinklers than juveniles in the current study, which was parallel with the differences between these two age groups for the prevalence of infection at 20 dpi, is further evidence that the duration of infection was an important factor in the development of sprinklers.…”

“…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.…”

EndemicSkunk amdoparvovirusin free‐ranging striped skunks (Mephitis mephitis) in California

“…Reports from 55 sick skunks submitted for histopathologic evaluation were reviewed for lymphocytic and/or plasmacytic infiltration of renal, hepatic, nervous, cardiovascular, pulmonary and endocrine organs, and pneumocyte hyperplasia as reported previously for ADV and SKAV (Alexandersen, ; Allender et al, ; Jensen, Chriel, & Hansen, ; Jensen, Hammer, & Chriel, ; LaDouceur et al, ; Pennick et al, ). Lesions were considered significant unless infiltration was classified in the report as minimal or rare.…”

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

“…The LOESS procedure and segmented regression showed that changes in body weight over time and daily gain were considerably different before and after breeding. Infection with AMDV decreases appetite (Jensen et al 2016), which was manifested as weight loss or slow rate of gain in this experiment. The significantly greater weight loss of the mink fed 1.5% kelp from day 155 (February) to 366 PI (September), which encompassed the pregnancy and lactation periods, was likely the result of significantly larger litter size of this group.…”