Biological characteristics of laboratory rats under experimental BLV infection

Enzootic bovine leukemia has been an urgent problem of veterinary medicine both in the Russian Federation and abroad for more than a hundred years. A number of aspects have been studied in depth, but there are also those that require additional research. Development of an adequate laboratory model for BLV infection studding, among them. Preliminary studies have shown that infection laboratory rats with BLV is accompanied by clinical, biochemical and morphological changes in blood correlating with the same in cattle, signs of immune suppression, impaired immunological reactivity of the organism, and morphofunctional changes at the immunocompetent cells level. In this regard, the analysis of provoked by these dysfunctions disorders, reflected in changes in the morphometric characteristics of both the whole organism and individual organs is of particular interest. The aim of our research was studying a dynamics of body weight and the internal organs relative weight in laboratory rats under experimental infection with BLV. The dynamics of weight indicators of laboratory rats infected with BLV was characterized by a pronounced tendency to their increase, followed by a decrease down to negative values. The opposite tendency was noted for such internal organs of experimental animals as spleen, liver, lungs and kidneys. At first, the relative weight decreased to a different extent, then increased with different dynamics in groups with the exclusion of a heart. Its relative mass decreased and did not increase until the experiment termination. Our data correlate with number of the authors’ opinion that while BLV infection organs relative mass changes as a result of inflammatory, proliferative, dystrophic and atrophic processes.