Canine distemper in pigs
Canine distemper virus (CDV) has a wide host range in both natural and experimental conditions. Most of terrestrial carnivores belonging to the families like Canidae (dogs, foxes, coyotes, wolves and jackals), Mustelidae (weasels, ferrets, minks, skunks, badgers, stoats, martens and otters), Procyonidea (raccoons, panda, cat ferrets and kinkajous), Ursidae (mongooses), Hyaenidae, Ailuridae or Viverridae die or manifest clinical signs of the disease when infected with CDV. Furthemore, the members of Felidae (cats, lions, tigers and leopards) and Suidae (domestic pigs) families were also found to be susceptible to CDV infection, though the clinical signs are not manifested generally. This work is aimed at studying the special characteristics of an inapparent CDV infection in pigs. An intranasal challenge with a virulent CDV strain Snyder Hill showed that compared to the initial level, the blood leukocyte concentrations on days 4 and 7 decreased by 2,8 and 3,1 times, and the proliferative response of lymphocytes to T-mitogen decreased by 27,7 and 15,8 times and to B-mitogen by 37,4 and 24,9 times, respectively. The leukocyte concentrations in blood and the functional activity levels of T- and B-lymphocytes were restored only on days 21 to 35. Using a passive hemagglutination assay, CDV antigens in saliva samples were detected in the period from day 5 up to days 12 - 15 post infection. The highest CDV antigen concentrations in saliva were reached by day 7 or 8, with the CDV infectivity titers in swine saliva samples amounting 2,5 to 3,0 lg TCID<sub>50</sub>/cm<sup>3</sup>. Il. 2. Ref. 12.