The experimental reproduction of thrombocytopenic purpura in piglets.

Two gilts, non-affected members of a litter which had been affected with thrombocytopenic purpura were mated to a boar which was an affected member of the same litter. During pregnancy the gilts were injected with pure thrombocyte suspensions from the boar. Antibodies to the boar's thrombocytes were demonstrated in the sera of both gilts and also in samples of their colostrum at each parturition. The piglets produced from these matings had normal thrombocyte counts at birth but a proportion of them developed thrombocytopenia and purpura similar to that seen in natural cases within a few hours of receiving colostrum. However, despite the fact that this condition was observed in three litters from each of the gilts, a secondary thrombocytopenia at 10 to 14 days of age, characteristic of the naturally occurring condition, was only observed in two piglets in one litter.