Letter to the Editor, regarding Bluetongue virus and canine abortions

Abstract

I read with interest the article by Dr. Ed Dubovi et al. regarding the isolation of Bluetongue virus (BTV) from canine abortions in 2011 and 2012. The authors concluded that the most likely source of the virus in the cases was due to direct infection of the pregnant dogs by the Culicoides spp. vector of BTV. The authors went on to report that there was no association between the abortions and the use of contaminated vaccines or raw meat diets. Another possibility for the occurrence of BTV in association with canine abortions was the use of fetal bovine serum (FBS), in the semen extender. All the dogs that experienced reproductive losses were bred by artificial insemination. Although the semen collected after abortions in case no. 2, from a single male, was virus isolation negative, this would not exclude the possibility that the semen extender was contaminated with BTV-containing biological fluids. Additional circumstantial evidence for a common source infection was the serologic study on the 20 dogs in the affected kennel. Eight dogs were BTV seropositive by competitive enzyme-linked immunosorbent assay. In each of the reported cases, BTV serotype 11 was isolated, which was the same serotype that had been isolated from canine abortion cases involving a vaccine grown in cell cultures using FBS contaminated with BTV-11. Whatever the source of the virus in these recent cases, it still points to the susceptibility of the pregnant dog to BTV. Precautions should be taken, especially when extraneous biological fluids are given to an animal, in particular those containing serum or serum derivatives, as they may contain adventitious viruses, which may harm the animal.3 Sincerely,