Submitted to: Journal of Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 6, 1995
Publication Date: N/A
Interpretive Summary: Infection by the protozoan parasite, Neospora caninum causes paralysis and death in dogs and abortion in livestock. Its life cycle and sources of infection are unknown. The transplacental route of infection is the only proven mode of transmission. It is not known if N. caninum can cause abortion in dogs. Scientists at the Beltsville Agricultural Research Center and the Auburn University, Alabama have found that N. caninum causes fetal death and resorption in bitches infected during the early part of gestation. These findings will be helpful to dog breeders and veterinary pathologists.
Herein we report the development of a canine model to examine transplacental and/or transmammary transmission of Neospora caninum. Six pregnant bitches were experimentally infected with N. caninum on day 21 of gestation. One bitch successfully delivered a litter of 3 live pups. These pups showed slight proprioception deficits, increased muscle tone and spasticity in both pelvic limbs; however, N. caninum was neither demonstrated by bioassay in cell culture, nor seen in histological sections of tissues from these pups. The remaining 5 bitches aborted. Neospora caninum was isolated from tissues of 4 of the experimentally infected bitches and pups from 2 of the miscarried litters. Experimental infections of 2 litters of 5-day-old nursing pups produced variable results. Neospora caninum was isolated from 2 of 2 inoculated pups in 1 litter and 3 of 6 inoculated pups in the second litter.