Dogs are definitive hosts of Neospora caninum.
Dogs were investigated to determine if they are definitive hosts of Neospora caninum. Four dogs were fed N. caninum tissue cysts in infected mouse tissue, and two negative control dogs were fed uninfected mouse tissue. Dog faeces were examined daily for 30 days using a sucrose flotation technique. Three challenged dogs shed spherical to subspherical unsporulated oocysts, measuring 10 to 11 microns in diameter. Oocysts sporulated within 3 days and contained two sporocysts, each with four sporozoites. Outbred, inbred, and gamma-interferon knockout mice were inoculated with canine faecal extracts and monitored for evidence of neosporosis using a variety of morphologic, immunohistologic, serologic, and genetic analyses. Mice that received faeces from each dog observed to shed oocysts were demonstrated to have neosporosis by two or more techniques. One mouse was demonstrated to be infected with N. caninum by immunohistochemistry, ultrastructural analysis, and a species-specific PCR test. No evidence of neosporosis was observed in control animals. Based on this study, dogs are a definitive host of Neospora caninum.
University of Wyoming, College of Agriculture, Department of Veterinary Sciences, Laramie 82070, USA. mcallister@cvm.uiuc.edu
M M
MM
McAllister
J P
JP
Dubey
D S
DS
Lindsay
W R
WR
Jolley
R A
RA
Wills
A M
AM
McGuire
D000818:Animals; D000911:Antibodies, Monoclonal; D000913:Antibodies, Protozoan; D000918:Antibody Specificity; D001921:Brain / Q000469:parasitology; D002478:Cells, Cultured / Q000469:parasitology; D003048:Coccidiosis / Q000473:pathology / Q000662:veterinary*; D016054:DNA, Protozoan / Q000032:analysis; D004199:Disease Vectors; D004283:Dog Diseases / Q000469:parasitology* / Q000473:pathology; D004285:Dogs; D005243:Feces / Q000469:parasitology; D019084:Fluorescent Antibody Technique, Indirect; D006790:Host-Parasite Interactions; D007150:Immunohistochemistry; D008018:Life Cycle Stages; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D018688:Neospora / Q000276:immunology / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction
D000911:Antibodies, Monoclonal; D000913:Antibodies, Protozoan; D016054:DNA, Protozoan