Rapid communication: Dogs are definitive hosts of Neospora caninum

https://doi.org/10.1016/S0020-7519(98)00138-6Get rights and content

Abstract

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 μm 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.

Section snippets

Neospora caninum (Apicomplexa: Sarcocystidae) is a protozoan that infects domestic and wild canids, ruminants, and horses 1, 2, 3. Neosporosis is economically important in cattle, and is the most commonly diagnosed cause of bovine abortion in California, the Netherlands, and New Zealand 1, 4, 5. The parasite exists on at least six continents 1, 2, 3. To date, N. caninum is the only recognised species in the genus; canine and bovine isolates appear to be identical [6].

Prior to its description in

Acknowledgements

This research was supported in part by USDA-NRICGP grant 96-02532. The authors thank Jennifer D. Tranas, S. K. Shen, O. C. H. Kwok, Diane Hawkins-Cooper, Virginia Viers, Kathy Lowe and Jill Songers for technical assistance, and Catherine A. Jones and Wendi R. Wilson for animal care.

References (24)

  • JP Dubey et al.

    Vet Parasitol

    (1996)
  • LT Huong et al.

    Vet Parasitol

    (1998)
  • J Holmdahl et al.

    Parasitol Today

    (1997)
  • JS Barber et al.

    J Parasitol

    (1997)
  • ML Anderson et al.

    J Am Vet Med Assoc

    (1995)
  • RN Thornton et al.

    N Zeal Vet J

    (1991)
  • JP Dubey et al.

    J Am Vet Med Assoc

    (1988)
  • Current WL, Upton SJ, Long PL. Taxonomy and life cycles. In: Long PL, editor. Coccidiosis of man and domestic animals....
  • MM McAllister et al.

    Am J Vet Res

    (1998)
  • DS Lindsay et al.

    J Parasitol

    (1996)
  • DG Baker et al.

    J Parasitol

    (1995)
  • JP Dubey et al.

    J Am Vet Med Assoc

    (1988)
  • Cited by (954)

    • Neosporosis in Argentina: Past, present and future perspectives

      2023, Veterinary Parasitology: Regional Studies and Reports
    • Molecular detection of Neospora caninum in chicken meat and eggs in Iran

      2023, Veterinary Parasitology: Regional Studies and Reports
    • Parasites of the musculoskeletal system

      2023, Organ-Specific Parasitic Diseases of Dogs and Cats
    View all citing articles on Scopus
    View full text