Abstract
Neospora caninum is a newly described coccidian parasite which has been found in various species such as the dog, cattle, horse, sheep and goat. Morphologically it resembles Toxoplasma gondii with which it is related (Holmdahl et al. 1994), and with which it has earlier been confused. The life cycle of N caninum is only partially known. Tachyzoites and tissue cysts are the only known stages of the parasite, and transplacental transmission is the only known route of infection. Subclini-cally infected dams can transmit the parasite to their fetuses and successive offspring from the same mother might be born infected (Dubey et al. 1990b). Clinical neosporosis is mostly seen in pups or young dogs, and the majority or all pups in a litter are often affected. The disease is characterized by ascending paralysis of the legs, with the hind legs more severely affected than the front legs, paralysis of the jaw, difficulty in swallowing and muscle flaccidity and atrophy (Dubey 1992, Dubey & Lindsay 1993). Fatal infections with N caninum in dogs have been reported from many countries, e.g. Norway (Bjerkäs & Presthus 1988), USA (Dubey et al. 1988), Sweden (Uggla et al. 1989a,b) and the United Kingdom (Dubey et al. 1990a). Serological surveys for antibodies to N. caninum in dogs from Kansas, USA and England have shown a prevalence of 2 and 13%, respectively (Lindsay et al. 1990, Trees et al. 1993).
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Acknowledgments
The authors are grateful to Dr. J.P. Dubey for providing the NC-1 isolate of N. caninum, to Dr. J.M. Holmdahl for maintaining the parasites in cell culture, and to Ms Britt-Louise Ljungström for technical assistance. Financial support was obtained from Agria Insurances Inc. and in part by the Swedish Council for Forestry and Agricultural Research. The study was a part of the EU collaboration COST 820.
References
- Bjerkås I, Presthus J. Immuno-histochemical and ultrastructural characteristics of a cyst-forming sporozoon associated with encephalomyelitis and myositis in dogs. Acta path, microbiol. immunol. scand. 1988;96:445–454. doi: 10.1111/j.1699-0463.1988.tb05328.x. [DOI] [PubMed] [Google Scholar]
- Björkman C, Lunden A, Holmdahl J, Barber J, Trees A, Uggla A. Neospora Caninum in dogs: detection of antibodies by ELISA using an iscom antigen. Parasite Immunol. 1994;16:643–648. doi: 10.1111/j.1365-3024.1994.tb00320.x. [DOI] [PubMed] [Google Scholar]
- Dubey JP. A review of Neospora caninum and NeosporaAike infections in animals. J. protozool. Res. 1992;2:40–52. [Google Scholar]
- Dubey JP, Carpenter JL, Speer CA, Topper MJ, Uggla A. Newly recognized fatal protozoan disease of dogs. J. Amer. vet. med. Assoc. 1988;192:1269–1285. [PubMed] [Google Scholar]
- Dubey JP, Higgins RJ, Smith JH, O’Toole TD. Neospora caninum encephalomyelitis in a British dog. Vet. Rec. 1990;126:193–194. [PubMed] [Google Scholar]
- Dubey JP, Koestner A, Piper RC. Repeated transplacental transmission of Neospora caninum in dogs. J. Am. vet. med. Assoc. 1990;197:857–860. [PubMed] [Google Scholar]
- Dubey JP, Lindsay DS. Neosporosis. Parasitology Today. 1993;9:452–458. doi: 10.1016/0169-4758(93)90099-2. [DOI] [PubMed] [Google Scholar]
- Holmdahl JM, Mattssson JG, Uggla A, Johansson K-E. The phylogeny of Neospora caninum and Toxoplasma gondii based on ribosomal RNA sequences. FEMS Microbiology Letters. 1994;119:187–192. doi: 10.1111/j.1574-6968.1994.tb06887.x. [DOI] [PubMed] [Google Scholar]
- Lindsay DS, Dubey JP, Upton SJ, Ridley RK. Serological prevalence of Neospora caninum and Toxoplasma gondii in dogs from Kansas. J. hel-minthol. Soc. Wash. 1990;57:86–88. [Google Scholar]
- Trees AJ, Guy F, Tennant BJ, Balfour AH, Dubey JP. Prevalence of antibodies to Neospora caninum in a population of urban dogs in England. Vet. Rec. 1993;132:125–126. doi: 10.1136/vr.132.6.125. [DOI] [PubMed] [Google Scholar]
- Uggla A, Dubey JP, Funkquist B, Segall T. Fatal Neospora caninumAntektion. hos riesenschnau- zer. (Fatal Neospora caninum infection in a dog) Svensk Vet.Tidn. 1989;41:271–274. [Google Scholar]
- Uggla A, Dubey JP, Lundmark G, Olson P. Encephalomyelitis and myositis in a boxer puppy due to a NeosporaAikc infection. Vet. Parasitol. 1989;32:255–260. doi: 10.1016/0304-4017(89)90125-8. [DOI] [PubMed] [Google Scholar]
- Uggla A, Mattson S, Juntti N. Prevalence of antibodies to Toxoplasma gondii in cats, dogs and horses in Sweden. Acta vet. scand. 1990;31:219–222. doi: 10.1186/BF03547564. [DOI] [PMC free article] [PubMed] [Google Scholar]