Neospora caninum

Neospora caninum
Neospora caninum
Systematics
without rank: Conoidasida without rank: Coccidia (Coccidia) without rank: Isosporidae Family : Sarcocystidae Genre : Neospora Type : Neospora caninum
Scientific name
Neospora caninum
JP Dubey et al., 1988

Neospora caninum is a parasitic unicellular organism whose final hosts are dogs, wolves, dingoes and coyotes. It occurs worldwide and is the causative agent of neosporosis . The parasite was first observed in Norway in 1984. It was first described as a separate species in 1988.

In its appearance, N. caninum is similar to the toxoplasmosis pathogen Toxoplasma gondii . The tachyzoites are 3–8 µm × 1–5 µm in size and have a crescent shape. The cysts are round or spindle-shaped, not chambered, up to 110 µm in size and contain several hundred bradyzoites . The bradyzoites are 6–10 µm × 1–1.8 µm in size.

Development cycle

The ultimate hosts become infected primarily through the ingestion of cysts in the meat of intermediate hosts. From this, bradyzoites are released in the small intestine, which penetrate the intestinal epithelial cells and multiply there by means of schizogony and form schizonts. It is believed that the schizonts give rise to macro- and microgametes that combine to form oocysts that are excreted in the dog's feces. In the outside world, the oocysts sporulate and form two sporocysts with four sporozoites . Infection of intermediate hosts occurs through the ingestion of sporulated oocysts through contaminated food. Cattle, other ruminants and numerous other herbivores act as intermediate hosts, but also dogs themselves. In the intermediate host, the sporozoites penetrate intestinal epithelial cells and later into many other cell types, where they develop into tachyzoites, which reproduce asexually via endodyogeny . In cattle, the parasite can cross the placental barrier and infect the fetus. In the first and second trimester, this usually leads to miscarriages, while infections in the third are usually symptomatic. However, if they later become pregnant themselves, female animals can pass the pathogen on to their unborn offspring.

Individual evidence

1. Jump up ↑ JP Dubey, MC Jenkins, C. Rajendran, K. Miska, LR Ferreira, J. Martins, OC Kwok, S. Choudhary: Gray wolf (Canis lupus) is a natural definitive host for Neospora caninum. In: Veterinary parasitology. Volume 181, number 2-4, September 2011, ISSN  1873-2550 , pp. 382-387, doi : 10.1016 / j.vetpar.2011.05.018 , PMID 21640485 .
2. ↑ JS King, J. Slapeta, DJ Jenkins, SE Al-Qassab, JT Ellis, PA Windsor: Australian dingoes are definitive hosts of Neospora caninum. In: International journal for parasitology. Volume 40, Number 8, July 2010, ISSN  1879-0135 , pp. 945-950, doi : 10.1016 / j.ijpara.2010.01.008 , PMID 20149793 .
3. ↑ Gondim, LFP; MM McAllister; WC Pitt; DE Zemlicka: Coyotes (Canis latrans) are definitive hosts of Neospora caniinum. In: International Journal for Parasitology 34 (2004): 159-161.
4. ↑ JP Dubey, JL Carpenter, CA Speer, MJ Topper, A. Uggla: Newly recognized fatal protozoan disease of dogs. In: Journal of the American Veterinary Medical Association. Volume 192, Number 9, May 1988, ISSN  0003-1488 , pp. 1269-1285, PMID 3391851 .
5. ↑ Thomas Schnieder: Veterinary Parasitology . Georg Thieme, 2006, ISBN 9783830441359 , p. 148.
6. ^ Alan Gunn, Sarah Jane Pitt: Parasitology: An Integrated Approach . John Wiley & Sons, 2012, ISBN 9780470684245 , pp. 58-59.