Neosporosis : An Infectious Disease

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Neosporosis is an infectious disease prominent in both livestock and companion animals. Neosporosis was first discovered in dogs in Norway in 1984, when it caused neuromuscular degeneration that lead to hind limb paralysis. Due to the similarity of Neospora caninum to Toxoplasma gondii, neosporosis was misidentified as toxoplasmosis for many years. The two share similar life cycles and structure but vary when it comes to hosts. N. caninum thrives in cattle, dogs and related canids whereas T. gondii thrives in humans, sheep, and goats, and felids (usda). In 1988, the description of the new genus and species Neospora caninum was released, ending the misdiagnosis. Since then, neosporosis has become a serious disease for dogs and cattle…show more content…
Natural infections have been observed in dogs, cattle, sheep, goats, horses, and deer. In the lab, researchers have successful induced infections in mice, rats, dogs, foxes, goats, cats, sheep, coyotes, pigs, gerbils, rabbits, sheep, and cattle (a review). This coccidian parasite is spread transplacentally with vertical route being the most common source of transmission in cattle. This route is made possible by N. caninum’s life cycle that consists of three infectious stages: tachyzoites, tissue cysts, and oocysts. The dog (the definitive host) ingests the tissue cysts found in the intermediate host and when these tissue cysts reach the gut the parasite starts a new life cycle. This cycle produces unsporulated oocytes which are then excreted in the dog’s feces, and absorbed into the environment (soil, water, and feed). In the environment the oocysts quickly sporulate. Herbivores, such as a cow, then ingest the contaminated feed or water and become infected. Systemic Effects: Etiology and Impacts Dams infected with N. caninum pass on tachyzoites through the placenta, infecting the fetus (Neosporosis in cattle Jp). Inside the fetus, the tachyzoites invade neural stem cells, transforming them into bradyzoites which allows them to slowly divide and reproduce asexually. These “bradyzoites form tissue cysts around themselves for protection” and lay dormant until the immune system of the fetus is suppressed. When this occurs they
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