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In naive cats, ''Toxoplasma gondii'' undergoes an enteroepithelial life cycle. Cats ingests intermediate hosts containing tissue cysts, which release bradyzoites in the gastrointestinal tract. The bradyzoites penetrate the small intestinal epithelium and sexual reproductio ensues, eventually resulting the production of oocysts. Oocysts are passed in the cat's faeces and sporulate to become infectious once in the environment. These can then be ingested by other mammals, including sheep.
In naive cats, ''Toxoplasma gondii'' undergoes an enteroepithelial life cycle. Cats ingests intermediate hosts containing tissue cysts, which release bradyzoites in the gastrointestinal tract. The bradyzoites penetrate the small intestinal epithelium and sexual reproductio ensues, eventually resulting the production of oocysts. Oocysts are passed in the cat's faeces and sporulate to become infectious once in the environment. These can then be ingested by other mammals, including sheep.
When sheep ingest oocysts, ''T.gondii'' intiates extraintestinal replication. This process is the same for all hosts, and also occurs when carnivores ingest tissue cysts in other animals. Sporozoites (or bradyzoites, if cysts are consumed) are released in the intestine to infect the intestinal epithelium where they replicate. This produces tachyzoites, which reproduce asexually within the infected cell. When the infected cell ruptures, tachyzoites are released and disseminate via blood and lymph to infect other tissues. Tachyzoites then replicate intracellularly and, if the cell does not burst, they eventually encyst and persist for the life of the host.
When sheep ingest oocysts, ''T.gondii'' intiates extraintestinal replication. This process is the same for all hosts, and also occurs when carnivores ingest tissue cysts in other animals. Sporozoites (or bradyzoites, if cysts are consumed) are released in the intestine to infect the intestinal epithelium where they replicate. This produces tachyzoites, which reproduce asexually within the infected cell. When the infected cell ruptures, tachyzoites are released and disseminate via blood and lymph to infect other tissues. Tachyzoites then replicate intracellularly again and the process continues until the host becomes immune or dies. If the infected cell does not burst, tachyzoites eventually encyst as bradyzoites and persist for the life of the host. These tissue cysts are a source of infection for carnivorous animals.
==Signalment==
==Signalment==