**4.3 Pathogenesis**

Sarcocystis spp, are protozoon parasites with a requisite two-host life cycle. Sexual reproduction phase occur in the intestine of a carnivore (dogs, cats) later, cysts in the muscles of cattle, sheeo or goats. Sporocysts are shedded by carnivore's feces and then ingested by cattle, sheep, or goats. Then sporocysts hatch in the ruminant small bowel and invade the vascular endothelium during three phases of asexual reproduction. After third phase, merozoites enter the ruminant's muscle tissue and encyst as sarcocysts (Smith and George, 2009; Reilly et al., 2002).

Investigation of giemsa-stained blood smears and lymph node biopsy will reveal piroplasms in erythrocytes and schizonts in lymphocytes. For diagnosis, indirect fluorescent antibody test (IFAT) and indirect enzyme-linked immunosorbent assay (ELISA) are the most commonly used techniques. The ELISA tests is more sensitive than IFAT (Taylor et al., 2007;

Buparvaquone is the most effective drug and the recommended dose in cattle, sheep and

In control of the disease use of genetically resistant breed, a judicious and selective application of acaricides at 3- week intervals and the use of vaccines are recommended

Sarcocystosis caused by Sarcocystis species in cattle, sheep and goats. The names of Sarcocystis species are according to their intermediate and final hosts (Taylor et al., 2007;

**Definitive host Geographic** 

**distribution** 

goat is 2.5mg /kg BW (Taylor et al., 2007; Radostits et al., 2008).

Radostits et al., 2008). The list of sarcocystis species is shown in table 3.

**host**

Sarcocystosis occur in all of countries (Taylor et al., 2007; Radostits et al., 2008).

Sarcocystis spp, are protozoon parasites with a requisite two-host life cycle. Sexual reproduction phase occur in the intestine of a carnivore (dogs, cats) later, cysts in the muscles of cattle, sheeo or goats. Sporocysts are shedded by carnivore's feces and then ingested by cattle, sheep, or goats. Then sporocysts hatch in the ruminant small bowel and invade the vascular endothelium during three phases of asexual reproduction. After third phase, merozoites enter the ruminant's muscle tissue and encyst as sarcocysts (Smith and

S. bovicanis S. cruzi Cattle Dog, wolf Worlwide S. bovifelis S. hirsuta Cattle Cat Worlwide S. bovihominis S. hominis Cattle Human Worlwide S. ovicanis S. tenella Sheep Dog, fox Worlwide S. ovifelis S. gigantica Sheep Cat Worlwide S. capracanis - Goats Dog, wolf Worlwide S. hircicanis - Goats Dog Worlwide S. hircifelis S. moulei Goats cat Worlwide

**Species Synonyms Intermediate** 

Table 3. Sarcocystis species (Sarcocystosis)

**3.5 Diagnosis** 

Radostits et al., 2008).

(Radostits et al., 2008).

**4. Sarcocystosis** 

**4.2 Epidemiology** 

**4.3 Pathogenesis** 

George, 2009; Reilly et al., 2002).

**4.1 Etiology** 

**3.6 Treatment and control** 

Fig. 4. Sarcocystis spp. bradizoit smear, impression smear, Giemsa staining, immersion objective
