Sarcocystis Lindemanni

Synonyms: Gregarina lindemanni, Sarcocystis hominis.

Host: Man.

Location: Striated and heart muscles.

Geographic Distribution: Worldwide.

Prevalence: This name has been given to various sarcocysts of different sizes which have been found on rare occasions in man. It is extremely doubtful that man has a species of his own, and these cases were most probably infections with forms from domestic animals. The differences in size of trophozoites given in different reports bear this out (cf. Kean and Grocott, 1945).

Morphology: The cysts are up to 5.3 cm long, but are usually much smaller. Compartmentation has been described. The cyst wall is apparently smooth. The trophozoites vary in size; most are in the range of 7 to 10 by 2 to 3 u, but small ones 5 by 2 u have also been reported.

Sarcocystis Muris

Hosts: House mouse, Norway rat, black rat.

Location: Striated and heart muscles.

Geographic Distribution: Worldwide.

Prevalence: At one time this species was common in laboratory mice, but it is less so today. According to Deschiens, Levaditi and Lamy (1957), it is quite rare in laboratory mice, and they did not encounter it in laboratory rats in France during the previous 4 years.

Morphology: The cysts are elongate, range in length up to several centimeters, and are apparently not compartmented. The cyst wall is smooth. The trophozoites are 9 to 15 u long and 2.5 to 3 u wide.

Sarcocystis Cuniculi

Synonym: Sarcocystis leporum.

Hosts: Domestic rabbit, cottontail.

Location: Striated and heart muscles, especially in the hind legs, flanks and loins.

Geographic Distribution: Worldwide.

Prevalence: This species is common in cottontails. Erickson (1946) found it in 38% of 78 cottontails in Minnesota. It is apparently not common in domestic rabbits. Deschiens, Levaditi and Lamy (1957) said that it is very rare in France.

Morphology: The cysts are up to 5 mm long. They are compartmented, and their walls have a layer of cytophaneres. The trophozoites usually measure 12 to 13 by 4 to 5 u, but range in length from 6 to 16 u.

Sarcocystis Rileyi

Synonyms: Balbiania rileyi, Sarcocystis anatina, Sarcocystis horwathi, Sarcocystis gallinarum.

Hosts: Domestic duck and various wild ducks, including the mallard, black duck, gadwall, American pintail, bluewinged teal and shoveller. In addition, this species has been found in the chicken (Hawkins, 1943), sage grouse (Salt, 1958) and a number of other wild birds. Erickson (1940) listed 20 species of birds belonging to 8 orders in which Sarcocystis had been found.

Location: Striated and heart muscles, especially of the breast, neck and legs.

Geographic Distribution: Worldwide.

Prevalence: This species is especially common in surface-feeding wild ducks, but not in diving ducks. Erickson (1940) reported it from 3% of 312 wild ducks in Minnesota. It is not uncommon for hunters to bring infected birds which they have shot to a diagnostic laboratory to learn whether they are safe to eat.

Morphology: The cysts are several millimeters long and are compartmentedo The cyst wall is smooth. The trophozoites measure about 8 by 2 u.