Recovery of Sarcocystis gigantea sporocysts from cat faeces

A method for the mass recovery of S. gigantea sporocysts from cat faeces involving homogenisation and centrifugation in water, passage through 250- and 53-microns sieves and floatation in 1.2 SG NaCl solution, is described. An examination of the various processes involved in this procedure showed that the greatest yields were obtained when a proportion of faeces to floatation medium of 1:20 and centrifugation at 6000 X g for at least 5 min was used. Ninety-six per cent of the sporocysts recovered were obtained from the first centrifugation in aqueous NaCl solution (SG 1.2). Although neither sieving nor additional washing of homogenised samples prior to floatation significantly affected sporocyst recovery, both reduced the amount of debris present. A considerable reduction in the amount of debris resulted from feeding infected cats on tinned fish rather than tinned meat. The addition of CCl4 to the NaCl solution also improved sporocyst purity but with a marked reduction in the numbers recovered.