Sarcocystis spp. infection in roe deer (Capreolus capreolus) from the north-west of Spain

Samples of heart, oesophagus and diaphragm muscle from 132 roe deer (Capreolus capreolus) hunted in game reserves from Lugo province (north-western Spain) were examined to determine the prevalence of Sarcocystis infection. Sarcocysts were examined by light (LM) and transmission electron microscopy (TEM). The overall prevalence of infection was 85.6%, with a density of 15 +/- 16.8 cysts/g of muscle. The highest prevalence was observed in the large preserve in Ancares (97.3%) compared to that of the smaller reserves (81.1%). Size and shape differences were observed in the sarcocysts from the different muscular organs. The highest density of infection was in the heart, particularly to the inner part of the myocardium. LM distinguished two types of sarcocysts: thin-walled cysts present in all the positive organs and a thick-walled cyst, identified as S. hofmanni, found in the oesophagus of one animal. By TEM only one type of cyst wall, having a thin primary wall that formed folded hair-like protrusions, could be differentiated. Ultrastructural features of the cyst wall demonstrated that this species corresponds with the unnamed species Sarcocystis sp.