Sarcocystis infection in red deer (Cervus elaphus) with eosinophilic myositis/fasciitis in Switzerland and involvement of red foxes (Vulpes vulpes) and hunting dogs in the transmission

Abstract

Red deer (Cervus elaphus) carcasses showing grey-greenish discolouration have been increasingly observed in the canton of Grisons, Switzerland. We investigated whether Sarcocystis infections were associated with this pathology, and whether wild and domestic canids were involved in their transmission. Meat from affected red deer (n = 26), faeces and intestines from red foxes (Vulpes vulpes) (n = 126), and faeces from hunting dogs (n = 12) from the region, were analysed. Eosinophilic myositis and/or fasciitis were diagnosed in 69% of the deer, and sarcocysts were observed in 89% of the animals. Molecular typing targeting a ~700bp variable region of the 18S rRNA gene revealed Sarcocystis hjorti in 73%, S. venatoria/S. iberica in 54%, S. linearis/S. taeniata in 12%, S. pilosa in 8% and S. ovalis in 4% of the deer samples. No inflammatory changes were observed in red deer carcasses with normal appearance (n = 8); however, sarcocysts were observed in one sample, and S. hjorti, S. venatoria/S. iberica or S. silva DNA was detected in five samples. Sarcocystis oocysts/sporocysts were observed in 11/106 faecal and 6/20 intestinal fox samples, and in 2/12 canine samples. Sarcocystis tenella (n = 8), S. hjorti (n = 2), S. gracilis (n = 2), and S. miescheriana (n = 1) were identified in foxes, and S. gracilis (n = 2), S. capreolicanis (n = 1) and S. linearis/S. taeniata (n = 1) in dogs. This study provides first molecular evidence of S. pilosa and S. silva infection in red deer and S. linearis/S. taeniata in dogs and represents the first record of S. ovalis transmitted by corvids in Central Europe. Although Sarcocystis species infecting red deer are not regarded as zoonotic, the affected carcasses can be declared as unfit for human consumption due to the extensive pathological changes.

Keywords: Dog (Canis familiaris); Molecular identification; Myositis/fasciitis; Red deer (Cervus elaphus); Red fox (Vulpes vulpes); Sarcocystis.

Graphical abstract

Fig. 1

A–B: Grey-greenish discolouration of muscle and fasciae from red deer. (Photo: E. Eggenberger) (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)

Fig. 2

A–C: Extensive diffuse eosinophilic infiltration along connective tissue in fascia and skeletal fore limb muscle from a red deer showing grey-greenish discolouration of the carcass (Deer 7), characterized by eosinophilic leukocytes (black arrows) and lymphocytes; A: Sarcocystis cyst (“sarcocyst”)(arrowhead) and eosinophilic leucocytes (black arrows), bar = 10 μm. B: intramuscular blood vessel with hypertrophied media, bar = 20 μm. C: intramuscular eosinophilic infiltration (black arrows) along myofibers, bar = 10 μm. Haematoxylin and eosin (HE) staining. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)

figs1

Phylogenetic tree for Sarcocystis species based on partial 18S rRNA sequences of 215 Taxa obtained in the present study and 61 GenBank® reference sequences according to Table 3, Table 4, inferred using the neighbour-joining method.