Camelostrongylus mentulatus in a roe deer from the Italian Western Alps

Camelostrongylus mentulatus is a trichostrongylid parasite which is endemic in the Middle East, North Africa and South America, where it is the dominant gastric nematode in native camelids (Abdul-Salam and Farah 1988) and frequently infects other ruminants (El-Azazy 1995). This short communication reports the finding of C mentulatus in a roe deer in Italy. A seven-month-old female roe deer (Capreolus capreolus) was found killed on a road near Oulx, in the Susa Valley (Cozie Alps, north-west Italy), in December 1996. At necropsy, no macroscopic lesions were observed apart from traumatic ones. The animal was in good condition, as shown by the presence of omental, pericardial and kidney fat, and the solid consistency of tibial bone marrow. The alimentary tract was removed and the contents of the abomasum and small intestine washed separately and sieved on wire mesh screens to a final aperture of 0-055 mm. Scrapings of the mucosae were added to the material remaining on the sieve and the resultant fluids were fixed with formaldehyde to make a 5 per cent concentration. Some fixed male parasites were observed in the fluids, and further examined in non-permanent preparations in tap water and subsequently clarified in lactophenol at 60°C for 24 hours. They were were identified according to the keys in Skrjabin and others (1952) and Gibbons and Khalil (1982). A total of 38 males of the subfamily Ostertagiinae were found in the abomasum and were all classified as C mentulatus according to the following main criteria (mean [sd] of five males measured): total length 11-845 (772) pIm; maximum width 121-2 (4.6) [m; a 2-1-2 type arrangement of rays in the lateral lobe of the bursa; rays 5 and 6 longer than rays 2 and 3; dorsal ray with one pair of short branches from the main trunk, each of which divided again; genital cone with a pair of dorsal raylets which were separate along their length; unique ornamented spicules 584 (24-5) Mm long (Fig 1). The synlophe, studied in tranverse sections of the mid-body region in five specimens, was consistent with the description in Beveridge and Durette-Desset (1994), in that it was frontal type, with the fluid layer absent and the presence of 26 small ridges oriented perpendicular to the body. C mentulatus was not found in any of the other 222 roe deer collected from the same alpine valley between 1992 and 1997 (Rossi and others 1997). To the authors' knowledge, this is the first record ofC mentulatus in a roe deer and more generally in a free-ranging cervid host. Animals belonging to a small circus which visited Oulx during the summer of 1996 were the most likely source of infection. Local people reported that an unspecified number of llamas and a camel were allowed to graze the meadows around the circus camp, just a few hundred metres from where the infected roe deer was subsequently recovered. Following the movement of infected animals, C mentulatus has become endemic in sheep and goats in arid zones in Australia and the Canary Islands (Beveridge and Ford 1982, Molina and others 1997) and is now signalled in other ruminant hosts in zoos and exotic game farms in temperate zones of the northern Hemisphere (Thornton and others 1973, Hernandez and others 1980). At the beginning of the last FIG 1: Distal tip of typically ornamented spicules of Camelostrongylus mentulatus from a roe deer. Bar = 50 ipm