Dr. Murai Éva - Gubányi András szerk.: Parasitologia Hungarica 29-30. (Budapest, 1997)

gastroenteritis with high morbidity and mortality rates, particularly in young animals, and is mainly confined to Africa, Asia, Australia, Eastern Europe and Russia (Boray 1959, Horak 1962, Boray 1969, Horak 1971, Gupta et al. 1978, Nikitin 1979, Hanna et al. 1988). It has been considered that all cases of amphistomosis are caused by certain species of the parasite. In Australia and New Zealand the species of amphistomes affecting cattle and sheep are Calicophoron calicophorum and Paramphistomum ichikawai (Brotowidjoyu and Copeman 1979). In Asia, according to information available from India and Ceylon, intestinal amphistomosis in cattle, buffalo, sheep and goat has been identified. The flukes most frequently responsible for the disease are Gastrothylax crumenifer, Cotylophoron cotylophorum, Paramphistomum cervi, Fishoederius elongatus and Explanatum explanatum (Boray 1959, Katiyar and Garg 1965, Rolfe and Boray 1987, Hanna et al. 1988, Sey 1989). Brotowidjoyu and Copeman (1979) assessed the prevalence and intensity of immature and mature flukes in cattle at abattoirs in North Queensland, using high, moderate and low intensity categories of > 20, 10-20 and < 10, respectively. The species of amphistomes obtained was Calicophoron calicophorum. In Thailand, the occurrence of amphistome infections has been reported (Chethanon et al. 1985). The objective of this study is to describe the general trend in the prevalence rates of amphistome infections in beef and dairy cattle in Thailand between 1991 and 1995. MATERIALS AND METHODS Identification of amphistome infections by detection of eggs in the faeces In the period from April 1992 to August 1995, faecal samples were obtained from 4,122 dairy cattle and 3,087 beef cattle in 17 (Bankok, Chaing mai, Nonthaburi, Prachin buri, Nakhorn ratchasima, Saraburi, Ratchaburi, Nakhorn nayok, Phetchaburi, Ayuthaya, Suphanburi, Chonburi, Nakhonpathom, Samuttsakhon, Chanthaburi, Srakaeo, Singhburi) and 2 (Singhburi, Chaînât) provinces of Thailand as illustrated in Fig. 1. Faecal examination was performed by the beads technique (Taira 1985) to determine the prevalence rate of amphistome infections and by simple flotation method to detect concurrent infections. Determination of amphistome infections by detection of adult flukes in the rumen A total of 3,000 beef cattle were examined for rumen flukes from June 1991 to November 1995 at local abattoirs from 7 provinces (Sukhothai, Nakhonpathom, Prachuapkhirikhan, Lopburi, Chonburi, Phetchaburi, Rayong) as illustrated in Fig. 1. to determine the prevalence of adult amphistome infections. Fig. 1. Map of Thailand and study areas of amphistome infections in dairy and beef cattle