Dr. Murai Éva - Gubányi András szerk.: Parasitologia Hungarica 27. (Budapest, 1994)

magna will certainly not cause a pathological condition of fatal outcome in Hungarian deer either, by impairing the animals' natural resistance it may lead to a loss of condition and a consequent deterioration of the trophy in value. Under the present conditions no effective measures can be taken to control the spread of the large American liver fluke. Theoretically, drug therapy could be used; however, for entirely free-moving game this approach is unfeasible. In other countries the following two different treatment approaches are recommended for the control of fluke infestation in cervids. The approach considered to be more effective requires immobilization of the animals with an immobilizing bullet and intraruminal drenching of a suitable anthelmintic, followed by a 30-day quarantine period (!) until complete excretion of helminth eggs. Although such administration of an anthelmintic is rather expensive and involves a risk to the animals, it gives almost 100% efficacy if triclabendazole, a compound known to have excellent activity against F magna (Pybus et al. 1991), is used. Despite its efficacy, this method is an unlikely candidate for use in areas other than game preserves with a game population kept in an enclosed area, as a very high proportion of deer living in a given area would have to be captured for a successful control of infection. This would involve enormous costs, rendering this approach of fluke control uneconomical. Free-ranging trophied game showing only spontaneous territoriality can only be medicated with anthelmintics mixed in bait or feed. This method will be effective only if there is no abundance of feed in the given area, or if the animals regularly visit the feeders for some other reason, thus taking up the required dose of drug with high reliability. The efficiency of medication with anthelmintic-containing bait is far lower than that of individual treatment; hence, the 63% reduction achieved by such medication in F magna infection of white-tailed deer can be considered a fairly good result (Qureshi et al. 1994). This form of medication requires the use of an anthelmintic of very low toxicity, as the feed intake of individual game specimens living in herds is not equal because of the hierarchy existing within the herd. With such medication it is an important requirement that animals occupying a higher rank in the hierarchy should not take up toxic amounts of drug even with the higher amount of feed consumed; at the same time, animals having lower ranks in the hierarchy should also have access to an effective dose of drug with the feed left over by the others. This principle can only be met in a satisfactory manner by administering an anthelmintic at a low dose for a long time. Apart from the technical difficulties, prolonged medication also poses the problem of drug residues accumulating in the meat. Theoretically, domestic animals can be treated with different fasciolicides without any difficulty also in the case of F magna infection. However, it must be kept in view that for destruction of the flukes living in a thick connective tissue capsule the common fasciolicides must be used at multiples of their normal dose. That dose is often close to the toxic level even in the case of individual treatment, not to speak of the potential adverse consequences of group medication used for free-ranging deer. Triclabendazole was used for treating^ magna infection in white-tailed deer at a dose