Myxobolus cerebralis in Tubifex tubifex from a whirling disease epizootic in Montana.

Aquatic oligochaetes from a whirling disease enzootic area in southwest Montana were examined for infection with Myxobolus cerebralis. Anterior portions of oligochaetes were preserved for specific identification, whereas DNA was purified from posterior portions. The purified DNA was used in a nested polymerase chain reaction (PCR) assay specific for M.

Fascioloidiasis in game-ranched elk from Montana.

The distribution of Fascioloides magna in game-ranched elk and the potential for spread of the parasite through movement of infected animals was examined in Montana (USA). Fecal samples (n = 448) collected from captive elk on 29 game ranches were examined for eggs of F. magna by fecal sedimentation.

Seasonal transmission of Fasciola hepatica in Montana, USA, with detection of infected intermediate hosts using a DNA-based assay.

A cashmere goat ranch in the Beaverhead Valley, southwest Montana, USA reported acute fasciolosis in March 1992. The ranch was used as a study site to gather seasonal transmission data for the liver fluke, Fasciola hepatica. Testing of snails for infection with a nucleic acid-based assay, and use of tracer sheep at the site has shown the seasonal transmission of the parasite is only in late autumn.

Distribution of potential intermediate hosts for Fasciola hepatica and Fascioloides magna in Montana, USA.

A collection of lymnaeid snails in Montana was made over a 3 year period, in conjunction with a state-wide survey of the distribution of liver flukes in Montana. Collection areas were selected based on reports of infected cattle, sheep or wildlife, and with the intent of covering all geographic regions of the state. Snails were found at all 97 of the locations chosen for collections, with lymnaeids collected at 71 of the locations.

Efficacy of ivermectin pour-on against Ostertagia ostertagi infection and residues in the American bison, Bison bison.

Sixteen American bison, Bison bison, were artificially infected with 10(5) infective stage larvae of Ostertagia ostertagi on 21 April 1993. At 42 days post-infection eight bison were treated with 0.5% ivermectin pour-on (500 micrograms/kg bodyweight) and eight treated with the carrier only.