Calicophoron daubneyi (Paramphistomidae) in deer of the Sumava National Park, Czech Republic - Consequence of prevalent rumen fluke infection in cattle.

A substantial parallel increase in prevalence and geographical spread of the rumen fluke, Calicophoron daubneyi, in livestock in western and central Europe has been recognized in the recent past. In the course of the examination of rectum feces of 471 red deer (Cervus elaphus) and one sika deer (Cervus nippon) from the Fascioloides magna endemic Sumava National Park in the years 2021 and 2022, rumen fluke eggs were detected in four red deer (0.8%) and the sika deer and identified as eggs of C. daubneyi by molecular analysis. Subsequent examination of rectal fecal samples of 247 beef cattle from 22 herds of 14 farms located in or nearby the national park revealed rumen fluke eggs in 53 samples (21.5%) originating from 16 herds of 11 farms, molecularly identified as C. daubneyi eggs as well. One C. daubneyi egg positive red deer and three C. daubneyi egg positive cattle samples also contained fasciolid eggs, respectively, which were detected in 9.5% or 3.6% of the total samples from red deer or cattle, respectively. Results of this investigation reveal the first finding of C. daubneyi in sika deer worldwide and in red deer in mainland Europe and add to the growing number of reports on C. daubneyi in livestock in Europe. Considering that the ratio of cattle excreting rumen fluke eggs exceeded that of deer substantially, it can reasonably be assumed that the C. daubneyi infections in deer are a consequence of the prevalent infection in cattle, illustrating a pathogen spillover event from livestock into wildlife.

Multispecies helminth parasitism of grazing dairy cows in Germany and Austria, examined in the housing period.

Helminth composition and burden data for dairy cows have not been reported for >40 years for Germany and even less information is available for Austria. In the context of two recent studies, helminth parasitism was studied in 32 cows (23 from six farms in Bavaria and Tyrol; 9 from one farm in Saxony) from pasture-based dairy farms necropsied during the housing period. Helminths were enumerated and identified based on morphological characters (all helminths but rumen flukes) or molecular techniques (rumen flukes). Thirteen species of gastrointestinal nematodes and two species each of liver flukes (Fasciola hepatica, Dicrocoelium dendriticum) and rumen flukes (Calicophoron daubneyi, Paramphistomum leydeni) were recorded; no lungworms were recovered from any cow. Early fourth-stage (inhibited) larval Ostertagia species nematodes (210 to 140,600) were recovered from all cows, 31 each had adult Ostertagia ostertagi/Ostertagia lyrata (40 to 2020) and Trichostrongylus axei (10 to 53,400), 23 Oesophagostomum radiatum (1 to 242) and 20 Cooperia punctata (10 to 3330). Other nematodes present in descending order of prevalence were: Cooperia oncophora/Cooperia surnabada, Ostertagia leptospicularis/Ostertagia kolchida, Oesophagostomum venulosum, Bunostomum phlebotomum, Chabertia ovina, Nematodirus helvetianus, Trichostrongylus longispicularis, Haemonchus contortus and Aonchotheca bilobata. The cows from Bavaria and Tyrol harbored more total gastrointestinal nematodes than that from Saxony (geometric mean adult plus inhibited larval nematodes, 6510 vs. 2051, respectively). However, in both cohorts of cows abomasal nematodes accounted for ∼97% of the total nematode burden with inhibited larval Ostertagia species nematodes contributing over 70% of the total gastrointestinal nematode burden and âˆ¼ 96% of the Ostertagia species burden. Approximately 44%, 37% and 19% of the cows harbored <5000, 5000 to 10,000 or > 10,000 total gastrointestinal nematodes, respectively. Fecal nematode egg and coproculture nematode larval counts significantly correlated with the cows' total adult nematode burden (rs = 0.354, p < 0.05, and rs = 0.608, p < 0.001, respectively). Although the magnitude of nematode burden to exert production effects on dairy cows is not well defined and may vary relative to several factors including nutritional supplementation, the level of mixed parasitism found in this investigation supports consideration of grazing dairy cows in helminth control measures, especially at the time of housing in autumn.