A comparison of Mini-FLOTAC and McMaster techniques, overdispersion and prevalence of parasites in naturally infected North American bison (Bison bison) in the USA

William L Johnson; Samantha Reynolds; Colton L Adkins; Bradly Wehus-Tow; Jameson Brennan; Catherine B Krus; Danielle Buttke; Jeff M Martin; Jeba R J Jesudoss Chelladurai

doi:10.1016/j.crpvbd.2022.100103

A comparison of Mini-FLOTAC and McMaster techniques, overdispersion and prevalence of parasites in naturally infected North American bison (Bison bison) in the USA

Curr Res Parasitol Vector Borne Dis. 2022 Nov 8:2:100103. doi: 10.1016/j.crpvbd.2022.100103. eCollection 2022.

Authors

William L Johnson¹, Samantha Reynolds¹, Colton L Adkins¹, Bradly Wehus-Tow², Jameson Brennan², Catherine B Krus³, Danielle Buttke⁴, Jeff M Martin⁵, Jeba R J Jesudoss Chelladurai¹

Affiliations

¹ Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, KS, USA.
² Department of Animal Science, South Dakota State University, Rapid City, SD, USA.
³ Department of Clinical Sciences, Colorado State University, Fort Collins, CO, USA.
⁴ National Parks Service, Fort Collins, CO, USA.
⁵ Center of Excellence for Bison Studies, South Dakota State University, Rapid City, SD, USA.

Abstract

Several quantitative diagnostic techniques are available to estimate gastrointestinal parasite counts in the feces of ruminants. Comparing egg and oocyst magnitudes in naturally infected samples has been a recommended approach to rank fecal techniques. In this study, we compared the Mini-FLOTAC (sensitivity of 5 eggs per gram (EPG)/oocysts per gram (OPG)) and different averaged replicates of the modified McMaster techniques (sensitivity of 33.33 EPG/OPG) in 387 fecal samples from 10 herds of naturally infected North American bison in the Central Great Plains region of the USA. Both techniques were performed with fecal slurries homogenized in a fill-FLOTAC device. In the study population, prevalence of strongyle eggs, Eimeria spp. oocysts, Moniezia spp. eggs and Trichuris spp. eggs was 81.4%, 73.9%, 7.5%, and 3.1%, respectively. Counts of strongyle eggs and Eimeria spp. oocysts obtained from 1 to 3 averaged technical replicates of the modified McMaster technique were compared to a single replicate of the Mini-FLOTAC. Correlation between the two techniques increased with an increase in the number of averaged technical replicates of the modified McMaster technique used to calculate EGP/OPG. The correlation for Moniezia spp. EPG when averaged triplicates of the modified McMaster technique were compared to a single replicate of the Mini-FLOTAC count was high; however, the correlation for Trichuris spp. eggs was low. Additionally, we used averaged counts from both techniques to show the overdispersion of parasites in bison herds.

Keywords: Bison; Fecal test; McMaster; Mini-FLOTAC; Overdispersion.