Fecal floatation and KeyScreen polymerase chain reaction optimize Echinococcus multilocularis detection in canine feces for veterinary practice and zoonotic surveillance.

The objective of this study was to compare 4 different fecal diagnostic methods for detection and recovery of Echinococcus multilocularis eggs. Four methods were compared: passive fecal float, centrifugal fecal float, mini-FLOTAC, and the KeyScreen GI PCR Parasite panel (Antech Diagnostics). Domestic dog feces were spiked with 8 egg concentrations (0, 10, 25, 50, 60, 100, 200, and 500 eggs/g). Each concentration had 10 replicates. Detection frequency (ability to detect ≥ 1 egg) and mean egg recovery were assessed. The centrifugal method had the lowest detection limit, detecting eggs at 10 eggs/g in 20% of replicates, though mean recovery was low. The mini-FLOTAC demonstrated the highest mean egg recovery and overall accuracy (9.01%) among quantitative methods. Passive float and KeyScreen detected eggs consistently at ≥ 60 eggs/g, with KeyScreen showing higher detection frequency than passive floats. Importantly, KeyScreen is the only method that can distinguish Echinococcus species from the more common Taenia species. The mini-FLOTAC is practical for veterinary offices, particularly where centrifugation is unavailable, offering efficient Echinococcus egg recovery. KeyScreen provides species-level confirmation while detecting low-concentration infections. This is particularly important in areas where Echinococcus species are emerging and zoonotic risk is a concern. Accurate diagnostic methods are essential for veterinary practice and One Health surveillance, and all dogs should be regularly tested and treated. The companion Currents in One Health by Garrett et al, JAVMA, November 2026, addresses the natural history of the 2 most common Echinococcus species of concern in North America, E multilocularis and Echinococcus canadensis (G8 and G10).