Comparison of the FLOTAC technique with the McMaster method and the Baermann technique to determine counts of Dictyocaulus eckerti L1 and strongylid eggs in faeces of red deer (Cervus elaphus)

Abstract

The FLOTAC flotation technique has been introduced as a new diagnostic tool to detect parasitic elements from faeces. Samples from naturally infected young deer were used for counting Dictyocaulus larvae and strongylid eggs. The FLOTAC technique, using 11 different flotation solutions with specific gravities (sg) between 1.20 and 1.45, was compared with the Baermann technique and the saturated sodium chloride (sg 1.20)-based McMaster method. In addition, a comparison was made between the FLOTAC technique with magnesium sulphate (sg 1.28) and the Baermann technique for larval recovery from faeces that were examined on the day of collection or after 7 days storage at 4 degrees C. On the whole egg counts between the FLOTAC using different flotation solutions and the McMaster were unremarkable. In contrast, variations of larval counts were detected between different flotation solutions as well as with the Baermann technique. Most flotation solutions with a specific gravity of 1.20 floated significantly fewer lungworm larvae (p < 0.05) compared to flotation solutions with a higher specific gravity. Magnesium sulphate (sg 1.28) consistently produced the highest mean larval counts in all conducted experiments. Larval counts using magnesium sulphate (sg 1.28) were higher than with the Baermann technique both on the day of collection and after 7 days. Overall, the use of magnesium sulphate (sg 1.28) with FLOTAC for larval counts resulted in higher counts than the Baermann recovery technique and was the better choice of those flotation solutions examined. Furthermore, magnesium sulphate (sg 1.28) was also reliable for strongylid egg detection with the FLOTAC apparatus.