Flotation solution influence on the quantification of Ascaris suum eggs in pig feces using McMaster technique

Abstract

Parasitic diseases are responsible for economic losses in the pig production industry. It is necessary to monitor the parasite load through stool ova and parasite analysis to avoid losses to the producer. Among analytical tests, the McMaster technique is the most widely used method; however, several variations of this method have been described, and, therefore, there is a need for standardization. The aim of this study was to evaluate the use of different saturated solutions prepared from four different salts (NaCl, MgSO4, NaNO3, ZnSO4), a sugar solution, and Polysorbate Tween 80, to perform the McMaster technique. Pig feces containing Ascaris suum eggs were homogenized in Griffin beakers and divided into 2g aliquots for the exams with different solutions. All solutions evaluated were able to float A. suum eggs. However, eggs per gram of feces (EPG) values using the sodium nitrate solution were higher (p < 0.05) than for the other solutions. Magnesium sulfate and sodium chloride solutions provided intermediate values for EPG. Lower values were obtained with zinc sulfate and sugar solutions. Polysorbate Tween 80 was added to the sodium nitrate solution at a concentration of 0.2%, and this proved to be more efficient (p < 0.05) in flotation of the eggs.

Keywords

• parasitological techniques, sodium nitrate, tween 80.