What is the most common method used to examine a fecal sample?

The most common method used to examine a fecal sample is flotation. This technique is particularly effective for identifying the presence of parasitic eggs and cysts within the fecal material. During flotation, the sample is mixed with a solution that has a higher specific gravity than the eggs. As the sample is processed, the parasitic eggs float to the surface due to their lower density, allowing for easier collection and examination under a microscope. This method is widely utilized in veterinary practices because it is efficient and provides a clearer view of the eggs compared to other methods, making it highly valuable for diagnosing parasitic infections in animals.

While direct smear, quantitative tests, and centrifugation are also valid methods for examining fecal samples, they serve different purposes or are less commonly employed for the main goal of identifying parasites. Direct smear can be useful for a quick examination but often does not yield as clean a result as flotation. Quantitative tests are typically used to measure the concentration of eggs in a sample, which is less common for routine examinations. Centrifugation can improve the recovery of eggs or cysts by separating them from fecal debris, but it is often more complex and time-consuming than flotation for standard evaluations.