title: American Association of Veterinary Parasitologists' review of veterinary fecal flotation methods and factors influencing their accuracy and use--is there really one best technique?
abstract: The principle of fecal flotation is based on the ability of a solution to allow less dense material (including parasite elements) to rise to the top. However, there are numerous factors that will influence the accuracy and use of such a theoretically simple technique. Whether or not centrifugation is used appears to have an impact on the ability to detect some parasites, but not others. Using a flotation solution with a relatively high specific gravity favors the simultaneous flotation of the diagnostic stages of many different parasites while, at the same time, making recognition of some more difficult because of distortion as well as the amount of debris in the preparation. Dilution methods tend to be less accurate because they require extrapolation; however, they are quicker to perform, in part, because of the cleaner preparation. Timing is a critical factor in the success of all flotation methods, as is technical ability of the personnel involved. Thus, simplicity, low costs and time savings have generally favored gravitational flotation techniques (including the McMaster technique and its modifications). How accurate the method needs to be is dependent upon the purpose of its use and choice of method requires an understanding of analytical sensitivity and expected levels of egg excretion. In some instances where the difference between, for example, 0 and 50 eggs per gram is insignificant with regards to management decisions, less accurate methods will suffice. In others, where the presence of a parasite means treatment of the animal regardless of the numbers of eggs present, methods with higher analytical sensitivities will be required, particularly for those parasites that pass few eggs. For other uses, such as the Fecal Egg Count Reduction Test, accuracy may become critical. Therefore, even though recommendations for standardized fecal flotation procedures have been promoted in the past, it is clear that the factors are too numerous to allow for the recommendation of one, or even a few, procedures for all purposes.
authors.affiliation: Colorado State University, College of Veterinary Medicine and Biomedical Sciences, 1644 Campus Delivery, Fort Collins, CO 80523, USA. Electronic address: lora.ballweber@colostate.edu.
authors.forename: L R
authors.initials: LR
authors.lastname: Ballweber
authors.affiliation: Merial, 26 Av Tony Garnier, Lyon 69007, France.
authors.forename: F
authors.initials: F
authors.lastname: Beugnet
authors.affiliation: Zoetis, 333 Portage St., Kalamazoo, MI 49007, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Marchiondo
authors.affiliation: Kansas State University, College of Veterinary Medicine, 3005 Payne Dr., Manhattan, KS 66503, USA.
authors.forename: P A
authors.initials: PA
authors.lastname: Payne
mesh_terms: D000818:Animals; D005243:Feces / Q000469:parasitology*; D010270:Parasite Egg Count / Q000592:standards / Q000662:veterinary*; D010273:Parasitic Diseases, Animal / Q000175:diagnosis*; D010274:Parasitology / Q000379:methods*; D012680:Sensitivity and Specificity; D012952:Societies; D014730:Veterinary Medicine / Q000379:methods*
keywords: Coproscopy; Fecal egg count; Flotation techniques; Methods comparison; Variability