Evaluation of a double centrifugation technique for the detection of Anoplocephala eggs in horse faeces.
Faecal samples of 250 horses from farms with a known history of tapeworm infection were examined comparatively for cestode eggs using a double centrifugation/combined sedimentation-floatation technique. From each faecal sample, three 5 g and three 15 g subsamples were processed, each using either saturated NaCl solution, specific gravity (sp. g.) 1.2 [NaCl]; concentrated sugar solution, sp. g. 1.26 [sugar]; or concentrated ZnSO4 solution, sp. g. 1.3 [ZnSO4] for floatation. In total, faeces from 187 horses ( = 74.8%) tested 'positive' for Anoplocephala eggs. Percentages of samples testing 'positive' for Anoplocephala ova were: 57.2% for 5 g faeces/NaCl, 66% for 15 g faeces/NaCl, 66% for 5 g faeces/sugar, 72.8% for 15 g faeces/sugar, 55.6% for 5 g faeces/ZnSO4, and 61.2% for 15 g faeces/ZnSO4, respectively. Processing of 15 g faecal samples resulted in a significant (P < 0.05; McNemar's χ2-test) increase in the percentage of Anoplocephala egg detection compared to processing of 5 g samples for all floatation solutions. By processing 15 g faecal samples using sugar solution for floatation, 97.3% of all samples that tested 'positive' for Anoplocephala eggs were identified; there was no significant difference between the rate of samples that tested 'positive' using 15 g faeces/sugar (72.8%) and the total rate of samples that tested 'positive' (74.8%). Conversely, percentages of 'positive' samples from other test combinations were significantly (P < 0.0001, McNemar's χ2-test) lower than the total rate of samples testing 'positive'. Processing faecal samples using sugar solution for floatation gave significantly (P < 0.05, Wilcoxon test) higher Anoplocephala egg counts than using NaCl and ZnSO4 solutions, for both 5 g and 15 g faecal samples. The double centrifugation technique using 15 g faecal samples and concentrated sugar solution for floatation appeared to offer an advantage for the detection of Anoplocephala eggs in horse faeces compared to the other test combinations.
Merial GmbH, Kathrinenhof Research Center, Walchenseestr. 8-12, 83101 Rohrdorf, Germany. steffen.rehbein@merial.com
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Rehbein
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Lindner
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Visser
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Winter
D000818:Animals; D002498:Centrifugation / Q000379:methods*; D002589:Cestoda / Q000302:isolation & purification*; D002590:Cestode Infections / Q000469:parasitology* / Q000662:veterinary*; D005243:Feces / Q000469:parasitology*; D006734:Horse Diseases / Q000469:parasitology*; D006736:Horses; D010270:Parasite Egg Count / Q000379:methods / Q000662:veterinary*; D010274:Parasitology / Q000379:methods