Coprological methods for the diagnosis of Anoplocephala perfoliata infection of the horse

Objective To compare the sensitivities of three coprological techniques for the diagnosis of Anoplocephala perfoliata infection in horses and to assess the value of the methods for diagnosis of horses at risk of clinical cestodiasis. Design Faecal samples were collected from necropsied horses with or without A perfoliata infection and examined using one sedimentation and two different flotation methods. The coprological results were compared with worm counts performed at necropsy of the horses and the degree of mucosal damage. In addition, the efficiency of recovery of A perfoliata eggs from faeces was tested. Results The overall sensitivities of the methods ranged from 22.5 to 37.5%, and the capacity of the methods to diagnose infection increased with the intensity of infection. A simple flotation method achieved a better sensitivity (37.5%) at all intensities of infection compared with the other two methods (22.5 to 25%). That method was also more sensitive in detecting eggs in ‘negative’ faecal samples spiked with known numbers of A perfoliata eggs. Conclusion The results indicated that, despite the low sensitivities of present methods, faecal flotation is likely to be of value in detecting horses at risk of clinical disease.