| dc.description.abstract | Certain helminth eggs and oocysts excreted in a dog’s faeces may originate from intestinal passage after coprophagia. As a consequence, the results of faecal examination can be false positive for patent infections. The objective of this study was to investigate to what extent coprophagia interferes with the prevalence of dogs shedding helminth eggs and/or (oo)cysts. As part of a longitudinal study, dog owners with a dog older than 6 months, submitted a faecal sample monthly and filled out a questionnaire. A total of 5711 faecal samples were analyzed during my research period (February 3, 2014 until April 4, 2014) and during the period March 1, 2012 to March 1, 2013. The faecal samples were examined for the presence of intestinal parasites using a Centrifuge Sedimentation Flotation technique with sucrose solution as flotation medium (density: 1,27-1,30 g/cm3). If a sample tested positive for Toxocara spp., T. vulpis, canine hookworms and/or Capillaria spp. at the first examination, the owner was asked to submit a second faecal sample (also referred as confirmation sample) after keeping the dog from eating faeces for three days. In this way, differentiation between passive passage and patent infection was possible.
A remarkable percentage of positive samples returned as negative confirmation samples: 40,9% for Toxocara spp. eggs, 69,6% for strongyle-type eggs and 53,8% for T. vulpis eggs between March 2012 and March 2013. During my research period in 2014, 40% of the confirmation samples for Toxocara spp. eggs and 100% of the confirmation samples for strongyle-type eggs were negative. Contrary to our expectations, no significant association was found between reported coprophagy and the number of negative confirmation samples. The finding of non-dog typical parasites in the faeces of not coprophagic dogs, proved that the owners’ perception of the coprophagic behaviour of their dog is not always reliable. In conclusion, results showed that a considerable percentage of infections with T. canis, T. vulpis and hookworms diagnosed by a single faecal examination can be false positive. In dogs, prevalence estimates for patent helminth infections are usually based on a single faecal examination. Prevalence rates reported in cross-sectional prevalence studies may thus be overestimated and require cautious interpretation. Repeated faecal examinations are recommended to confirm patent infections. Further studies with a higher compliance of owners providing confirmation samples are necessary for a reliable determination of the exact influence of coprophagia on the prevalence of household dogs shedding helminth eggs and (oo)cysts. | |
