Correlation between the fecundity of T. canis, the worm burden and sex distribution in Dutch red foxes (Vulpes vulpes) with a comparison of McMaster and mini-FLOTAC.

Abstract

Background: Toxocara canis prevails to be a prevalent zoonotic agent in the environment. The natural sources of its eggs, such as the red fox (Vulpes vulpes), have to be more deeply investigated.There is still a lack of understanding of their role in the zoonotic transmission of infective stages of T. canis in relation to the public health. We do have a much deeper understanding of the role of household dogs (Canis lupus familiaris) on the contamination of the environment with infective stages of T. canis than we do on foxes. Objective: In this paper the main focus lies on possible relations between the age, gender, and body condition score (BCS) of the host with the intestinal worm count, the gender of the worms, the fecundity of female worms as well as the eggs per gram faeces (EPG). Method: The data used in this study has been derived from dissections of foxes, qualitative as well as quantitative coproscopical examinations and counting as well as sexing of the worms. The quantitative EPG counts were done with two different techniques, the proven McMaster and the new mini-FLOTAC method. Results: Only the BCS correlated positively with the intestinal worm count. Neither the age nor the gender of the foxes could be associated with the EPG count or the intestinal worm count. The compared quantitative techniques had a high concordance and verified earlier results from the literature. Conclusion: The mini-FLOTAC technique has proven to be a viable but more time intensive alternative to the McMaster technique, with a higher resolution and a lower detection threshold.