TDK conference 2019

Most wild animals are infected with a wide variety of parasites, including parasites of zoonotic importance. In Europe, Echinococcus multilocularis tapeworm, considered to be the most dangerous parasite for humans. The definitive host of this worm on the continent is the red fox. Currently, the number of foxes is increasing due to the eradication of rabies. In consequence of the enlarging populations more and more foxes visit human settlements. Therefore the examination of parasites living in foxes is important to avoid contamination of humans, pets and livestock. However, the examination of helminths in foxes is not as easy as those of animals living in the human environment or that wild game which used for human consumption. The dissection of carcasses of shot foxes is only possible in laboratories that are suitable for this purpose. It seems easier to carry out parasitological examination of their excrements collected on the ground, but it is questionable to what extent the parasites contained there in reflects the actual infection of the animals?

In our work, we examined 198 red fox droppings by flotation between 2016 and 2019. Most of the samples came from the Bükk Mountains, and we also analyzed faeces collected from Pilis Mountains, Buda Hills, Gemenc forests, swamps near Ócsa and pastures in Szabolcs-Szatmár-Bereg County. We supplemented our observations with the necropsy and coprological examination of 27 foxes which were shot near Szeged and Sopron.

The eggs of the Capillaria species were detected in most samples and the incidence of eggs of Alaria alata trematode, eggs of Toxocara canis and Toxascaris leonina roundworms, and eggs of Ancylostoma caninum, Uncinaria stenocephala hookworms were also significant. Several less common parasites were found in faecal samples, and in many cases we found parasites of consumed prey. Taenia-type of eggs, which might endanger humans, were detected in very few cases, only in 8% of the droppings. By the flotation method we were also able to detect larvae of Angiostrongylus and Crenosoma lungworms, although this test method is not the most commonly used method for detecting worm larvae. However, in the dissected foxes, in addition to the above parasites, we also found Mesocestoides tapeworms, which could never be detected by faecal examination. Echinococcus worms could not be detected in any foxes.

The results show that most intestinal parasites of foxes can be detected by the simple flotation method, but the autopsy allows the detection of even more parasites. Given the possibilities, both methods are suitable for parasitological monitoring.