Thelazia callipaeda is a spiruroid nematode of dogs, cats and wild carnivores transmitted by zoophilic drosophilid Phortica flies and found in an increasing number of European countries. In cats the disease is diagnosed sporadically. This study presents an epidemiological investigation of feline thelaziosis, performed in southern Ticino, Switzerland, an endemic area for T. callipaeda. Between J...