Emergence ofThelazia callipaedaInfection in Dogs and Cats from East-Central Portugal

Abstract

The eyeworm Thelazia callipaeda (Spirurida, Thelaziidae) infects domestic animals, wildlife and human beings, and is considered an emerging pathogen in Europe. This study aimed at investigating the prevalence and risk factors of T. callipaeda infection in dogs and cats from east-central Portugal, a region where the parasite was previously detected in two red foxes (Vulpes vulpes). Thelazia callipaeda was found in 22 (3.8%) of 586 dogs and in four (23.5%) of 17 cats. A total of 178 adult worms (71.9% of females and 28.1% of males) were collected from the conjunctiva of the infected dogs. The number of worms collected per dog ranged from 1 to 35 (average ± standard deviation: 8.08 ± 9.49), with four dogs (18.2%) harbouring only a single parasite. Worms were gathered from dogs throughout all months of the year. A total of 17 adult worms (64.7% of females and 35.3% of males) were obtained from cats. The number of worms per cat ranged from 1 to 14 (4.3 ± 6.5), with three cats (75.0%) having a single parasite. Eyeworm infection was statistically more prevalent in pastoral and farm dogs, in those dogs with contact with other animals and in dogs with ocular manifestations. T. callipaeda is endemic in the east-central part of Portugal, reportedly infecting domestic (dogs and cats) and wild carnivores (red foxes) and evidencing a southerly dissemination. Future investigations should be focused on determining the local distribution and density of the insect vector (Phortica variegata) in this geographical area. This emergent zoonosis should be included by veterinarians, physicians and ophthalmologists in the differential diagnosis of ocular manifestations in their patients, particularly in areas where T. callipaeda is endemic.

The role of wild canids and felids in spreading parasites to dogs and cats in Europe. Part II: Helminths and arthropods

“…Therefore, the increased number of cases of T. callipaeda infection in Europe reported in the literature may be partly explained by the growing awareness of veterinarians and parasitologists, but may also indicate that canine thelaziosis is emerging in some European areas. Importantly, where the infection in dogs is prevalent, it has also been reported in other host species such as cats (Maia et al, 2014) and foxes (Malacrida et al, 2008;Hodžić et al, 2014;Sargo et al, 2014).…”

Serbia: Another endemic region for canine ocular thelaziosis

“…Climate in the countries where T. callipaeda has been reported varies from tropical (Indonesia) and subtropical (Japan) in the Far East to temperate in the Russian Federation. In Europe, infections by T. callipaeda have been reported in Italy (25), Germany (9), Switzerland (14), France (34), Spain (16), Portugal (13,38), Belgium (5), Serbia (18), and Romania (15).…”

First Report of Thelazia Callipaeda Infection in Amiota Okadai and Wildlife in Wildlife Home Range, China

“…It is generally believed that domestic animals are the most important reservoir host of T. callipaeda and directly threaten humans [11][12][13][14][15][16].…”