Prevalence of Alaria infection in companion animals in north central Oklahoma from 2006 through 2015 and detection in wildlife

Abstract

OBJECTIVE To determine the prevalence of Alaria infection in cats and dogs in north central Oklahoma over various periods and investigate whether wild animal species in this region were also infected. DESIGN Combined cross-sectional study and case series. SAMPLE Results of parasitological testing of fecal samples from 5,417 client-owned dogs and 1,246 client-owned cats (2006 through 2014); fecal samples from 837 shelter or rescue dogs and 331 shelter or rescue cats (2013 and 2014) and 268 feral cats (2015); tongue or jowl samples from cadavers of 43 wild pigs, 3 opossums, and 1 raccoon; and intestinal tract segments from cadavers of 48 cats and 5 coyotes. PROCEDURES Various parasite recovery techniques were performed to detect various Alaria stages in samples. Recovered adult trematodes and mesocercariae were used for PCR assay and sequencing of the 28S rRNA gene. RESULTS Prevalence of Alaria infection was significantly higher in feral cats (9.0%) than in shelter or rescue cats (0.6%) and client-owned cats (1.4%) and in shelter or rescue dogs (1.8%) than in client-owned dogs (0.2%). Mesocercariae were recovered from tissue samples from 11 (26%) wild pigs and 1 opossum. Amplicon sequences from adult trematodes and mesocercariae were 100% identical to each other and 99% homologous to GenBank sequences of Alaria alata and Alaria mustelae. CONCLUSIONS AND CLINICAL RELEVANCE Prevalence of Alaria infection in the study area has increased in dogs and cats since 1990, when infections were rare. Prevalence in wild pigs was similar to that in Eurasia, where A alata is considered an emerging zoonotic parasite.

Alaria alata (Digenea: Diplostomidae) from Korean Raccoon Dog, Nyctereutes procyonoides koreensis, in Korea

“…Their life cycle requires 2 intermediate hosts. The first intermediate host is a freshwater snail such as Helistoma, Planorbis, Lymnea, and Anisus spp., and the second is an amphibian such as a frog [2]. In addition, many species of omnivorous and carnivorous mammals can also act as paratenic hosts [3,4].…”