Epizootic features of opisthorchiasis in domestic cats in the east of West Siberia

Abstract

The Tomsk Region is one of the leaders in Russia in terms of opisthorchiasis incidence in humans and animals. This is due to the fact that the City of Tomsk is located on the Tom River where there is a natural reservoir of this type of helminth. Feeding infected river fish to carnivores contributes to the fact that the causative agent of opisthorchiasis constantly circulates in nature. The research goal was to study the spread of opisthorchiasis in domestic cats in the City of Tomsk taking into account the seasonal and age dynamics. The studies were conducted from 2021 through 2023 at private veterinary clinics ZooClinic and Center for Veterinary Medicine of Dr. Nidzelskiy in the City of Tomsk. For the period from 2021 through 2023, altogether 502 cats were examined of which 104 cats were infected with opisthorchiasis. The average extensiveness of invasion over 3 years was 21.38%. The highest extensiveness of invasion was observed in 2021 - 24.43%; in subsequent years a decrease of infestation was observed to 22.44% in 2022 and 17.28% in 2023. The age of animals infected with opisthorchiasis varies from 1 year to 11 years. Most often, cats of the age from 3 to 6 years suffer from opisthorchiasis, less often the disease is recorded in old animals older than 8 years. Infection of animals with opisthorchiasis occurs in all seasons of the year. The seasonal patterns of the disease do not actually differ from year to year, the largest number of sick animals is recorded in the summer-autumn period from April to September; perhaps this is due to the fact that at this time fishing and feeding fish to domestic carnivores is more active. Analyzing the data obtained, it may be noted that the number of cats infected with opisthorchiasis has been slowly decreasing in recent years.