Monitoring of ticks parasitic on domestic animals in Yiwu City in 2021

Objective To determine the prevalence of ticks parasitic on domestic animals in Yiwu City of Zhejiang Province.

Methods We monitored， identified and analyzed ticks parasitic on domestic animals in Yiwu in 2021.

Results A total of 452 domestic animals were monitored， of which 306 were infected with ticks， suggesting a prevalence of 67.70%. A total of 2，603 ticks were captured， and the tick index was determined to be 5.76. The ticks were identified to belong to one family， four genera， and 10 species. Haemaphysalis longicornis was the dominant tick （59.16%），followed by Rhipicephalus haemaphysaloides （26.32%） and Rhipicephalus microplus （6.45%）. Prevalence of ticks， tick index， and number of tick species were listed for domestic animals as follows： goats （74.37%， 7.45， 7 species）， yellow cattle （62.50%， 4.14，6 species）， and dogs （54.62%， 2.59， 8 species）. Moreover， goat was the main domestic animal infected with more than two tick species （25.99%）； H.longicornis （91.26%） was the species with most repated infections. The dominant species of ticks were H.longicornis （65.15%） and R.haemaphysaloides （29.42%） in goats， R.microplus （67.67%） and R.haemaphysaloides （20.69%） in yellow cattle， and H.longicornis （57.14%） and Haemaphysalis porcupines （21.10%） in dogs. However， seasonal fluctuation in tick index differed among goats， yellow cattle and dogs. The fluctuation in tick index in goats and dogs was consistent with that of H.longicornis， with a major peak in March and the minor peaks in September and October. The fluctuation in tick index in yellow cattle was consistent with that of R.microplus， with two peaks in April and August-September. In addition， larval ticks， nymphal ticks and adult ticks were caught in this study， among which nymphal ticks were most common. We found that single domestic animals were infected with ticks of the same species and different stages， which was more common in goats and those animals infected with H.longicornis.

Conclusion Ticks parasitic on domestic animals are common in Yiwu. Multiple species of ticks have been identified， with H.longicornis as the dominant species. It warrants further monitoring and countermeasures.