Spatial and temporal prevalence, abundance and infestation intensity of the ixodid tick population on small domestic ruminants (goat and sheep) in different agro-climatic regions of Tamil Nadu

Abstract

Tick borne diseases are emerging in various agro-climatic regions, affecting both humans and domestic animals such as small ruminants (goats and sheep). The distribution and abundance of tick vectors across agro-climatic regions are influenced by seasonal variations. A comprehensive tick survey was carried out on small ruminants in 220 villages across seven agro-climatic regions during the four seasons of Tamil Nadu. A total of 51,694 ticks were collected, with 36,522 (70.6 %) from goats and 15,712 (30.4 %) from sheep, representing 16 species from four genera. Haemaphysalis intermedia was the most prevalent tick species (89.7 %), while Rhipicephalus microplus was the most abundant (7.8) ticks in small domestic ruminants. Tick species diversity was higher in goats (14 species) compared to sheep (13 species). The highest species diversity in goats was recorded in the hilly agro-climatic regions (10 species) and during the summer season (11 species), while the highest species diversity in sheep was observed in the southern agro-climatic region (10 species) and during the winter season (12 species). H.intermedia was the most prevalent species in both goats (89.4 %) and sheep (97.0 %). The highest abundance was reported Rh.microplus in goats (8.14) and H.intermedia in sheep (7.4). Infestation intensity for H.intermedia was observed highest in both goats (5.6) and sheep (6.0), with an infestation rate of 42.5 % in both species. This study provides the first comprehensive report on tick species diversity in small ruminants in Tamil Nadu, revealing the highest species diversity and documenting several species not previously reported in this region.

Keywords: Haemaphysalis turturis; Hyalomma anatolicum anatolicum; Ixodidae; Rhipicephalus ramachandrai; Tick species infestation; Tick survey.