Abstract
Background
Tick infestations and canine tick-borne diseases have become a major emerging health concern of dogs in Sri Lanka. Information about tick species infesting dogs and their geographic distribution in Sri Lanka is largely unknown.
Methods
An island-wide, cross-sectional survey of tick species infesting the domestic dog was carried out, and the life cycle of the major dog tick, Rhipicephalus sanguineus was studied under laboratory conditions.
Results
A total of 3,026 ticks were collected from 1,219 dogs of different breeds in all 25 districts in the three climatic zones: Wet, Dry, and Intermediate zones. Eight species in five genera were identified: R. sanguineus (63.4%), Rhipicephalus haemaphysaloides (22.0%), Haemaphysalis bispinosa (12.5%), Haemaphysalis intermedia (0.9%), Haemaphysalis turturis (0.6%), Amblyoma integrum (0.4%), Dermacentor auratus (0.2%) and Hyalomma sp (0.06%). The brown dog tick, R. sanguineus was the dominant species in the Dry and Wet zones, while R. haemaphysaloides was the dominant species in the Intermediate zone. Species diversity (presented as Shannon diversity index H) in the three was 1.135, 1.021and 0.849 in Intermediate, Dry and Wet zones, respectively. Adults formed 94.7% with a significantly higher number of females, and the rest were nymphs. Rhipicephalus sanguineus preferred the anterior side of the host body, specifically the inner and outer side of the ear. In contrast, R. haemaphysaloides preferred the posterior side, mainly the fore and hind limbs. The three-host life cycle of R. sanguineus was completed within 70–126 days, all three stages successfully fed on the New Zealand white rabbits under laboratory conditions. The mean REI and RFI were 50.8 ± 9.69 and 9.1 ± 5.01, respectively. Larger females had higher reproductive success.
Conclusion
The dominant dog tick species and the species diversity varied in different climatic regions of Sri Lanka. Information on diversity, distribution and life cycle parameters is fundamental for studies of canine tick-borne infections, zoonoses, and their epidemiology.
Distribution and population dynamics of ticks (Acari : Ixodidae) infesting sheep in Sennar State, Sudan