Survey of ticks of domestic dogs and cattle in three Caribbean islands.

Ticks and the pathogens they transmit can cause high morbidity and mortality in domestic animals. As part of a larger study to determine the tick-borne pathogens infesting domestic animals and wildlife, the aim of this study was to survey the tick species infesting the canine and cattle populations in Trinidad, Tobago and St. Lucia. A total of 1,990 ticks were collected off 179 dogs in Trinidad (n = 163) and Tobago (n = 16) between June 2016 and 2018. Ticks were also collected from cattle throughout Trinidad (n = 1,098), Tobago (n = 306) and St. Lucia (n = 176). Collected ticks were morphologically identified using standard taxonomic keys. Tick-infested dogs were characterized as pets (n = 161) or hunting dogs (n = 18). Only two tick species, Rhipicephalus sanguineus (1,926; 96.8%) and Amblyomma ovale (64; 3.2%), were found on the dogs. A total of 169 (94.4%) dogs and 10 (5.6%) dogs were infested with R. sanguineus and A. ovale, respectively. Three dogs (1.7%) were infested with both tick species. Hunting dogs or those closely associated with them were infested with A. ovale. Rhipicephalus sanguineus was widely distributed throughout both islands, whereas A. ovale was restricted to small foci in three rural settlements in both Trinidad (n = 2) and Tobago (n = 1). Rhipicephalus (Boophilus) microplus (n = 1,404) was the only tick species found in cattle from Trinidad (n = 62) and Tobago (n = 20), whilst R. B. microplus (n = 171) and Amblyomma variegatum (n = 5) were found infesting 14 and two heads of cattle, respectively, in St. Lucia. These preliminary findings will aid in determining whether there are links between ticks and tick-borne pathogens associated with domestic, wildlife species and humans and give further insight into the potential movement of ticks and their pathogens between the human, animal and tropical forest interface.