Rhipicephalus sanguineus on dogs: relationships between attachment sites and tick developmental stages

The brown dog tick, Rhipicephalus sanguineus, is the most widespread tick in the world and infests primarily domestic dogs. Studies on the bio-ecology of R. sanguineus have been carried out worldwide, but little is known of the on-dog relationships of tick developmental stages and their possible role on tick feeding performance, reproduction and pathogen transmission. We studied the relationships between different developmental stages of R. sanguineus on particular body areas of naturally infested dogs. In addition, we assessed whether these relationships could vary according to sex and breed of the dogs. Over 2,200 tick records were analyzed and the results showed that attachment sites of males and females are strongly positively correlated whereas attachment sites of nymphs and adults tend to be negatively correlated. Our findings indicate that adult ticks generally feed on sites (e.g., ears) that make it difficult for dogs to remove them, whereas immatures feed on lower areas of the dog's body (e.g., belly, rump, and hind legs), probably because of their more limited mobility. Further research on the possible on-dog interactions of adult and immature ticks is needed to better understand why their attachment sites tend to be negatively correlated and to assess their possible implications for pathogen transmission.