Monthly fluctuation of parasitism by adult Ixodes keiransi ticks in dogs from Yucatán, Mexico

The monthly fluctuation of adult Ixodes keiransi in dogs from two cattle farms in southeastern Mexico was determined. In ranch 1 (R1), 6–7 mixed breed dogs from six months to five years of age; while in ranch 2 (R2), 7–8 mixed breed dogs from one to four years of age, were followed. All dogs were monthly inspected for tick infestation through one year. The abundance of dogs infested with ticks was estimated for each month. Tick specimens were taxonomically identified as I. keiransi using morphological features. In R1 the dogs were inspected 60 times and in R2 90 times. The overall proportion of dogs infested by ticks through the year was 75% (60/80) in R1 and 67% (67/90) in R2. The higher abundance of adult I. keiransi parasitizing dogs was from July to December with maximum peaks from September to November. In April, May and June, no ticks were observed on dogs from both ranches. Tick abundance fluctuation showed a concordant pattern with rainfall but with a delay because de maximum peak of I. keiransi abundance was almost two months after the greatest rainfall peak. It is concluded that, in some conditions, the adult I. keiransi in southeastern Mexico presents high-infested rates on dogs and a maximum abundance from September to November. The I. keiransi abundance fluctuation showed a concordant pattern with rainfall.