Ticks are obligated ectoparasites of mammals, reptiles, and birds. These are vectors of diseases affecting domestic, wild animals and humans. The aim of this study is to identify ticks that are naturally infesting dogs in Juarez and Nuevo Casas Grandes in Mexico. The only inclusion criteria were that the dogs presented with ticks. The dog variables to be measured were age, sex, and signs of disease. Ticks are preserved in 70% alcohol, and their identification was performed at the Laboratory of Clinical Pathology of the Autonomous University of Juarez and in the Parasitology Laboratory of the National Service of Agroalimentary Sanitation, Innocuity and Quality of Mexico. In this laboratory, they have a manual for taxonomic identification of ticks. A record of each tick was performed, and the following variables were registered: species, life stage, and sex.

Obtained were 1689 ticks from a total of 424 dogs. Identified as Rhipicephalus sanguineus were 1686 ticks (99.83%), and three (0.17%) were Otobius megnini.

Results of this investigation are similar to those described by several authors worldwide. Cosmopolitan distribution of R. sanguineus comes from its ability to survive in extreme conditions of heat and low environmental humidity. It is important to emphasize that R. sanguineus is a vector of pathogenic microorganisms (Ehrlichia canis, Rickettsia rickettsi and Babesia canis) affecting dogs and humans. This point, in addition to the high presence of R. sanguineus in dogs from these two cities, should alert the scientific community and government to implement effective methods to control this ectoparasite.