High seroprevalence, clinical predictors, and epidemiological risk factors of Ehrlichia canis infection in dogs on the Northern Coast of Perú: A large-scale cross-sectional study

Vet World Vol.18 December-2025 Article - 22

Research Article

Veterinary World, 18(12): 3968-3981

https://doi.org/10.14202/vetworld.2025.3968-3981

Raquel Patricia Ramírez-Reyes¹

, Liany Karina Quispe-Rodríguez¹

, Roy Macedo-Macedo¹

, and Juan R. Paredes-Valderrama²

1. Research Hotbed in Companion Animals, Faculty of Agricultural Sciences, Veterinary Medicine and Zootechnics study program, Universidad Privada Antenor Orrego (UPAO), Trujillo, Perú.

2. Animal Science Research Unit, Faculty of Agricultural Sciences, Veterinary Medicine and Zootechnics study program, Universidad Privada Antenor Orrego (UPAO), Trujillo, Perú.

Background and Aim: Canine monocytic ehrlichiosis, caused by Ehrlichia canis and transmitted primarily by Rhipicephalus sanguineus, is a common yet diagnostically challenging tick-borne disease in tropical regions. On the northern coast of Perú, environmental conditions favor vector persistence, but local data on clinical characteristics and risk determinants remain limited. This study aimed to determine the seroprevalence of E. canis in domestic dogs in Trujillo (La Libertad, Perú), describe associated clinical findings, and identify epidemiological risk factors linked to infection.

Materials and Methods: A cross-sectional analytical study was conducted from December 2023 to August 2024 involving 462 dogs with compatible clinical signs and/or tick infestation from 18 veterinary clinics across three districts. Serological testing was performed with the CaniV-4® rapid test, and hematological parameters were analyzed with an automated analyzer. Epidemiological data were obtained through owner questionnaires. Associations were evaluated using chi-square tests, logistic regression (Odds ratio [OR], 95% CI), and Mann–Whitney U tests for hematological differences. A p-value < 0.05 with OR and lower CI >1 defined risk factors.

Results: The overall seroprevalence of E. canis was 51.3% (95% CI: 46.7%–55.8%). Sex and breed were not associated with infection. Dogs <1 year old (OR = 1.46), those lacking external deworming (OR = 1.99), fed homemade diets (OR = 2.26), and those frequently contacting stray dogs (OR = 4.33) were at significantly higher risk. Clinical predictors strongly associated with infection included lethargy (OR = 5.55), fever (OR = 5.52), anorexia (OR = 4.24), anemia (OR = 4.12), lymphadenopathy (OR = 3.46), and epistaxis (OR = 2.50). Seropositive dogs exhibited significantly reduced erythrocyte counts, hematocrit, hemoglobin, leukocyte counts, and platelet counts (p < 0.01). Although tick presence and park access were associated with seropositivity, their OR < 1 suggested confounding rather than true protective effects.

Conclusion: The high seroprevalence and significant clinical–hematological alterations highlight widespread exposure to E. canis among dogs in northern coastal Perú. Identified risk factors emphasize the need for integrated tick-control, improved owner awareness, and strengthened diagnostic protocols. Future research combining molecular confirmation, socioeconomic variables, and One Health–based surveillance is recommended to refine prevention and management strategies.

Keywords: canine ehrlichiosis, clinical signs, Ehrlichia canis, hematological alterations, Perú, Rhipicephalus sanguineus, risk factors, seroprevalence, stray dogs, tick-borne disease.

How to cite this article: Ramírez-Reyes RR, Quispe-Rodríguez LK, Macedo-Macedo R, and Paredes-Valderrama JR (2025) High seroprevalence, clinical predictors, and epidemiological risk factors of Ehrlichia canis infection in dogs on the Northern Coast of Perú: A large-scale cross-sectional study, Veterinary World, 18(12): 3968–3981.

Received: 22-06-2025 Accepted: 21-11-2025 Published online: 18-12-2025

Corresponding author: Juan R. Paredes-Valderrama E-mail: jparedesv7@upao.edu.pe

DOI: 10.14202/vetworld.2025.3968-3981

Copyright: Ramírez-Reyes, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.