Vet World Vol.15 April-2022 Article-39
Research Article
Veterinary World, 15(4): 1121-1128
https://doi.org/10.14202/vetworld.2022.1121-1128
First study on molecular detection of three major canine tick-borne pathogens in subclinically infected dogs in Chiang Mai, Thailand
2. Parasitology Research Laboratory, Institute of Molecular Biosciences, Mahidol University, Salaya, Nakhon Pathom 73170, Thailand.
3. Mission Rabies, Cranborne, Dorset BH21 5PZ, United Kingdom.
4. Merck Animal Health, Madison, New Jersey 07940, United States.
Background and Aim: Canine tick-borne pathogens (CTBPs) are an important cause of morbidity in dogs in Thailand. This study aimed to evaluate the occurrence of three CTBPs in clinically normal, owned dogs to understand the risk for the general canine population. We also examined sex, age, tick infestation, and packed cell volume (PCV) of the animals in association with active infection of the CTBPs.
Materials and Methods: A total of 139 dogs were included in the study. Blood samples were collected for thin blood smear, PCV and nested polymerase chain reaction (PCR) assay. Statistical analyses were performed to examine the association between individual factors and CTBP infection status determined by PCR. In addition, sensitivity, specificity, and Cohen's kappa were calculated to assess the utility of routine blood smear.
Results: The PCR results showed that 31 dogs (22.3%) were infected with at least one of the three pathogens. The occurrence rate for Ehrlichia canis, Anaplasma platys, and Hepatozoon canis was 2.2% (3/139), 18.7% (24/139), and 2.8% (4/139), respectively. There were two cases of coinfection with A. platys and E. canis. The univariate analyses did not yield any associations between recorded variables and the active infection. Microscopic examination showed good sensitivity and agreement only for H. canis (Sn: 75%, 95% confidence interval: 24.9-98.7, κ=0.85).
Conclusion: Our findings confirmed the endemicity of the CTBPs in owned canine population in the study site. In-depth epidemiological investigation would be warranted to elucidate environmental risk factors for CTBP infection. Keywords: Anaplasma platys, canine tick-borne disease, Ehrlichia canis, Hepatozoon canis, polymerase chain reaction, thin blood smear.
Keywords: Anaplasma platys, canine tick-borne disease, Ehrlichia canis, Hepatozoon canis, polymerase chain reaction, thin blood smear.
How to cite this article: Tazawa K, Poolsawat N, Gibson AD, Gamble L, King A, Anuracpreeda P (2022) First study on molecular detection of three major canine tick-borne pathogens in subclinically infected dogs in Chiang Mai, Thailand, Veterinary World, 15(4): 1121-1128.
Received: 29-12-2021 Accepted: 31-03-2022 Published online: 28-04-2022
Corresponding author: Panat Anuracpreeda E-mail: panat.anu@mahidol.edu
DOI: 10.14202/vetworld.2022.1121-1128
Copyright: Tazawa, 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.