First Molecular Detection and Phylogenetic Analysis of Ehrlichia canis in Dogs from Baghdad, Iraq.

Abstract

Ehrlichia canis is a pathogen considered a disease in both dogs and breeders, a tropical and non-tropical disease caused by an intracellular pathogen. For the first time, the study aimed at hematological and molecular detection and phylogenetic analysis of Erlchcia canis in dogs in Baghdad, Iraq. Two hundred dogs were clinically examined from April to September 2019 at the Veterinary Hospital in Baghdad. Blood samples with EDTA tubes were used for microscopic examination, complete blood count (CBC) and polymerase chain reaction (PCR). The study's results revealed that the infection rate was 3.5% when analyzed using microscopic or molecular methods. Ataxia, posterior recumbency, and occasionally vision problems were identified as the clinical characteristics that were distinguished in this study. The hematological values showed no significant differences between infected and uninfected dogs (P>0.05). However, the study did show that infected dogs had neutrophilia and monocytosis. Four samples were sent to the sequencers, and NCBI accession numbers were assigned to two isolates of the Ehrlichia canis 16s rRNA gene (MN227483.1 and MN227484.1). This study showed that 99% of the isolates matched those found in other countries. The study concluded that microscopic examination is not the best method for diagnosing Ehrlichia in dogs because it requires the ability to differentiate microscopically between intracellular inclusion bodies and the included morula of Ehrlichia and may produce incorrect results. Instead, molecular tests are used to confirm an Ehrlichia diagnosis.