Canine Monocytic Ehrlichiosis: An Update on Diagnosis and Treatment

Abstract

Canine monocytic ehrlichiosis (CME) is a tick-borne disease of worldwide distribution. The major causative agent is Ehrlichia canis, a gram-negative, obligate intracellular, pleomorphic bacterium of the genus Ehrlichia, which infects monocytes, macrophages and lymphocytes, forming intracytoplasmic, membrane-bound bacterial aggregates, called morulae. After an incubation period of 8-20 days, the course of E. canis infection, can be sequentially divided into acute, subclinical and chronic phases, although these phases can hardly be distinguished in the clinical setting. Clinical recovery is the typical outcome of acutely infected dogs, entering the subclinical phase, during which they show no or minimal clinical signs and/or mild hematological abnormalities. Immunocompetent dogs may eliminate the infection during the acute or subclinical phases, but an unpredictable proportion of dogs will eventually develop the chronic phase, characterized by aplastic pancytopenia and high mortality, due to septicemia and/or severe bleeding. This article outlines briefl y the pathogenesis of CME due to E. canis, and more thoroughly reviews the recent scientifi c literature pertaining to the diagnosis and treatment of this devastating disease.

Effects of Doxycycline Treatment on Hematological and Blood Biochemical Parameters in Dogs Naturally Infected with Ehrlichia canis

“…Further studies on a larger group of dogs are necessary in order to clarify these findings. Hypergammaglobulinemia induced immune-mediated platelet destruction (8,9). Abnormal hematology findings are present due to tropism for hematopoietic cells and bone marrow hypoplasia, such as suppression in erythroid, myeloid, and megakaryocytic cells.…”

“…Canine monocytic ehrlichiosis, the disease caused by E. canis, is a multisystem disease characterized by three stages: acute, subacute and chronic stage. Clinical signs of the disease are various, but most often depression, anorexia, pyrexia and bleeding tendencies are present (9). Physical examination typically reveals lymphadenomegaly, splenomegaly and hemorrhagic tendencies, usually dermal petechiae and ecchymoses, as well as epistaxis.…”

A Retrospective Epidemiological Study: The Prevalence of Ehrlichia canis and Babesia vogeli in Dogs in the Aegean Region of Turkey

“…( Table 3). The infl uence of concurrent infections in the course of prognosis of infected animals was indicated previously [18,36]. However, in the present study, any possible effects of simultaneous infections on the clinical profi le of each co-infected dog were not investigated.…”

“…Ehrlichia canis is a pathogenic rickettsial organism causing canine monocytic erhlichiosis in dogs [3,36] with a world-wide distribution in tropical and subtropical regions [37]. Diagnosis of the disease caused by E. canis, could be challenging due to the variable spectrum of the disease and seasonal fl uctuations in the parasitaemia [15,36]. Conventionally, microscopy has been used to detect the organism in Giemsa stained peripheral blood mononuclear cells.…”

Frecuencia serológica de Ehrlichia canis en caninos sospechosos de ehrlichiosis en los distritos de Lima Norte, Perú

“…Algunos perros que poseen una inmunidad adecuada o con infecciones leves, pueden superar la fase aguda de la ehrlichiosis y llegar a eliminar a la bacteria sin tratamiento. Sin embargo, otros progresan a la fase subclínica, donde son asintomáticos o con signos clínicos leves, pero también pueden desarrollar la enfermedad crónica, con signos clínicos similares a los de la fase aguda, pero más severos, pudiendo afectar los tejidos hepático, renal y hematopoyético (Mylonakis et al, 2010).…”