Molecular prevalence and haemato-biochemical profile of canine monocytic ehrlichiosis in dogs in and around Hisar, Haryana, India

Abstract

The present study was planned to investigate the molecular prevalence of canine monocytic ehrlichiosis (CME) in dogs in and around Hisar and to evaluate the haemato-biochemical profile for its better management. A total of 60 dogs presented to Medicine Section, TVCC, LUVAS, Hisar with the history of naturally acquired tick infestation and clinical signs consistent with CME were screened on the basis of blood smear examination, followed by molecular detection by nested PCR assay targeting a portion of 16S rRNA gene of . Nested PCR detected 18 cases positive for with estimated 30% percent positivity as compared to 8.33% (5 out of 60) by blood smear examination. These 18 dogs confirmed for CME by nested PCR were assessed for clinical and haemato-biochemical profile. Breed-wise prevalence indicated maximum number of cases in Labrador retriever, followed by Pug, Rottweiler and German shepherd dog with more number of cases in male dogs. Age-wise prevalence revealed highest number of cases in more than 1 year age group, followed by 6 months to 1 year age group and least in less than 6 months aged dogs. Pyrexia, anorexia and pale to congested mucous membranes were the main clinical signs observed, followed by lethargy, vomiting. Less common clinical signs were epistaxis, lymphadenomegaly, hind limb weakness, malena, ocular discharge, followed by haematuria, corneal opacity, nasal discharge and coughing, icterus, dermal petechiae and ecchymoses. The haematological profile revealed macrocytic hypochromic anaemia, thrombocytopenia, normal leucocyte count with relative lymphocytosis, monocytosis and neutropenia. Serum biochemistry revealed significant rise in values of ALT, AST, GGT, bilirubin total, bilirubin indirect, alkaline phosphatase and A/G ratio in affected dogs as compared to healthy control, suggesting the hepatic dysfunction. The lipid metabolites and kidney function parameters were non-significantly altered from those of healthy control. A high positivity for detected by nested PCR in dogs in and around Hisar suggests the endemicity of the disease in dogs' population in this region and warrants the screening for the disease in suspected dogs by this technique as compared to routine blood smear examination. The presented haemato-biochemical profile may be useful in presumptive diagnosis of the disease in dogs and their better clinical management.

Efectividad de los métodos diagnósticos para la detección de ehrlichiosis monocítica humana y canina

“…Este método presenta ciertas desventajas como lo son su baja sensibilidad, atribuido principalmente a la baja bacteriemia, implicando una mayor inversión de tiempo para la búsqueda de mórulas, lo que dificulta su identificación. Por otra parte, las mórulas se pueden observar únicamente durante la fase aguda de la enfermedad cuando la bacteria se multiplica en microcolonias intra-citoplasmáticas 17,[20][21][22] .…”

Demonstrating the presence of Ehrlichia canis DNA from different tissues of dogs with negative PCR in blood

“…Identi cation of morulae in monocytes in a blood smear is diagnostic of the disease; however, a low frequency of morulae in buffy coat smears has previously been reported, which could be due to the low parasitaemia observed in the natural infection [7,11,[16][17][18][19][20][21]. Besides, other more speci c methods are used as diagnostics, including the immuno uorescence antibody test (IFA) and ELISA (enzyme-linked immunosorbent assay), which are both able to detect speci c antibodies [21][22][23][24][25][26][27], as well as other molecular techniques such as the polymerase chain reaction (PCR) [1,19,[28][29][30][31][32][33][34][35][36].…”

Demonstrating the presence of Ehrlichia canis DNA from different tissues of dogs with negative PCR in blood

“…Identification of morulae in monocytes in a blood smear is diagnostic of the disease; however, a low frequency of morulae in buffy coat smears has been reported previously. It could be to the low parasitaemia observed in the natural infection [7,11,[16][17][18][19][20][21]. Besides, other more specific methods are used as diagnostic, including the immunofluorescence antibody test (IFA) and ELISA (enzymelinked immunosorbent assay), which are both able of detecting specific antibodies [21][22][23][24][25][26][27].…”