Investigations of significance of blood smear results in diagnostics of infectious and parasitic diseases in dogs

Abstract

The microscopic examination of stained smears of peripheral blood is of vital significance in the speedy diagnostics of infectious and parasitic diseases, in particular during the stage of infection when the cause is present in the blood, or blood cells. It is sometimes possible to make a definitive diagnosis of an infectious or parasitic disease following an examination of a stained smear of the peripheral blood. Since microscopic examinations of a peripheral blood smear are applied increasingly rarely in clinical practice, due to the development of other methods for the diagnostics of infectious and parasitic diseases in dogs, as well as the lack of knowledge of the morphology of the numerous causes that can be present in the blood, we carried out an investigation into the presence and spread of infections whose causes can be present in dog blood. The investigations covered 100 dogs from which peripheral blood smears were taken and then stained with a Giemsa solution according to the standard protocol and examined under a microscope with an immersion lens. The examination of peripheral blood smears stained according to Giemsa resulted in the identification of the presence of an Ehrlichia spp. morula in a neutrophil granulocyte in one dog. The presence of hemotropic mycoplasmas was established in erythrocytes of eleven dogs, while the presence of the protozoa Babesia canis in erythrocytes was identified in five dogs included in the investigations. A microscopic examination of dog peripheral blood smears stained according to Giemsa was shown as a speedy, practical, simple, and inexpensive method for making a definitive etiological diagnosis of these infections, and it should be included regularly in standard protocols for the diagnostics of infectious and parasitic diseases.