Hematological parameters of dogs for parasitism Dirofilaria immitis

The relationship between helminths and the host is built on a subtle molecular biological basis. Their pathogenic effect is characterized by the mechanical, toxic, inoculating effect on the host organism and the state of reactivity of his organism, immunological and allergic reorganization. It has been proved that helminths of the species Dirofilaria immitis are the most pathogenic nematodes of this genus because the localization of the imaginal stage of the parasite causes more complex pathogenesis of the invasion. The study aimed to establish changes in hematological parameters of dogs infected with D. immitis, considering the intensity of microfilariasis invasion. Studies have shown that the intensity of the invasion of up to 20 larvae/cm3 in the blood of dogs, significant changes in the number of erythrocytes, leukocytes, platelets, hemoglobin, and hematocrit and ESR were not found. The intensity of the invasion of 20–40 larvae/cm3 in infected dogs in the blood decreases the number of erythrocytes by 11.92 % (P < 0.05), the hemoglobin content by 16.33 % (P < 0.05), the hematocrit by 12.70% (P < 0.05) and the number of leukocytes increases by 15.17 % (P < 0.05). Indicators of the intensity of invasion of 40–60 larvae/cm3 in infected dogs showed more significant changes in the blood, which are characterized by a decrease in the number of erythrocytes by 25.54 % (P < 0.001), platelets by 34.03 % (P < 0.01), hemoglobin content by 30.86 % (P < 0.001), hematocrit by 20.56 % (P < 0.001) and an increase in the number of leukocytes by 32.75 % (P < 0.001) and ESR by 1.84 times 0.001). At indicators of the intensity of invasion of more than 60 larvae/cm3, in dogs significant (P < 0.001) decrease in the number of erythrocytes by 47.21 %, thrombocytes by 42.84 %, the content of hemoglobin by 42.27 %, the indicator of hematocrit by 41.57 % and an increase in the number of leukocytes by 44.98 % and ESR by 2.51 times. In the leukoform of dogs with increasing rates of microfilariae invasion, the number of eosinophils gradually increases to 62.38 % (P < 0.001), rod-shaped neutrophils to 27.48 % (P < 0.05), monocytes to 23.21 % (P < 0.01) and the number of lymphocytes is reduced to 45.45 % (P < 0.001). The data obtained indicate the importance of determining these indicators for heartworm disease, which complements the picture of clinical examination of animals and will allow more effective treatment of dogs in this invasion.