Haematological assessment of brucellosis in aborted sheep and goats in Proddatur, YSR Kadapa district of Andhra Pradesh

Introduction

Brucellosis is an important neglected zoonotic disease worldwide, causing considerable economic losses and serious public health risks. It is transmitted through direct contact with infected animals, consumption of contaminated animal products, or exposure to aborted materials, leading to abortions and infertility in animals and infecting humans, especially farmers and veterinarians (Mahboub et al., 2013) [6] . Haematological assessment helps in detection of anaemia, prognosis evaluation and enhancement of outcomes in infectious abortion scenarios. The level of haemoglobin was found to be decreased in affected group than control group (Hashem et al., 2020, Darwish et al., 2022 and Shareef and Albayati, 2023) [4,3&8] . Hashem et al. (2020) [4] reported increase in neutrophil and monocyte count in diseased group than control group, whereas lymphocytes, eosinophils and basophils were identical in both the groups. Darwish et al. (2022) [3] found increase in neutrophil, lymphocyte, monocyte and eosinophil count in the diseased group than control group whereas basophil counts were identical in both groups and both species. Shareef and Albayati (2023) [8] recorded increase in neutrophil and monocyte count in diseased group than control group, whereas lymphocyte was increased in control group and eosinophil, basophil count were identical in both groups. Naik et al. (2025) [7] noted increase in neutrophil, monocyte, eosinophil and basophil count in the diseased group than control group whereas lymphocyte count increased in control group.

Materials and Methods

The present study was carried out in various villages of Proddatur, YSR Kadapa district, Andhra Pradesh, India. Sample analysis was conducted at the Department of Veterinary Gynaecology and Obstetrics after obtaining prior approval from the Institutional Animal Ethics Committee (IAEC) under proposal No. 7R-CVSc, PDTR/IAEC/2025. A total of 120 blood samples were aseptically collected from aborted sheep and goats through jugular venipuncture across fifteen villages. About 2 mL of blood from each animal was transferred into Accutube EDTA K2-coated vacutainers, stored in an insulated ice box, and transported to the laboratory within three hours of collection. Haemoglobin and Differential Leukocyte Count (DLC) analyses were performed within 12 hours of collection. Haemoglobin was estimated using Sahli's method, while DLC was determined using Giemsa stained blood smear (Bernard et al., 2003) [2] . Statistical significance of haematological parameters was assessed using the t-test

Results

Haematological analysis (Table 1 & 2, Fig. 1 & 2) showed significant reductions (P < 0.01) in haemoglobin (Hb) in both sheep and goat. A statistically significant difference (p < 0.05) in monocyte count was observed between Brucella seropositive and seronegative sheep. In goats, neutrophil and lymphocyte counts showed significant differences (p < 0.05) between the two groups.

Discussion

In the present study, Brucella-seropositive sheep and goats exhibited significantly lower haemoglobin concentrations than seronegative animals, indicating the occurrence of anaemia associated with brucellosis. Similar reductions in haemoglobin levels have been reported by Hashem et al. (2020) [4] , Darwish et al. (2022) [3] and Naik et al. (2025) [7] , although Amin et al. (2009) [1] observed no significant differences. The decrease in haemoglobin may result from erythrocyte destruction mediated by immune responses against bacterial lipopolysaccharides (Tizard, 1992) [9] . Among differential leucocyte counts, a significant increase in neutrophils and a corresponding decrease in lymphocytes were observed only in seropositive goats, while no significant changes were detected in sheep. Comparable findings were reported by Darwish et al. (2022) [3] , whereas Hashem et al. (2020) [4] documented neutrophilia in infected ewes. These alterations may reflect inflammatory responses and oxidative stress associated with Brucella infection (Hussain et al., 2022) [5] . Monocyte counts were significantly reduced in seropositive sheep, suggesting suppression of cellular immune responses. This finding contrasts with reports of monocytosis in infected sheep and goats by Hashem et al. (2020) [4] and Darwish et al. (2022) [3] , who attributed increased monocyte levels to their scavenging role during uterine inflammation and retained placenta. Eosinophil and basophil counts did not differ significantly between seropositive and seronegative animals, which is consistent with previous observations by Hashem et al. (2020) [4] and Darwish et al. (2022) [3] . Overall, the haematological changes observed in the present study indicate that brucellosis can induce anaemia and alterations in leucocyte profiles, particularly in goats.

References

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