Epidemiological Investigation of Anaplasmosis

Abstract

Bovine anaplasmosis is a tick-borne disease of significant veterinary and economic importance in tropical livestock systems. The present study was conducted to determine the prevalence of anaplasmosis in crossbred cows in and around Mhow, Madhya Pradesh, over a period of twelve months. A total of 100 crossbred cows from the Livestock Farm Complex of the College of Veterinary Science and Animal Husbandry, Mhow, and from private dairy farms in the surrounding area were included in the study, yielding 1,200 animal-observations across the study period. Diagnosis was confirmed through microscopic examination of Giemsa-stained thin blood smears. The overall prevalence of anaplasmosis was 15.75%, comprising a clinical prevalence of 4.25% and a subclinical prevalence of 11.50%, with subclinical cases consistently outnumbering clinical cases across all months. The highest monthly clinical incidence was recorded in June (17%), while subclinical cases peaked in May (25%); the lowest rates were observed during December and January. Seasonal analysis revealed that the summer season (March–June) recorded the highest prevalence of both clinical (9.75%) and subclinical (19.25%) cases, a difference that was statistically significant (p = 0.0186). Age-wise analysis demonstrated a statistically significant association (p = 0.039) between age group and disease occurrence, with crossbred cows aged five years or younger exhibiting markedly higher subclinical prevalence (14.69%) compared to older animals (7.59%), while clinical prevalence was comparable between the two groups. Breed-wise analysis revealed no statistically significant difference between crossbred Holstein Friesian and Jersey cows (p = 0.964). Although no statistically significant associations were established between disease prevalence and housing type or hygienic conditions, higher infection rates were consistently observed in animals maintained in kaccha housing and under poor hygienic conditions. These findings underscore the role of environmental and management factors in the epidemiology of bovine anaplasmosis and highlight the importance of regular surveillance, vector control, and improved husbandry practices for effective disease management in dairy cattle populations.