Prevalence and Haematological Correlates of Anaplasmosis in Cattle at Gwagwalada Abattoir, FCT Abuja

Anaplasma marginale infection, transmitted by Rhipicephalus ticks, causes significant morbidity and economic losses in cattle across the North Central geopolitical zone of Nigeria, including the Federal Capital Territory. Diagnosis is complicated by subclinical infections that may not present with obvious clinical signs yet result in progressive anaemia and reduced productivity. This study determined the prevalence of Anaplasma marginale in cattle slaughtered at the Gwagwalada Abattoir, Abuja, and characterised associated haematological alterations. Blood samples were collected from 100 cattle at the point of slaughter. Thin blood smears were prepared and examined microscopically for the characteristic marginal inclusions within red blood cells. Polymerase chain reaction targeting the major surface protein 5 gene was also performed. Haematological analysis was conducted using an automated haematology analyser. Microscopy detected Anaplasma marginale in 23 percent of samples, while PCR positivity was higher at 38 percent, highlighting limitations of microscopy alone for diagnosis. PCR-positive animals showed significantly lower PCV, haemoglobin, and red blood cell counts compared with negative animals. Mean PCV in positive cattle was 21.3 percent compared to 31.8 percent in negative animals. Thrombocytopenia was present in 64 percent of PCR-positive cases. These findings indicate a substantial prevalence of anaplasmosis at the Gwagwalada Abattoir and its association with significant anaemia, underscoring the need for surveillance and tick control programmes in the FCT and surrounding North Central states. Keywords: anaplasmosis, cattle, haematology, Gwagwalada, PCT.