The Seasonal Occurrence of Haemorrhagic Anaemia in Goats

Abstract

Cross sectional haematological studies were conducted in goats on a small ruminant farm at Malya in Mwanza, Lake Victoria basin, Tanzania. The purpose was to determine the causes and magnitudes of anaemias in tropical ruminants and the seasonal occurrences. Number of helminth eggs per gram of faeces was parallel determined. The commonest cause of anaemia was observed to be helminthiasis, which occurred in the rainy months of February, March and April. The number of clinically sick goats increased in March and April, causing mortality rates of 30.5 %. Haematocrit, haemoglobin concentration and number of erythrocytes in goats infected with helminths were lowest in the rainy months of March, April and May. During these months packed cell volumes (PCV) were 0.24±0.05, 0.22± 0.06 and 0.24±0.031/L respectively. The respective erythrocyte counts in March and April were 9.76±2.16 and 8.90±2.69 and restored to 15.90±1.55 in May. Haemoglobin concentrations were 4.50±62, 4.00±1.58 and 5.08±0.55 mmol/L in March, April and May respectively. The number of worm eggs per gram of faeces in the same months was 6469±3899, 577±3495 and 3615±1240 respectively. Total serum proteins and number of leukocytes were highest during the wet months of March, April and May. The protein levels were 114.2, 108.2 and 103.8 g/L respectively. The respective leukocyte counts in March to May were 20.1±6.66, 32.8±3.97 and 16.3±6.10. These were lowest during the dry period in June, August and September. Protein concentrations in these months were 75.4, 72.6 and 75.9 g/L respectively. The respective leukocyte counts were 13.9±4.70, 14.3±4.90 and 15.0±2.46. Blood cells during anaemic phases in the rainy period were macrocytes, poikilocytes and acanthocytes while during the dry months they were normocytes and spherocytes. These findings unequivocally reveal that anaemia in tropical livestock occurs in wet months as a result of iftcteases in internal parasitic burden.