Evaluation of the FAMACHA system for detecting the severity of anaemia in sheep from southern Italy

Since it was first developed in South Africa, the FAMACHA system has been successfully tested in different geographic area where Haemonchus contortus is the major gastrointestinal (GI) strongyle species of sheep. The present study, the first on the use of the FAMACHA system in Italy, was aimed at obtaining a complete haematological profile in sheep with GI strongyle infection, in order to evaluate the validity of the FAMACHA system for detecting the severity of anaemia in sheep from southern Italy. Between April and September 2006, 793 blood and faecal samples were collected from 137 adult sheep of different local breeds of the Campania region (southern Italy). Each study animal was monthly subjected to blood collection, GI strongyle fecal egg counts (FEC) and a complete clinical examination, with particular attention to the colour of ocular mucous membranes. The FAMACHA score values (from 1 to 5) were compared to Hematocrit (Hct) and Haemoglobin (Hb) values. Considering the FAMACHA score number “3” as borderline value for anaemia, the eye score values for anaemic animals were considered in the categories of 4 and 5 (Group 4-5) or of 3, 4 and 5 (Group 3-4-5), respectively. Anaemia due to GI strongyle infection was considered when the Hct and/or Hb values were under 27% and 9g/dl, respectively. The correlation between FAMACHA score and both Hb and Hct was significant (P <0.001) and negative; however, the low correlation coefficients indicated a weak negative association between FAMACHA and either Hb and Hct parameters. The sensitivity, specificity, predictive negative value (NPV) and predictive positive value (PPV) of the FAMACHA system were calculated. The highest values of sensitivity were 66% and 60% in the Group 3-4-5 for Hct and Hb, respectively. The highest values of specificity were 98% in the Group 4-5, for Hb and Hct, respectively. In the Group 3-4-5, the specificity was 60% and 62% for Hb and Hct, respectively. The NPV was 92% (Hct) and 84% (Hb) in the Group 3-4-5, while it was 87% (Hct) and 78% (Hb) in the Group 4-5. The PPV, for the others categories considered (Hb, Hct, Group 4-5 and 3-4-5), was always below 54%. In conclusion, in the present study, the FAMACHA system showed a low sensitivity in detecting anemic sheep; these findings indicate that in southern Italy, under our experimental conditions, FAMACHA may represent an additional element that can integrate clinical examinations. It is important that such evaluations are performed in each region before the system is implemented, as there could be local issues that affect the accuracy of the system.