Famacha method as a tool for selective control of nematode parasites in sheep

Abstract

ABSTRACT. Hassum I.C. Famacha method as a tool for selective control of nematode parasites in sheep. [Famacha como ferramenta de controle seletivo da verminose em ovinos.] Revista Brasileiro de Medicina Veterinária, 36(3):251- 254, 2014. Parasitologia/Saúde Animal, Embrapa Meio-Norte, Avenida Duque de Caxias, 5650, Bairro Buenos Aires, Teresina, PI 64006-220, Brazil. E-mail: [email protected] Worms constitute a serious health problem that affects sheep herds worldwide, causing significant economic losses and limiting productivity. Haemonchus contortus nematode is considered the most important in this context, and control based solely on the use of anthelmintics has not been efficient. Thus, the use of an individual clinic diagnostic methods, such as Famacha, can be a strong ally in the desired control. The study was conducted at Embrapa Southern Region Animal Husbandry, in Bagé, Rio Grande do Sul, Brazil, during the months of March 2009 to April 2010. Pure and crossbred sheep were studied, both male and female, young and old, bred extensively in natural field. The animals were evaluated at intervals ranging from seven days (minimum) to 15 days (maximum), and the treatment was applied to individual animals classified as Famacha grade three, four or five. Additionally, from a total of 27 evaluations, 17 were followed by blood collection for analysis of Packed Cell Volume (PCV) and 20 by individual stool collection. Throughout the evaluation period, H. contortus was predominant in the stool. There was negative correlation (r = -0.454, p ≤ 0.05) between Famacha and PCV, and low positive correlation between Faecal Egg Count (FEC) and Famacha (r = 0.185, p ≤ 0.01). On average, 80.5% of the assessments based on Famacha method were correct. It has proved to be a complementary alternative to the selective control of nematode parasites in sheep, reducing the number of applications of anthelmintics and preserving the population of parasites in refugia.