Evaluation of plant extracts to control haemonchosis in naturally infected sheep

Abstract

Sheep husbandry is considered an important economic practice in Brazil. However, there are problems associated with this practice. Haemonchosis stands out among these, and is known among sheep farmers for being a difficult disease to treat. Haemonchus contortus is considered the main helminth parasite of sheep, due to the fact that it is the only direct blood-sucking parasite, which can cause anemia, weight loss, submandibular swelling (mumps), low quality of meat and wool, and death of a large percentage of the herd. Currently, the predominant treatment is allopathic medicines, but resistance is increasing due to their repetitive use. In this sense, herbal medicine has emerged as a promising alternative. This study therefore aimed to evaluate the in vivo anti-parasitic activity of three plant extracts: hydroalcoholic extracts obtained by the percolation of Lepidium didymum and Momordica charantia and aqueous extract of Tagetes minuta. Animals of the Santa Inês breed were screened to identify parasitized specimens and separated into four groups of six animals each. One was used as an untreated control group, and the others were treated with 200 mg/day (5 mg/kg body weight) of the three extracts for 5 days. After treatment, EPG (eggs per gram of feces) was determined by the Mac Master method with modification. The animals in the groups treated with extracts of L. didymum and M. charantia showed a significant reduction (p <0.05) of EPG. These extracts may therefore be useful in the treatment of sheep haemonchosis.