CLINICAL AND LABORATORIAL ALTERATIONS AS INDICATORS FOR ANTI-HELMINTIC TREATMENT IN SHEEP EXPERIMENTALLY INFECTED WITH Haemonchus contortus

Abstract The intensity of anemia and hypoproteinemia are indicators of the seriousness of haemonchosis. The objective of this study was to verify the changes in weight, hematocrit, and plasma protein, as well as the parasite load, indicating the need for anthelmintic intervention in sheep experimentally infected with Haemonchus contortus. Fourteen crossbred Santa Inês male sheep were used, weighing 42.5 (± 7.5) kg, nematodes-free. The animals were divided into two groups of seven animals each. The group of infected animals received 10,000 H. contortus larvae each. All animals were monitored after 21, 28, 35, 42, 49, 56, 63, and 70 days post-infection and the following parameters were assessed: EPG, Famacha©, weight, total plasma proteins, and hematocrit. In the infected group, the EPG varied and peaked on the 42nd follow-up day. The hematocrit became significantly lower after the experimental infection. Famacha score© ranged from 1 to 2 and it was significantly higher at 21, 28, 35 and 42 days. No change was observed in plasma protein level and body weight in the control group. Infection with up to 10,000 larvae of H. contortus. and EPG up to 2500 did not significantly affect weight, hematocrit, and plasma protein of crossbred Santa Inês sheep with no need for anthelmintic intervention.