Assessing the burden of gastrointestinal nematodes and their susceptibility to Ivermectin in goats slaughtered in Uganda Meat Industries Limited,Kampala District

Abstract

Gastrointestinal nematode (GIN) infections are one of the major causes of production losses in commercial goat farms worldwide, the deadliest in goats being Hemonchus contortus because of its blood sucking nature. Recent reports suggest that there is irrational use of antihelmitic drugs such as Benzimidazoles which has led to evolution of multi-resistant species of GIT nematodes hence ineffective control of GINs. This study therefore, determined the burden of GINs and their susceptibility to ivermectin in goats slaughtered in Uganda Meat Industries Limited, Kampala district. A total of 50 goats were randomly selected and fresh contents from their GIT were collected after their slaughter from the abattoir. Laboratory analysis was done using floatation, sedimentation and McMaster techniques to identify and enumerate the nematode egg types. Larval cultures were done to grow eggs into larvae after 21 days of incubation at room temperature, Baerman’s technique was carried out to isolate the larvae from the coprocultures and larval motility inhibition tests were done to assess GIN susceptibility to IVM. The highest egg per gram of fresh GIT contents was 4300 and lowest was 50. The highly frequent GIN genera were Trichostrongylus larvae, 62% (31/50) followed by Cooperia larvae, 38% (19/50) and then Hemonchus larvae, 30% (15/50), Nematodirus larvae, 12% (6/50) and the lowest being Ostertagia, Bunostomum and Oesophagostomum larvae with a frequency of 8% (4/50) each. The 1mg/ml of ivermectin killed 100% of the GIN larvae but the serial dilution with the highest ivermectin concentration (0.5mg/ml) killed 88.8% of the larvae after paralysis and the lowest diluted ivermectin concentration (5×10-8 mg/ml) killed 0% of the larvae however, they were paralyzed thus susceptibility of GINs to Ivermectin but the larvae (L3) in five control experiments were neither killed nor paralyzed after the 3 days of observation. The probit analysis indicated that LC95 was 0.5186mg/ml with Standard Error (SE) of 0. 0032. Therefore, LC95 when GINs were exposed to ivernectin in vitro was in the range of 0.5154 -0.5218mg/ml at 95% confidence interval. In conclusion, the GIN burden was high (90%) and therefore, routine deworming with ivermectin should be adopted by goat farmers.