Effect of different methods of administration of ivermectin on its efficacy against the shedding of gastrointestinal nematode eggs by gazelles

Seven different methods of administering ivermectin to gazelles were compar ed: subcutaneous injection, direct oral administration, administration in i ndividual feeds, administration in a herd feed, direct oral administration of a second ivermectin formulation, administration in individual water supp lies, and administration in the herd's water supply. The first five treatme nts were effective, as monitored by faecal egg count reduction tests, and a dministration in individual feeds or in a herd feed avoided the need to cap ture the animals, with the attendant risk of mortality Of the factors assoc iated with the recipients (species, sex, age and inbreeding coefficient) ag e was the only significant factor for the efficacy of the treatment. Oral o r subcutaneous, individual or collective, and direct or indirect administra tions were equally satisfactory for the treatment of all the parasite group s studied. only when parasitic problems were due to Nematodirus species did direct administration to individual animals appear to be preferable.