TEST OF 3 BAIT TYPES FOR ORAL IMMUNIZATION OF DOGS AGAINST RABIES IN TUNISIA

Chicken heads and two types of artificial bait were tested in Tunisia during two field trials in a waste disposal site carried out in 1988 a nd 1989 to compare their effectiveness as vehicles for the oral admini stration of antirabies vaccine to free-roaming dogs. Baits were made a vailable for 36 hr and those that disappeared or were consumed were re placed on several occasions. In 1988, an artificial bait composed of f at and fishmeal (artificial bait type I) was tested. In the second tri al, chicken heads and an artificial bait composed of polymerized fishm eal and wax (artificial bait type II) were compared. The vaccine conta iners were loaded with a topical marker (rhodamine B or methylene blue ) to identify animals that had consumed baits. The artificial type I b ait tested in 1988 was poorly accepted, but in the second trial, the n umber of chicken-head baits probably taken by dogs was more than seven times greater than the number of artificial type II baits taken. Thir teen dogs observed during the day showed topical marker staining. In b oth trials, most baits were taken during the night when dog activity i n the waste disposal site was at its maximum. Artificial baits were ch aracterized either by their lack of thermostability (type I, melting) or a certain attractiveness for cats (type II, fish flavor). Chicken h eads fulfill established requirements for baits for vaccine delivery. They are well-accepted by free-roaming dogs, inexpensive, usually easi ly available at local markets, unattractive to humans, relatively easy to store in large quantities, and easy to handle.