Assessment of the efficacy of oral vaccination of livestock guardian dogs in the framework of oral rabies vaccination of wild canids in Israel.

Since 1956, red foxes (Vulpes vulpes) and golden jackals (Canis aureus) have been the primary vectors maintaining wildlife rabies in Israel. Oral rabies vaccination of wild canids, initiated in 1998, resulted in near-elimination of the disease in wildlife by 2005. In 2005 and 2006, an outbreak of rabies was observed in stray dogs in the vaccinated area of the Golan Heights, with no cases in foxes or jackals. Epidemiological investigations showed that the infected dogs were from territories across the border. This was confirmed by molecular analysis, which showed that the virus was different from rabies isolates endemic to this area. The objective of this study was to determine bait acceptance and the feasibility of oral rabies vaccination in packs of livestock guardian dogs. Coated sachets and fishmeal polymer baits of Raboral V-RG (Merial, USA) were tested in five different test zones. Both formats were hand-fed to individual dogs and to dogs belonging to dog packs. Bait uptake and consumption were observed in each dog. The estimated efficacy of oral rabies vaccination was very low (a maximum of 28%). Vaccine delivery problems were observed in dogs belonging to packs, whereby dominant animals consumed multiple baits and in competitive situations baits were swallowed whole. The uncertainty of oral vaccination necessitated turning to other methods to control this outbreak: stray dogs were removed and herd dogs were vaccinated parenterally. This study showed that oral rabies vaccination of dogs in packs using baits designed for wildlife would not be effective. Possibly, different baits or steps to circumvent competition within the pack will make this approach feasible.