The incursion of raccoon rabies in the Hamilton ON area reached a total of 10 confirmed cases as of last week. A map of the current MNRF control zone is available on the OMAFRA website. This is the area where the Ministry of Natural Resources and Forestry (MNRF) has spread oral rabies vaccine (ORV) baits to help vaccinate the local wildlife (particularly raccoons, but also foxes and skunks) to try to contain the virus to as small an area as possible. Now that colder weather and some snow have finally arrived in southern Ontario, any further baiting efforts will likely be put off until the spring when these animals become active again.
Every time baiting is done, there are always members of the public that ask the obvious question: Will the baits work on other animals, like dogs and cats? This week I received a question regarding whether the baits could be used to vaccinate animals in a feral cat colony. While we certainly strive to get as many animals vaccinated as possible – particularly cats (even feral ones) and dogs that are more likely to have direct contact with people than most wildlife – the baits cannot be used to vaccinate domestic animals.
- The oral baits are specially engineered and tested to provide prot ection for foxes, raccoons and skunks. The developers of the vaccine and the baits have done extensive testing (which is ongoing) to show that these species will respond at particular levels in areas where baits are dropped. This requires special attention to the design of the bait (in order to attract these animals and get them to bite into the bait) and the vaccine itself (to make sure they get the right dose and in a way that produce an adequate immune response).
- While there is some interest in developing an oral vaccine for dogs for use in areas of the world where feral dog populations pose a major threat to people in terms of rabies transmission, there is still a lot of work to be done to design a bait and vaccine that will be safe and effective for this.
- Oral baits (to my knowledge) have never been tested in cats. Although cats certainly can get rabies and transmit it to people, they are not a rabies reservoir species, so research efforts with oral baits have focused elsewhere. It would be considered a poor use of resources to spread baits for cats rather than concentrating oral baiting efforts on the reservoir species in which we know the baits are effective. Also, because the baits are not designed to attract cats and are likely not an ideal size for many of them, it’s unknown if feral cats would chew on the baits in such a way that they would be exposed to an adequate dose of the vaccine – and of course we have no idea what an adequate dose for a cat is.
Injectable vaccines available for cats (and dogs) are extremely effective, and vaccinating feral cats that are captured for any reason in this way is the best way to protect them. Ensuring members of the public do not handle feral cats is also extremely important, as is making sure they contact public health if they are bitten by a feral cat. Vaccinating pet/house cats is one of the most important measures, as these cats have the most contact with people.
If you find a rabies bait, use gloves or a plastic bag (so you don’t get your scent on it) and move it to an area where wildlife are likely to find it. If your pet finds a rabies bait and you are concerned that it has been chewed, contact your veterinarian. OMAFRA has also put together a bulletin for veterinarians about the baits, as well as currently available (new!) options for rabies vaccination programs.
Happy New Year!