Like any animal, disease outbreaks can occur in wild birds. Unless they are large outbreaks they often go unnoticed, but smaller outbreaks can sometimes be encountered by homeowners with bird feeders. Because bird feeders are mixing sites for birds, they are also sites of disease transmission and a place where deaths can be identified. In an outbreak, feeders can contribute to the spread of infection between birds, and potentially be a source of infection for people or pets.
A classic example of this is Salmonella infection in songbirds. Outbreaks occur periodically and are often identified by people with bird feeders who start to find the odd dead bird in their yard. Some birds can be healthy carriers of the Salmonella bacterium (and therefore be a source of infection for others), while other birds may get sick and potentially die from the infection. If you have noted dead birds around a bird feeder, consider the potential for a disease outbreak, particularly salmonellosis.
The risk to people and pets from Salmonella outbreaks in birds is reasonably low, and probably greatest in cats. Most reports of songbird-associated salmonellosis (songbird fever) are in cats, because cats are more likely to catch and eat songbirds. Sick birds are easier to catch, further increasing the likelihood of exposure during an outbreak. Exposure is also possible through scavenging already-dead birds and perhaps from exposure to heavily contaminated surfaces or spilled feed around feeders.
General recommendations during an outbreak of salmonellosis in songbirds include:
- Keep cats indoors. This is a good idea at any time, but if you have an indoor-outdoor cat, keep it indoors if there might be an outbreak underway.
- If your pet has been exposed to a sick bird or an area where sick or dead birds have been found, and your pet gets sick, make sure you tell your veterinarian about the birds.
- Clean the bird feeder and then disinfect it by soaking it in 10% bleach for 30 minutes. Rinse it after the bleach treatment. If the feeder is difficult to properly disinfect (or you don't want to try), get rid of it by double bagging it and putting it in the garbage.
- When cleaning the feeder, do it outside so that you don't contaminate any household surfaces. When handling the feeder, wear disposable gloves and wash your hands after you remove the gloves.
- Keep the feeder down for 1-4 weeks. This reduces the concentration of birds in the area and may help reduce mingling of sick and healthy birds.
- Remove any dead birds by burying them at least two feet deep in a flowerbed (not in a vegetable garden!). This is not very easy or practical however - alternatively, double bag the bodies and put them in the garbage, avoiding direct contact with the birds and washing your hands afterward.