Salmonellosis
Salmonellosis is a bacterial disease that infects a variety of species including mammals, reptiles and birds. There are many strains of the bacteria all belonging to the genus Salmonella. Salmonellosis is found in most avian species throughout the world, including North America.
TRANSMISSION
The bacteria that cause salmonellosis live in the intestinal tract of infected birds and are shed through feces. The organism can be spread from an infected bird to a healthy bird through direct contact or through the ingestion of food or water that has been contaminated with infected fecal matter.
In Wisconsin, outbreaks of salmonellosis are typically seen in songbirds, such as pine siskins, common redpolls, and finches, during late winter and early spring when birds are stressed and congregate around bird feeders and birdbaths.
CLINICAL SIGNS
Signs of salmonellosis vary greatly and are dependent on age, species, bacterial strain, and environmental stressors. Birds may show signs ranging from a gradual onset of disease to sudden death. Infected birds may appear "fluffed-up" and huddled together and maybe shivering. Many times, the first sign is finding multiple dead birds in a backyard where feeders are present.
DISEASE MANAGEMENT
Salmonellosis does not contribute to a substantial population decline in wild bird species and is more of an interest to individuals who provide bird feeders and birdbaths. Individuals can take simple precautions to reduce the risk of transmission of salmonellosis in wild birds.
- Clean feeders, feeding areas and birdbaths using a 10% bleach solution.
- Remove seed hulls under bird feeders.
- Move feeders occasionally to prevent the buildup of excrement underneath the feeder.
- Add additional feeders to reduce overcrowding and contamination.
- Keep seeds and food dry.
- Change the water in birdbaths regularly.
- If a sick or dead bird is found near a feeder or birdbath, remove the feeder or birdbath, wash and disinfect it using the 10% bleach solution and wait at least a week before putting it back up. If possible, move it to a new location.
If you find a group of dead birds, contact the DNR Wildlife Switchboard by emailing DNRWildlifeSwitchboard@wisconsin.gov or calling 608-267-0866. You will need to leave a message for the switchboard staff to return your call. In your message, please include the number of animals, the species (such as house finch), if they were sick or dead, the specific location where you saw them, including the county and your contact information.
PUBLIC HEALTH
The bacteria causing salmonellosis in wild birds do have the ability to infect humans. Humans can minimize the risk of infection by wearing disposable gloves and taking extra care in personal hygiene when handling materials soiled by bird feces, including feeders, birdbaths and birdhouses.