What is salmonellosis?
Salmonella spp. bacteria cause gastroenteritis—inflammation of the intestine—in animals, including humans and birds. These bacteria are carried normally by some birds, and can survive for long periods in soil and water. Ingested in water or food, salmonella bacteria cause abdominal distress with diarrhea, and sometimes spread to the blood and internal organs.
Salmonella infection usually strikes birds when they are stressed: when food is scarce, in extreme weather, when the weather is very hot, very cold, or even cool and wet. Spread through droppings, the salmonella bacterium passes easily among songbirds congregating at birdfeeders, and among flocks of water birds.
What are the symptoms of salmonellosis?
Birds infected with salmonella tend to huddle and may appear surprisingly tame. These sick birds shiver, appear unsteady, have drooping heads and wings, suffer from lack of appetite, and lose weight. They may appear excessively thirsty or they may not drink at all. Their droppings are yellowish or greenish and possibly bloody. Death is common.
Avoid spreading salmonella infection to your backyard birds
There’s always a danger of diseases spreading when birds congregate, but you can minimize the risks for your backyard birds. Start with a good birdfeeder—one that’s:
- made of plastic, metal, or some other material that can be easily washed and disinfected (not wood).
- a cylinder without a tray—this style doesn’t tend to become contaminated with bird droppings.
- small and easy to dismantle for cleaning and disinfection.
- designed so that seed is protected from rain.
You can also bake birdseed for one hour at 250F to kill contaminating organisms, though this will not necessarily destroy all harmful toxins produced by bacteria or molds.
Cleaning and disinfecting your birdfeeder
Even when the bird population is healthy, birdfeeders should be cleaned and disinfected every other week to minimize the chances of mold growth in the seed or contamination with harmful organisms:
- Dismantle the feeder if possible, discarding any remaining seed.
- Wearing rubber gloves, wash all parts thoroughly in a bucket or basin of hot soapy water. Use a brush to get into corners and crevices.
- Rinse the parts of the feeder thoroughly.
- Make up a solution of 10 percent bleach and soak the feeder parts for about ten minutes.
- Rinse the feeder very thoroughly in fresh water and allow it to dry completely before reassembling it and refilling it with seed.
- Clean up the ground below the feeder, removing decaying seed and debris.
- Wash your hands thoroughly with hot soapy water, and follow up with waterless hand sanitizer if possible.
DON’Ts for successful bird feeding:
- Don’t wash your birdfeeder in the kitchen sink. Salmonella bacteria and other disease causing organisms affect humans as well.
- Don’t fill a wet feeder with seed. Wet seed goes moldy and can make birds sick.
- Don’t fill your birdfeeder unless your birds will eat that much seed quickly. Keep adding fresh seed and clean the feeder regularly.
- Don’t feed birds when there is a disease outbreak that can be spread at feeders. If you must put a birdfeeder out, wipe it daily with 10 percent bleach or alcohol.
Bird baths can spread the salmonella bacterium and other diseases too. Refresh the water in your bird bath several times each week and clean the bath with 10 percent bleach every couple of weeks, just as you do your birdfeeder.
Related content:
Birds and Trichomonas gallinae
Sources:
Lavoie, Judith. “There's deadly bacteria lurking in your bird feeder.” Vancouver Sun,Sunday, June 03, 2007
Washington Department of Fish and Wildlife. “Bird feeding precautions urged to stem bird disease.”
