Avian salmonellosis is a group of diseases caused by bacteria from the genus Salmonella. Salmonella typhimurium is the most common paratyphoid infection found in birds. Illness or death in wild birds usually only involves small numbers of cases. This infection is a common "backyard bird feeder" disease that affects passerines such as house sparrows, pine siskins, American goldfinches, European starlings, and mourning doves. Outbreaks at bird feeders result from contamination of feeding platforms and feed by fecal deposits from Salmonella carriers in the population. Disease control at bird feeders is encouraged (cleaning a bird feeder).
There are no specific, distinct signs of avian salmonellosis paratyphoid infections in wild birds. Dead or dying birds at bird feeders are often thought to have been "poisoned" because of rapid death.
Related information: Field Manual of Wildlife Diseases