Sugar Feather Farm always likes to bring you useful and important information. We recently did a study with Andrea Etter of the University of Vermont here on our farm. She is doing a study on Salmonella in chickens. We were pleased to find our flock from newborn up, was not carriers at the time of testing of salmonella! We were very pleased with the results and feel this is an important finding to share. Salmonella in your flock is a real thing and awareness is key.
Salmonella and chickens
Salmonella enterica is a common intestinal bacterial species in domestic and wild birds, mice, other rodents, cows, pigs, and many other animals. Salmonella gets along especially well with poultry, often not causing any observable symptoms. Unfortunately, humans who accidentally ingest Salmonella will typically develop diarrhea, cramping, and potentially nausea and vomiting and a fever. Rarely, people infected with Salmonella will develop blood infections (septicemia) or other severe conditions. About 20% of people infected with Salmonella will be hospitalized, largely because they will become dehydrated from diarrhea and/or vomiting. Children, immunocompromised people, and people over 65 are most likely to become seriously ill and be hospitalized.
There are about 2,500 different serovars (distinct types) of Salmonella, with about 20 different types causing 75% of illnesses in the United States (this is why we don’t have a vaccine for Salmonella at this point). Getting Salmonella once only protects you fully against the type of Salmonella you had and you can still get sick if you encounter a different type of Salmonella later.
Chickens carry Salmonella in their intestines and in the follicles of their feathers (this is partially due to dustbathing habits). However, because they both poop and lay eggs out of their cloaca, there is a connection between their intestines and their uterus/shell gland. Salmonella can use this connection to travel into the uterus and infect the egg before the shell develops. This means chicks can be born with Salmonella, which they got from their mom through the egg. Chicks (and adults) can also get Salmonella from infected feed or water, contact with wild animals/birds or their droppings, and interacting with other chickens/poultry who have Salmonella. Most chicks will get better from Salmonella after a short time (days/weeks), but a few will continue to carry Salmonella up through adulthood and egg-laying. Adults can also get Salmonella as adults; they can clear out the infection after a week or two.
The main way humans get Salmonella from chickens/poultry are through either eating poultry meat/eggs that are contaminated with Salmonella or through handling infected live poultry or eggs. Chicks seem to be the highest risk for Salmonella. Our research shows that roughly 8% of chick shipments from hatcheries who don’t monitor/test for Salmonella contain Salmonella. Unfortunately, chicks are adorable, so they get handled a lot by their owners/owners’ kids, which is a prime opportunity for them to pass on Salmonella.
There are a few simple precautions owners can take to reduce their opportunities for getting Salmonella from their chicks and adult chickens.
- Don’t kiss chicks or chickens. If they have Salmonella on their feathers, this is a great way to get it in your mouth
- Wash your hands thoroughly after handling your chicks or chickens or their eggs (eggs and poop come out the same hole, so even clean-looking eggs can be contaminated)
- Supervise kids around chicks/chickens. Make sure they don’t kiss the chickens and that they wash their hands afterwards
- Wear different shoes in the chick pen than you wear indoors, so you don’t track poop and Salmonella indoors (Salmonella can survive in dried poop, too)
- Wear a mask when you clean your coop to avoid inhaling dried manure dust and Salmonella
Dr. Andrea Etter is originally from rural Wisconsin and grew up on a small homestead with chickens, goats, sheep, horses, and turkeys (among other animals). She got her PhD in microbiology and food safety at Purdue University, where she studied how Listeria monocytogenes colonizes grocery store delis and investigated whether Salmonella Heidelberg strains involved in an outbreak of foodborne illness were unusually good at surviving bacterial control measures= in poultry processing plants. Andrea began as an assistant professor at UVM in January 2019 and continues to study food safety. Along with researching Salmonella and Campylobacter levels in backyard chickens and chicks, her lab studies Listeria monocytogenes from Vermont dairy surfaces and Salmonella from other foodborne outbreaks. Andrea also teaches two courses on food safety and enjoys horseback riding, gardening, and fiber arts in her spare time.