Escherichia coli (E. coli) is a naturally occurring bacterium found in the gut of chickens and many other animals. The body generally keeps this bacteria in check, but it can grow out of control, and some strains or serotypes can survive outside the host. Harmful strains of E. coli in chickens can lead to sickness, which can depress growth and production and ultimately transfer to people and other animals.
Pathogenic E. coli poses a significant threat to seniors, children, and people with compromised immune systems. Left unchecked, it can endanger other farm animals and customers who later purchase animals or consume byproducts. This could create serious public health concerns.
Thankfully, good farming practices can significantly reduce these risks. Let’s look more closely at what E. coli is, how it affects chickens, and what farmers can do to prevent it.
What is E. coli?
E. coli gets a bad rep as a bacteria that can cause colibacillosis. Even a small outbreak can devastate farms, supermarkets, and restaurant chains. It can also cause severe food poisoning and put people in the hospital.
Undoubtedly, an E. coli outbreak carries catastrophic risks, but the bacteria are typically harmless. In fact, it lives in the guts of humans and animals. According to the Centers for Disease Control and Prevention (CDC), scientists have found E. coli in our intestines, food, and the natural environment.
Most strains of this bacteria don’t pose a risk to humans, chickens, or livestock. However, a few strains can cause these and other illnesses in humans:
- Urinary tract infection
- Respiratory disease
When discussing E. coli in chickens, experts often refer to avian pathogenic Escherichia coli (APEC). APEC also infects ducks, turkeys, and other species of bird. APEC causes diseases in birds such as colibacillosis and other extra-intestinal illnesses like septicemia, air sacculitis, and pericarditis. .
How common is E. coli in chickens?
All healthy chickens have E. coli in their intestines, so it’s safe to say it’s common in almost all chickens. Chickens only risk developing colibacillosis when exposed to harmful strains.
Even then, happy and healthy flocks can typically fight an infection. In fact, scientists believe E. coli infections tend to occur when chickens’ immune systems are already taking a hit from other threats.
The possible transmission of APEC can occur by vertical transmission from the breeders and through horizontal transmission by food, air, litter, feces and other birds. Not surprisingly, poor husbandry is one of the top contributing factors. It can take the following forms:
- Constant exposure to other hazards, such as rodents
- Existing parasites, such as worms
- Poor nutrition
So, how common is an E. coli infection in chickens? One 2022 study in Poland found up to 38% of chickens carried a harmful strain. The risk was highest for commercial breeders but lowest in broiler chickens. Broilers had a 23% positivity rate.
The United States has much different meat and poultry processing and food safety requirements, but the prevalence is still high. The College of Agricultural Sciences at Penn State named E. coli one of the most common bacterial threats to poultry farms. A recent study in broilers found APEC like isolates in 144 samples out of 548 samples evaluated in a 32 day growout study.
How does E. coli affect chickens?
E. coli helps chickens break down foods and can defend them from other pathogens. However, dangerous strains have the opposite effect and can lead to localized or systemic infections. Chickens become infected after encountering other infected animals, such as new chickens added to the flock or droppings from wild birds.
E. coli symptoms in chickens
The pathogenesis of E. coli involves heavy colonization of a chicken’s gut, which can cause mild to severe symptoms. The type of strain, virulence, and each animal’s immune system play a critical role in fighting severe illness.
Knowing the symptoms can make diagnosing harmful E. coli strains easier, but infections can sometimes mimic other pathogens. In some cases, chickens might not show any symptoms. Examples of other diseases of poultry that E. coli may mimic include avian influenza, egg binding, Newcastle disease, and coccidiosis.
So, what are the first clinical signs of E. coli in chickens? The sequence of events can vary based on strain, but these are some common symptoms to look for:
- Respiratory illnesses in chicks, such as bronchitis and airsacculitis,Reproductive conditions, such as salpingitis and omphalitis
- Skin lesions or infections, such as cellulitis
- Cardiovascular symptoms, such as pericarditis
- Pelvic inflammation or perihepatitis
- Swelling of the stomach lining or peritonitis
- Blood poisoning or septicemia
- Higher-than-normal death rates
- Decreased egg production
- Distended abdomen
- Bloody droppings
- Reduced appetite
- Ruffled feathers
- Sudden death
- Poor growth
Can E. coli in chickens be treated?
E. coli doesn’t spell a death sentence for your flock, but it can be challenging to treat, and infected baby chicks typically don’t recover. Your treatment options will vary based on the virulence and type of E. coli affecting your chickens, so you may need to conduct tests to identify the culprit.
These are some critical steps to reduce E. coli prevalence and protect your flock:
- If you suspect illness, remove the infected animals from the flock and isolate them.
- Keep infected animals separate from the rest of the flock during treatment and only reintroduce them when you’re sure they’re healthy.
- Thoroughly clean and disinfect the chicken coop to remove residues of the bacteria.
- Replace the litter and take steps to keep it dry.
How E. coli is typically treated in chickens
Severe cases of colibacillosis will likely require veterinary care. Typically, your vet will administer or recommend antibiotic treatment. For example, your vet may recommend antibiotics such as tetracyclines, ampicillin, and streptomycin to control E. coli in the farm.
Note that some strains of E. coli have become increasingly resistant to antibiotics. The growing prevalence of resistant strains can have devastating effects on humans too. Scientists describe E. coli as one of the primary sources of antibiotic resistance, which is even more troubling.
To alleviate the effects of antibiotic resistance in E. coli, different alternatives to antibiotics such as probiotics can also prove effective against some gastrointestinal disorders. Consider using Engrain’s eMax Feed Technologies to improve intestinal health, reduce pathogens like E. coli, and boost growth performance.
How can E. coli be prevented among chickens?
E. coli can be a severe problem for chickens and farmers, but preventative measures can help keep your poultry healthy and ensure your farm’s success. You can effectively protect your birds from infection with proper hygiene practices, knowledge of E. coli symptoms in chickens, and a well-managed flock.
In other words, if you take good care of your chickens, they’ll take good care of themselves when diseases threaten their lives and your livelihood. Here are some best practices to consider:
- Follow the recommended vaccination and biosecurity program
- Use Engrain’s eMax Feed Technologies to create a nutritious and high-quality pellet or mash diet to reduce their susceptibility to poultry diseases.
- Use separate housing for new chickens, particularly if coming from unknown sources.
- Minimize contact between birds of different ages and sizes.
- Try not to overcrowd your flock.
- Ensure good ventilation throughout the house.
- Provide dry and clean bedding.
- Periodically monitor the flock for signs of E. coli infections.
- Keep your coops rodent-free to ensure healthy poultry production.
- Always provide clean drinking water, prioritize strict biosecurity measures by keeping wild birds away from your chicken coop.
- Implement a hatchery best practice to clean and disinfect eggs.
Discover how eMax Feed Technologies can keep chickens healthy
So, how do you take proactive steps to reduce the risk of E. coli infection in your flock? It may sound counterintuitive, but it starts with eliminating tetracyclines and other antibiotics from your feeding routine. For certain antibiotics, that has already been the law in the U.S. for several years, but international markets continue to lag.
Engrain’s focus extends beyond our fight against antimicrobial resistance by reducing the use of antibiotics in the diet. We help you reformulate diets to reduce the use of high levels of fat sources while still maintaining high energy levels to achieve the desired growth performance. Our internal studies have found that Engrain’s probiotics lower metabolizable energy requirements by up to 3% in broiler diets, reduce the cost of the diet without affecting egg production and weight gain, while also reducing Salmonella and E. coli risk of infection.