Why are chickens given antibiotics?

It’s no secret that factory farms pose a risk to public health. Not only are they widely considered to be the likely source for the next global pandemic, but they’re also drivers of an equally significant threat: antibiotic resistance.

Many bacteria that are already resistant to antibiotics claim hundreds of thousands of human lives every year. And yet, antibiotics are given to farmed animals, including chickens, who aren’t sick, to prevent disease.

In fact, around two thirds of the world’s antibiotics are now given to farm animals. It’s an issue on a huge scale, but why do chickens even need so many antibiotics?

Why are antibiotics given to chickens?

Just like us, chickens fall sick, and antibiotics are used to treat them. However, on factory farms, antibiotics are also often given to healthy chickens in order to prevent disease. While that may sound like a good thing, this practice can encourage bacteria to mutate and become antibiotic resistant.

Preventative antibiotics are given to animals because factory farms are filthy, with thousands of birds living together in sheds. Without the heavy use of antibiotics, modern day factory farms would not be possible, as diseases would spread often and rapidly through the massive flocks.

Chickens on factory farms are also genetically very similar to each other, making them more susceptible to disease spread. This lack of genetic diversity can be attributed to the generations of birds selectively bred with the singular goal of increasing productivity.

In some countries outside the UK, antibiotics are also given to chickens to encourage growth. In the UK, antibiotics used exclusively for this purpose are banned for use on farms.

What antibiotics are used on chickens?

There are a variety of antibiotics given to chickens on farms across the globe, including:

• Aminoglycosides. Neomycin, gentamicin, and tobramycin are examples of aminoglycosides, most often used to treat eye infections. Historically, this class of drugs has been highly effective against E. coli. However, on industrial farms E. coli is adapting to be resistant to the drug.
• Bambermycins. Specific to veterinary medicine, bambermycins are given to chickens to encourage weight gain.
• Ionophores. Ionophores are most commonly given to chickens to prevent coccidia - an infection caused by protozoa. Experts view ionophores as a major enabler of modern factory farms; without the drugs, coccidia would run rampant and make large-scale production impossible.
• Lincosamides. Clindamycin is a common lincosamide, used heavily to treat infections in both human and veterinary medicine.
• Macrolides. Macrolides are considered critically important in both human and veterinary medicine. Already, researchers are seeing resistance to this class of drugs manifesting in bacteria.
• Quinolones. Another class of drugs that’s critically important for people, quinolones are used to treat respiratory diseases and other infections in chickens.
• Streptogramins. Researchers have already identified bacteria resistant to virginiamycin - a drug in the streptogramins class. A higher occurrence of resistant bacteria has been found in omnivorous patients than in vegetarians, and in conventional chicken than in antibiotic-free.
• Sulfonamides. Sulfachloropyridazine is one sulfonamide that is marketed to poultry farmers to prevent bacterial diseases in their flocks.

Does chicken meat contain antibiotics?

The chicken wings or fillets you get at the grocery store likely do not contain traces of the antibiotics they’re fed. But that doesn’t mean you’re not being impacted by the use of antibiotics on farms. In fact, on-farm use of antibiotics is one of the major drivers of antibiotic resistance, which killed over 1.2 million people in 2019.

Raw meat can contain antibiotic-resistant bacteria. A recent study found that 100% of chicken meat sampled had E. coli on it that was resistant to some antibiotics, and nearly half of them had E. coli that was resistant to antibiotics considered critically important.

Antibiotic resistance means that a growing number of bacteria are increasingly able to resist the drugs that would have at one time eradicated infection.

As a result, the World Health Organization recommended in 2017 that antibiotics on farms be reserved exclusively for treating sick animals, ideally after testing to learn which antibiotics would be effective. However, in 2020, almost 100,000 tonnes of antibiotics were still used on farms around the world - a number that is expected to climb to 107,000 tons by 2030, rather than going down.

Is antibiotic use on farms banned anywhere?

In 2006, the UK banned four antibiotics that, at the time, were frequently being used to increase productivity.

While several countries, including the UK, have taken steps to stop this practice, many countries - including major producers like the US and China - still allow at least some antibiotics for growth promotion purposes.

Does the UK allow antibiotics in chicken?

While the UK has stopped the practice of using antibiotics solely for growth promotion, antibiotics are still given to chickens to prevent and treat disease.

Overall, British farmers have significantly cut the amount of antibiotics, resulting in 55% lower usage than in 2014. And yet, the UK is falling behind the EU when it comes to regulating on-farm antibiotic use. Whereas the EU has banned giving antibiotics to healthy animals as a preventative measure, the practice continues on British farms.

What does ‘antibiotic-free chicken’ mean?

In the UK, there are no rules pertaining to the use of the term “antibiotic-free chicken” on packaging. Without guidelines, the term means virtually nothing. For example, in the UK, none of the chicken on supermarket shelves contain antibiotics, due to pre-slaughter waiting periods, during which drugs leave the birds’ systems. On the flipside, the label also doesn’t mean that birds were raised antibiotic-free.

There is currently only one certification, offered by a NGO, that provides guidelines and limits for on farm antibiotic use. The Soil Association Organic certification discourages the routine use of antibiotics for disease prevention and requires that when animals do fall ill, homeopathic and herbal remedies be tried first. They strongly discourage the use of critically important antibiotics except when all other natural and synthetic medications have been unsuccessful.

The bottom line

The industrial farming of chickens necessitates the heavy use of antibiotics to prevent and treat diseases. That fact is driving antibiotic resistance, which experts view as a threat as big as a global pandemic. Not only that, but factory farms continue to be major hotbeds for the creation of bacteria and viruses like bird flu.

We need to change our broken food system. The biggest impact you can make as an individual is to leave animals off your plate. Check out our recipes and guides to a plant-based lifestyle.