Resources Antibiotics FAQ

Explore the questions below to learn about the basics of antibiotics, their use, and ways to protect them for the future.

Antibiotics are essential for combating animal disease. There is simply no other way to treat a bacterial infection.

These medicines are among the most valuable parts of a veterinarian’s kit and directly support animal health and welfare. 

Antibiotics treat painful illness in animals and stop disease outbreaks from spreading. This means healthier animals which can provide safer milk, meat and eggs.

But, in a world facing growing challenges like food security, emerging disease and antibiotic resistance, it’s important to understand the role of antibiotics and how we can best use them.

What are antibiotics?

Antibiotics are medicines that treat or stop the spread of an illness caused by bacteria.

Antibiotics are the only type of antimicrobial medicine  that are effective at fighting bacterial infections. They cannot combat other organisms such as a virus (this is why they should not be prescribed for people with the flu).

Antibiotics can take different forms, but the most common are a tablet or injection. The medicine works by attacking the disease-causing bacteria, typically in a few ways: 

  • The antibiotic prevents bacteria from multiplying and the disease dies off;
  • The antibiotic attacks the bacteria and prevents it from repairing itself; or
  • The antibiotic destroys the cell wall of the bacteria, which is essential to survival.

No matter the method though, the bottom line is that an antibiotic treatment stops the growth of a bacterial infection so the host (i.e. the animal) can eliminate it. The animal can then recover and return to health.

There are several types of types or ‘classes’ of antibiotics. Some are effective against a broad range of bacteria, while others may target only a narrow set of bacteria.

In addition, certain antibiotics can be used in both people and animals, while some are used in only one or the other.

All newer antibiotic classes that can treat people are solely reserved for use in humans, even if they are also effective in animals. This creates a limited toolkit of antibiotics available to treat a bacterial infection in an animal, which makes responsible use essential.

Is it safe to use antibiotics in livestock and pets?

Yes. Just like human medicines, animal medicines go through a rigorous, independent safety review before ever reaching our livestock or pets.

The average animal medicine takes around 8-10 years to reach the market. Throughout this process, safety and effectiveness are top priorities.

When developing an antibiotic, researchers conduct in-depth laboratory and field trial testing. They must ensure that the antibiotic effectively treats a bacterial infection without causing dangerous side effects.

The team will then confirm the antibiotic is also safe for the person handling it, the environment, and consumers eating food from treated livestock (following set withdrawal period). They will also conduct an antimicrobial resistance ‘risk analysis.’

Once the research team is confident in the safety, quality and efficacy of an antibiotic, they must then demonstrate it to governments around the globe.

The team submits studies, data and research to specialized government bodies in each nation. For example, in the U.S., it is the FDA’s Center for Veterinary Medicine (CVM), while in the European Union it is the European Medicines Agency (EMA) or individual Member States.

These agencies will spend 1-2 years closely analyzing this information. They may question the research team, request additional data, and conduct deep reviews of their work. 

If the agency agrees that the medicine is safe, effective and meets quality standards, they will issue an ‘approval.’ 

The process does not end there though. Agencies and the company marketing the antibiotic will continue to monitor use to ensure continued safety and effectiveness.

Why are antibiotics used in animals?

Animals get sick just like people do; antibiotics help treat the illness and can stop it from spreading to other animals.

Animals are vulnerable to some of the same bacterial infections as people, such as pneumonia and skin infections, and can be treated with antibiotics. These medicines not only treat the disease but also the animal: reducing the length of sickness reduces the animal’s suffering and contributes to their ongoing welfare and wellbeing.

Livestock producers, including the one billion smallholders, lose countless animals each year to disease. The ability to keep animals healthy is what allows them to provide for their family. 

For a developing world farmer, livestock are a form of savings and investment. Losing a single animal can put their entire livelihood, as well as food security, in jeopardy. 

Meanwhile, using antibiotics to clear up infections helps ensure the meat, milk, eggs and fish in our food supply is safe and free of harmful bacteria. ‘Withdrawal Periods’ guard against harmful trace amounts or ‘antibiotic residues’ in these foods.

Sustainable Agriculture Through Responsible Use

Not only is the global population growing, but more and more people are joining the middle classes. By 2030, two in three people worldwide will be considered middle-class, and this will drive an increased demand for milk, meat, eggs and fish. 

Even if per-person consumption falls, this incredible growth means more production is necessary. 

To meet this demand with limited natural resources, we must produce more food while reducing the burden on land, water and feed. It’s a delicate balancing act, which healthier animals can help achieve.

Antibiotics, alongside practices like vaccination, biosecurity, husbandry and nutrition, help keep animals protected from serious illness.

When animals are free of illness, they digest feed and process water more easily, which ultimately means they need less of both.

Healthy animals are also more productive, which means more and better-quality meat, milk and eggs per animal.

What’s more, radically slashing antibiotic use – such as in a ‘Raised Without Antibiotics’ system — can have a negative impact on animal welfare, according to the American Veterinary Medical Association (AVMA).

Abandoning the use of antibiotics in the U.S. could also mean more than 680 million additional broiler chickens would need to be raised annually to meet demand. Such an increase would also bring added environmental pressures, needing more than 1.9 billion extra gallons of water and more than 5.4 million additional tons of feed per year.

Ultimately, responsible antibiotic use can promote good animal welfare, health and sustainability, when used in combination with other tools like proper vaccination, biosecurity, good nutrition, rapid diagnostics and more.

How can antibiotics control disease outbreaks?

Using antibiotics in animals at risk of disease can stop a single case from becoming an outbreak.

Diagnosing disease in animals is a challenging job: like infants, livestock cannot describe their symptoms or let us know when they are coming down with an illness. Instead, veterinarians rely on other clues such as changes in behaviour or physical signs, reports of disease in the surrounding area, and the experience from previous outbreaks. But, an animal may be sick well before the symptoms are apparent.

So, when a veterinarian diagnoses an animal with a bacterial infection, they will treat them with an antibiotic as well as assessing the risk that the infection could spread to the other animals on the farm or beyond.

Using knowledge of how diseases spread, the veterinarian may find that other animals are at considerable risk and likely to become infected or may already be ill but not showing symptoms yet. When this is the case, they may recommend an antibiotics course to control the infection in the group of animals. 

Administering antibiotics to protect a herd or flock nips a disease threat in the bud rather than allowing it to take hold and cause the animal to suffer, only being diagnosed once symptoms become obvious or animals are lost.

Picture This….

Imagine being a veterinarian who comes across a sick pig on a farm: you discover it has a bacterial infection and prescribe a course of antibiotics. 

But you also know that the infection is contagious long before visible symptoms emerge. Therefore, you can assume that many other animals are already sick, even if they are not yet showing symptoms.

As the veterinarian, you have a choice: wait for the other animals to begin falling visibly ill or prescribe a course of antibiotics to control the disease and stop it from becoming a full-blown outbreak.

Every situation is different, but veterinarians must judge the risk to other animals of leaving them untreated in the face of an infectious disease. But if they know an animal is highly likely to already be sick, they know it is better, kinder and more cost-effective to nip that threat in the bud than to wait for an animal to visibly suffer.

Are antibiotics administered differently to animals than in people?

Sometimes. Treating animals, especially in large groups, presents unique challenges that we rarely ever face in human medicine.

Antibiotics for animals can be administered in the same way as for people: in a tablet or via an injection. 

But while a person can usually take responsibility for their medicine, animals must be treated by a person. And anyone with a pet knows that administering a medicine to an animal can be a challenge.

Larger animals or pets are often treated individually, but imagine the challenge of providing antibiotics to a group of pigs, chicken, or even fish. Veterinarians cannot simply communicate the risk of disease and ask the animals to patiently line up for a dose of life-saving medicine

When there is a disease threat in a large group, veterinarians must try to deliver what is called “group treatments”. Often, this means administering antibiotics through either feed or water to be sure the animals are receiving the treatment.

Using information about the farm, size of the animals, and feeding regime, the veterinarian can recommend the amount of medicated feed or water to provide to ensure a proper dosage.

While this method is not necessary with people, it can often be the best approach with large groups of animals, who cannot simply take a prescription to a pharmacy and start their course of treatment.

Can animals be raised without antibiotics?

Yes, but animal welfare may suffer. Farms that do not use or cannot access quality antibiotics often have higher rates of disease and animal death.

There are many contributing elements to disease prevention from good hygiene to nutrition and exercise but when bacterial disease strikes, there is no alternative to antibiotics. If an animal is sick and is not treated with the right medicine, the animal will suffer distressing symptoms or even death.

In some countries, some producers are shifting to ‘Raised Without Antibiotics’ or ‘No Antibiotics Ever’ systems. Consumers push for it because they believe these systems are better for animal welfare. 

However, farmers in a recent survey said “antibiotic-free” production systems were more harmful to animal welfare. 

Those with experience on “antibiotic-free” farms reported higher levels of disease and said, at times, maintaining “antibiotic-free” status was prioritized over animal health and welfare.

The American Veterinary Medical Association’s (AVMA) Chief Economist has also estimated that ‘raised without antibiotics’ chickens have a 25-50% higher mortality rate

When a bacterial infection strikes, it is simply not possible to care for an animal without antibiotics. We must focus on reducing the need for antibiotics through disease prevention and control.

‘Raised Without Antibiotics’ Systems and Animal Welfare

Shoppers in the US and elsewhere are increasingly seeing meat, milk and eggs in supermarkets labelled as “Raised Without Antibiotics” (RWA) or “No Antibiotics Ever” (NAE). This kind of certification has emerged in response to consumer demands.

In 2018, a research team evaluated whether antibiotic-free production systems upheld animal welfare. They surveyed more than 550 people directly involved in raising animals (over half in a RWA/NAE system) about the effects of such approaches.

The majority of those surveyed said these systems had negative impacts on animal health and welfare. They believed mortality and disease rates were higher compared to conventional programs.

Some even said that, in some cases, they believed operations prioritized their RWA/NAE label over the health and welfare of animals.

The results indicated that removing antibiotics from a farm does not remove disease; animals remain at-risk. Even more troubling is that marketing decisions could lead to animals not receiving the treatment they need to stop pain and suffering.

If animals are treated with antibiotics, then are antibiotics in our food?

Antibiotics in animals are strictly monitored to ensure no harmful ‘residues’ (i.e. trace amounts) are in our food. Strict ‘withdrawal periods’ ensure milk, meat and eggs are kept out of the food supply until an animal has sufficiently processed an antibiotic.

Food safety is a cornerstone of antibiotic development and regulation. Every antibiotic has a clear ‘withdrawal period’ – the number of days a livestock farmer must wait after an antibiotic treatment before that animal or its produce can enter the food supply.

This withdrawal period allows time for the animal to sufficiently processed the antibiotic. These are printed on the antibiotic label so users know how to meet their obligations. It ensures that milk, meat and eggs are free of harmful ‘residues,’ or trace amounts of a medicine.

Regulations surrounding withdrawal periods and ‘maximum residue limits’ are set and upheld internationally, and both are reviewed as part of a medicine’s approval process. Governments also conduct random tests on food coming from farms for harmful antibiotic residues to ensure that withdrawal periods are being respected. Penalties for violation can be steep.

What is antimicrobial resistance (AMR)?

Antimicrobial resistance (AMR) occurs when a disease-causing organism develops a tolerance to antimicrobials such as antibiotics, and can withstand their effects.

Most commonly, AMR refers to bacteria that are resistant to certain types of antibiotics. Resistance occurs because bacteria are hard-wired to survive. 

Bacteria will fight to outlast an antibiotic treatment, and, on occasion, some may be successful. These remaining bacteria can be more ‘resistant’ to the treatment in the future, which means a higher dosage or different antibiotic may be needed.

Ever since these first antibiotic treatments, we have faced resistant infections. Recent studies have found that certain resistant strains can be traced back thousands, even millions of years. It is a natural, evolutionary defence and an unavoidable challenge.

Antibiotics are so important in treating many common and serious diseases that antibiotic resistance is considered one of the biggest global health emergencies. If it is not properly managed, it could put commonly used antibiotics at risk and turn minor, treatable infections into major, lasting health threats.

Responsible antibiotic use can manage AMR though, and preserve these medicines for the future. For example, using vaccines to prevent a disease instead of using an antibiotic to treat it.

However, drug resistance is a threat to both people and animals, which is why strategies to contain it need a “One Health” focus. This means adopting approaches that unite doctors and veterinarians to tackle the problem in both areas at once.

Illegal Medicines and AMR

Like many sectors, veterinary medicine has a black market that deals in counterfeit or illegal products, and it is worth an estimated $2 billion every year.

But this growing market causes not only financial damage, it puts animals at risk, threatens farmers’ livelihoods and contributes to the risk of antibiotic resistance.

Legitimate medicine producers have strict requirements on the quality of drugs they produce. But counterfeiters do not – for them, quality doesn’t matter. They may produce or buy a legitimate antibiotic but then dilute it to create more, but weaker, doses. If this product is given to a sick animal, it simply doesn’t work. 

A diluted antibiotic will attack the infection but only with enough strength to kill the weakest bacteria. The rest of the bacteria will fight off the antibiotic and potentially develop a resistance to it.

When this happens, the animal is left infected with resistant bacteria thanks to this low-quality, illegal medicine, making it even harder to treat. Which means the veterinarian may have to use more powerful antibiotics that are saved for the most dangerous of infections.

Tracking and interrupting the flow of illegal veterinary medicines is an important step in tackling antibiotic resistance.

Does antibiotic use in animals lead to resistant bacteria in people?

The primary driver of antibiotic resistance in people is antibiotic use by people. But responsible antibiotic use in animals can help limit resistance.

Antibiotic resistance is a complex global health threat. Bacteria – resistant or not — can pass between humans and animals but, at present, scientists’ understanding of how this happens and the frequency is limited. 

It is understood that antibiotic use in animals plays a role in the development of resistance but according to the European Centre for Disease Prevention and Control, the “major cause of antibiotic resistance in humans remains the use of antibiotics in human medicine.” 

That is why other research shows that if action is only taken in animals, AMR in people will likely remain unchecked. 

The OECD also estimates that “three out of four deaths could be averted by spending just USD$2 per person a year on measures as simple as handwashing and more prudent prescription of antibiotics.”

More research is needed to fully understand the relationship between drug resistant bacteria in people and animals. However, until then, both sides must prioritise responsible use and actions with measurable results.

A key element of this is reducing the need for these medicines, rather than simply reducing their use. This means making the most of all the measures that help prevent disease in the first place, such as vaccination, good biosecurity and husbandry practices, and appropriate nutrition.

What drives resistance?

The misuse of antibiotics contributes to resistance by exposing bacteria to a greater volume of antibiotics, and according to European Centre for Disease Prevention and Control: “the major cause of antibiotic resistance in humans remains the use of antibiotics in human medicine.”

In the UK, recent research found that antibiotics were prescribed inappropriately for conditions such as sore throats in at least one case out of every 10, while the U.S. Center for Disease Control (CDC) estimates that 1 out of 3 human antibiotic prescriptions are unnecessary. 

This may be why, of the 18 ‘Antibiotic Resistance Threats’ the CDC identified, only two have potential origins in animals, or why the OECD found ‘simple steps’ in human health like hand washing could avert 3 out of 4 deaths from resistant bacteria each year.

But, the misuse or overuse of animal antibiotics can also contribute to resistance in animals, and there are clear steps we can take. 

We must focus on getting better at preventing disease and earlier, accurate diagnosis. This means improved nutrition, strong biosecurity, regular vaccinations, and more. It also requires equipping veterinarians so they may diagnose illness faster and treat more accurately.

While it is important we take steps in animal agriculture, we cannot lose the wider picture. Only addressing this health problem in livestock farming will not solve it. We need to better understand drug resistance and its relationship to human, animal and environmental health.

How can we reduce the need for antibiotics for animals?

By promoting disease prevention and good animal husbandry, we can reduce the need for antibiotic treatments.

Vaccinated animals that are fed a nutritious diet on a farm with strong biosecurity and regular veterinarian visits are simply less likely to need an antibiotic. 

Why? Each step reduces the risk of the animal falling ill with a bacterial infection. 

Vaccines prevent disease while good nutrition bolsters an animal’s immune system. Biosecurity measures, such as raising animals indoors, help stop bacteria from entering the farm. 

Regular veterinarian visits ensure animal health is closely monitored by an expert, while tools like immunostimulants and improved genetics offer new ways to strengthen the animals natural defences.

If an animal does fall sick, digital technologies like wearable sensors and A.I.-powered monitoring help a veterinarian catch it even earlier. Changes in a cow’s cough, which may be imperceptible to our ear, can now be the first indication of something serious.

Increasingly accurate diagnostic tools can then help veterinarians find the most appropriate treatment, which may not always be an antibiotic.

To avoid negative impacts to animal welfare, we cannot simply stop using antibiotics when animals need them. But we can try to reduce the need by reducing disease risk.

Reducing Antibiotic Use vs. Reducing the Need for Antibiotics

“Reducing antibiotic use” has become a popular mantra for tackling the growing problem of antibiotic resistance, but by itself, this solution is too simplistic. It overlooks an essential part of the conversation: animal welfare.

We could reduce antibiotic use tomorrow if we simply banned these medicines but animals – and people – would still get sick. 

Simple bans and restrictions on antibiotics would leave animals to suffer from bacterial disease while veterinarians would be left on the sidelines to do nothing. It ignores an animal’s right to treatment.

 Reducing the need for antibiotics, though, tackles the same problem but without creating additional challenges. It starts from a more responsible perspective: preventing the need for antibiotics in the first place.

What are the alternatives to using antibiotics in animals?

When an animal falls ill with a bacterial infection, there is currently no alternative to antibiotics.

The only alternative to antibiotics is prevention of disease. 

Constant innovation in the animal health sector means there is a wide range of existing and emerging products that help keep animals in good health. These include:

  • Vaccines: Researchers are working on a number of new vaccines to help protect animals from diseases. Some of these must be heat-tolerant to survive in tropical countries while others are working on multi-species vaccines.
  • Nutritional products: Feed can be supplemented with products that boost the immune system of livestock, making them less susceptible to disease in the first place. Researchers have been working on feed that builds up antibodies that can be passed on to offspring.
  • Parasiticides: Parasites survive by feeding on animals and can pass on disease or make an animal more susceptible to other infections. However, targeted medicines can control parasites before these organisms cause serious harm.

Precision farming tools like wearable sensors, A.I.-powered video monitoring, and more make it possible to immediately detect the first signs of illness. Some can even capture indications that are not visible to the human eye.

Veterinarians can then use increasingly accurate diagnostics – from big data applications to molecular diagnostics – to treat the disease quickly and effectively.

When disease is tackled early, veterinarians can use less aggressive treatments that save stronger, more powerful antibiotics for another day.

Using Vaccines to Reduce the Need for Antibiotics

Furunculosis is a devastating bacterial disease for fish. The disease causes wounds on the skin, bleeding and often death. It affects numerous species around the world, both in cold water and fresh water.

For years, it was one of the most common health problems facing fish farmers in Norway. One infected fish could spread the disease to countless others. Within days, an entire fish farm could be at risk of total loss if left untreated.

Fish farmers and veterinarians tried to take clear preventative measures, establishing restrictions in hatcheries and monitoring for the first sign of disease. But, as with all bacterial disease, furunculosis could not always be prevented. 

Antibiotics were used to treat infected fish and prevent the disease from spreading throughout the entire farm. 

The Norwegian Veterinary Institute in partnership with private sector stepped in and spent years developing an effective, safe vaccine. The results were transformative. As use of the vaccine spread, incidence of the disease plummeted amongst farmed Norwegian salmon.

This effective, sustainable solution was made possible through a focus on disease prevention, which reduced the need for antibiotics. 

Simply reducing antibiotic use was not an option; fish would still have been at high risk and mortality would have sky-rocketed. They needed to reduce the cause for antibiotic use by stopping the disease before it could strike. 

Today, the majority of Norwegian salmon is now vaccinated and free from furunculosis.

How can we encourage more responsible use of antibiotics?

Producers need access to affordable and comprehensive veterinary services, products and training along with greater trust and confidence in veterinary science.

Veterinarians are the best stewards of antibiotics. They are trained in their use and understand how to responsibly administer them. The animal medicines industry strongly recommends that antibiotics be used under veterinary supervision.

However, this is only possible when that supervision is available. Rural, remote and developing areas simply do not have enough veterinary professionals to guide responsible antibiotic use on the farm. 

While new services like tele-medicine and para-professionals are filling the gap, it is not enough. Improved access to proper, registered veterinary services is the foundation of responsible use.

Farmers and veterinarians also need access to the full range of animal health products that can stave off disease before antibiotics are even needed. This includes improved feed, diagnostics and custom treatments.

Farmers also benefit from training in the early signs of disease so their animals can be treated early and efficiently, and in following the appropriate treatment protocols.

But ultimately, it comes down to trust and confidence. Producers and farmers need to be confident in the veterinary support they receive so they do not resort to illegal or counterfeit veterinary medicines.

Our Commitment to Responsible Use

In 2017, HealthforAnimals released our “Antibiotic Commitment.” It outlines our five guiding principles for responsibly using antibiotics and tackling antimicrobial resistance.

The Commitment is supported by organizations representing more than 200 companies and 700,000 veterinarians worldwide. It outlines how we must promote greater veterinary supervision in antibiotic use, which includes increasing veterinary access in many countries. These trained professionals can ensure these medicines are used “as little as possible, as much as necessary”.

Signatories also committed to investing billions in new medicines that reduce reliance on antibiotics, like vaccines, diagnostics and immune boosters. These products can improve prevention and help reduce the need for antibiotics by stopping disease before it strikes.

The Commitment outlines a clear philosophy in the fight against antibiotic resistance. It is a problem that cuts across human health, animal health and the environment, and which can only be solved by a joint “One Health” effort.

But a Commitment is only as effective as the work behind it. This is why the Commitment is supported by its “Principles in Action” showing key programs signatories have undertaken that support each principle. 

Responsible use of antibiotics must be a cornerstone of animal care. Antibiotics can treat disease and improve the welfare of animals but to be effective, they must be used appropriately.