​​Owners - Antimicrobial Resistance Education​ 

 

  

 

Key Points  

In horses and people antibiotic resistant infections can cause a more severe infection because treatment options can be limited. This leads to longer and more complex treatments, higher costs and poorer outcomes. 

Topical therapies like Manuka honey and MicroSilver are effective alternatives to antibiotics when treating resistant or non-resistant bacterial infections of the skin or infected wounds. These medications also improve wound healing.  

Using less antibiotics and using antibiotics only when absolutely necessary will preserve antibiotics for use in people and animals that have no other options.  

Horse owners and managers should develop a close trusted relationship with their veterinarian. The decision to use antibiotics should be made in conjunction with your veterinarian.  

Having antibiotics in your barn to be administered to horses for any wound or skin infection is not using antibiotics responsibly.  

 

What is antimicrobial resistance?  

An antimicrobial is a general term used for substances that can kill or stop the growth of microbes, this includes antibiotics, antifungals, antivirals, etc. The main focus of this article will be on antibiotics, which are a drug that can kill or constrain the growth of bacteria.  

Antibiotic resistance does not mean the body becomes resistant to an antibiotics. It happens when the bacteria that caused an infection changes to become resistant to the antibiotic that was once effective to kill it. The end game is that the antibiotic stops working.  

Antibiotics used in horses are in general the same or a similar class of drugs as antibiotics used in human medicine, even though the majority of antibiotics are specifically labeled as veterinary products. This means that bacteria that becomes resistant to an antibiotic drug (veterinary or human) can share that resistance with other bacteria that infect people, or some bacteria can infect humans and horses equally.  

Companion animals, including horses, live in close contact with humans and share a common environment (like a barn). Therefore it is important for owners to understand that there is a very close and complex “cross pollination” between human and horses, and this includes the potential to share antibiotic resistant bacteria. This could have an impact in treating infections in people.   

 

Why everyone needs to take it seriously.  

 

Antibiotics are a vital finite resource and have been described as one of the most significant achievements of modern science. Antibiotics have contributed to decreasing the burden of common infections in people, animals and even plants. Furthermore, antibiotics have allowed modern medicine to develop and perform medical procedures like complex surgery or chemotherapy, in people and horses. Losing the efficacy of antibiotics due to the rise in resistant bacteria, could make these procedures difficult to impossible to perform. Furthermore resistant infections in horses can compromise animal welfare, by prolonging suffering and sometimes the need for euthanasia. 

Microbes that become resistant to one or many antibiotics are a major issue in veterinary and human medicine, putting at risk the efficacy of life-saving antibiotics globally. Thus compromising the health and welfare of horses.  

Antibiotic resistance is a leading cause of disease and death for people and animals worldwide. A 2019 study showed that during that year, antimicrobial resistant infections caused 1.27 million deaths and were associated with 4.95 million deaths in people around the world. In the US more than 2.8 million people per year are affected by antibiotic resistant infections. 1 In human hospitals in the US an estimated 622,390 cases among hospitalized patients annually are infected with a very resistant bacteria and 35,000 people die as a result of multidrug resistant bacterial infections per year.1,2 

It is estimated that if we do not all work together and do our part, antibiotic resistance could have devastating consequences around the world. A study suggested that it could cause 10 million deaths and accumulated costs to the global economy of $100 trillion by 2050.3 Antibiotic resistance has been called the next pandemic! 

Antibiotics are commonly used in the horse industry and its use has not being restricted by regulations in the US.4 However in June 2023, all medically important antibiotics will require veterinary oversight to be used in horses and other animals. Antibiotics like penicillin and oxytetracycline, which owners could purchase over the counter will require a veterinary prescription. 5 

A survey conducted by the United States Department of Agriculture Animal and Plant Health Inspection Service (USDA APHIS) for horse owners, indicated that 39.9% of equine operations had treated at least one horse (6 months or older) with antibiotics in the past 12 months, and 10.1 % of horses had been treated with an antibiotic in the previous 12 months.4 For horses 1 to 5 years of age, antibiotics were prescribed to treat an injury, wounds, or trauma in 5.1 % of them. In the 5 to 20 of years of age group, antibiotics were used for an injury, wounds, or trauma in 2.7 % of horses.6 Interestingly for horses of all ages, wounds were the top reason that owners reported antibiotic treatment in this survey. Likely indicating a potential way for improving the unnecessary use of antibiotics with the use of topical therapies when possible.   

Cephalosporin antibiotic is a medically important antibiotic that is commonly used in human and veterinary medicine.  Horse owners would be familiar with ceftiofur, a potent 3rd generation cephalosporin commonly prescribed for the treatment and prevention of common disorders in horses.4 The World Health Organization has placed this antibiotic into the highest priority category list of Critically Important Antimicrobials for Human Medicine. 4 Which means that this antibiotic must be reserved for patients where no other possible treatments exists and should not be the first drug that veterinarians and owners think of when treating a horse with a bacterial infection. Today more and more reports are documenting the increased resistance of bacteria to this, once very effective antibiotic.4 Therefore reducing the use of antibiotics and using it only when necessary, are key measures in attempting to slow the development of resistant bacteria. Furthermore cephalosporin including ceftiofur is not very effective against Staphylococcus, a common source of skin infections.4  

It was shown that equine veterinarians overprescribe antibiotics for illness that do not require them like asthma, viral respiratory infections or uncomplicated wounds.4 Several of the reasons for over prescription are prior success using antibiotic treatment or pressure from the owner to treat due to financial or time constrains. Sometimes the veterinarian cannot do further diagnostics or following up on the case can be challenging, so prescribing antibiotics can be felt like the “safe” thing to do. It is important that the equine community understands this problem and works closely with the veterinarian to design a treatment course that is best for the horse. Importantly horse owners must resist the urge to push antibiotics to be used when not need. Sometimes alternative therapies and waiting under a watchful eye can cure, sparing antibiotics and saving money! Client and veterinarian re-education leads to a cultural and behavioral change that is fundamental for changing the way antibiotics are used in equine practice.  

 

How does it happen? 

Bacteria can change to become resistant to antibiotics in a number of ways. 

Some antibiotics are a product of living organisms, for example penicillin is made by a fungus. Therefore bacteria can be exposed to some of these substances in nature, and bacteria could develop resistance naturally. Scientists have found ancient bacteria that was naturally resistant to antibiotics, even though they were never exposed to the actual antibiotic drug. This is part of the normal push and pull observed throughout the natural world. Bacteria can evolve very fast and adapt to be stronger and survive adverse conditions, including antibiotics.  

But the way antibiotics are used and overused in humans and animals, can accelerate the emergence of bacterial resistance. For example having a bottle of penicillin in your barn to administer to a horse with a superficial wound would be considered incorrect use of antibiotics.  

More importantly taking antibiotics unnecessarily can help bacteria to evolve to become resistant to antibiotics faster. This is why it’s important not to take antibiotics unless they’re prescribed, and only use them for the infection they’re prescribed for.  

Not only antibiotics that are taken by mouth or injection induce bacteria resistance. Antibiotics applied on the skin for any little scratch or wound can also cause the bacteria that is on the skin to develop antibiotic resistance. For this reason applying triple antibiotic ointments freely on people and horses should be strongly discouraged. Additionally giving horses antibiotics by mouth or injection can have serious side effects like killing the good gut microbes and causing life threatening diarrhea.  

  

The picture graphically represents a way by which bacteria resistant to an antibiotic could overgrow after an antibiotic is used. These bacteria that are resistant can also transfer their resistance information to other bacteria, making them resistant to that antibiotic as well.  

 

Where is this happening? 

Yes, antibiotic resistance is happening in your barn and farm!  

Today with the ease of travelling, microbes can also move across the globe traveling with people and horses. Remember horses are the most traveled animal after, yes people!  

As humankind recently experienced with the spread of the virus that caused the COVID-19 pandemic, this is also true for antibiotic resistant bacteria. So globalization has helped “bad bugs” spread fast and widely.  

Antibiotic resistance is a worldwide problem affecting people, animals, plants and the environment. Despite this many people, including many within the equine community, are not aware of this growing issue and its consequences. Education of horse owners to raise awareness and improve antibiotic used is paramount to manage the antibiotic resistance crisis.  

 

Today it is easy for people, animals and goods to travel around the world, similarly bacteria that are resistant to antibiotics can also travel from one place to another.  

 

Role of horse owners in safeguarding antibiotics 

There is a general lack of awareness by horse owners regarding the concerns of antibiotic resistance. This is similar to human medicine where the general public has a superficial understanding of bacterial resistance and its negative consequences to health.  

W.F. Young believes that this needs to change and the company is playing a role by getting involved by working with scientists and veterinarians to find natural healing solutions that are antibiotic-free. Everyone everywhere has a role to play in using antibiotics only when no other options are available.   

It all starts at home. You, as a horse owner or farm manager, have a critical role to play in safeguarding antibiotics and using them only when prescribed by a veterinarian and when absolutely necessary. To combat antimicrobial resistance, the effective use of antibiotics depends on the owners or managers and their collaboration with a prescribing veterinarian. As with pet owners, horse owners mediate the treatment of their animals, and can control antibiotic usage and other actions that can influence the appearance of antibiotic resistance in their horses.7 Open candid communication during the veterinary consult between the client and the veterinary care team is paramount to discuss alternatives to antibiotics and reduce over prescription of antibiotics.7 

 

Developing a trusted relationship with your veterinary and having open communication is fundamental for a two way education about improving antibiotic use.  

 

Veterinarian - owner partnership to improve antibiotic use 

Communicating with your trusted veterinary care team about options to treat your horse and when an antibiotic is needed or non-antibiotic options can be used, is a key role you can have to contribute with the fight against antibiotic resistance.  

Remember not all illnesses or wounds need to be treated with an antibiotics, sometimes the body can heal on its own with time and supportive care or using alternatives to antibiotics. As an example most uncomplicated colds in people and horses do not need antibiotics because are normally caused by viruses and antibiotics have no effect on viruses. Similarly not every wound needs to be treated with an antibiotic, but wounds especially on the lower limbs must always be assessed by a veterinarian to evaluate the potential involvement of joints or tendons. The liberal use of triple antibiotic ointments for any wound should be avoided, since these ointments are antibiotics and can cause the appearance of resistant bacteria on the skin.  

Even large wounds can be successfully managed with natural products containing Manuka honey and MicroSilver®, as seen on the pictures below.  A common complication responsible for delayed wound healing in horses is infection. 8 Therefore the use of natural products with antimicrobial properties like Manuka honey and MicroSilver® will prevent or cure infection and in this way improve wound healing. In a group of horses where experimentally surgical wounds on the distal limbs were made, it was shown that topical application of Manuka Honey improved healing. 9 In another clinical study applying Manuka honey in the wound, improved healing, decreased infection and increased veterinarian satisfaction. 10 Furthermore many of the products commonly applied to equine wounds are effective in killing bacteria, but they are also toxic to new growing tissue cells that are repairing the wound, delaying healing. Manuka honey does not cause tissue damage and stimulates healing, decreasing the duration of wound healing.11 Studies have shown that human patients treated with honey had a significantly lower average duration of wound healing compared with those treated with Silver Sulfadiazine (SSD).11 This is likely similar for horses were SSD is used in some settings, which should be discouraged as it impairs wound healing. It is known that the acidic pH of honey creates acidification of the wound which in turn improves healing by increasing the local oxygen concentration. 12 The high sugar content of Manuka honey improves wound healing because the osmotic effect draws water from the wound bed, creating an outflow of lymph which positively impacts healing. 12 Manuka Honey also contains antioxidants, flavonoids, phenolic acids and other enzymes, which are important determinants of its local anti-inflammatory activity.11-13 Lastly, Manuka honey has been shown to have activities that increase the production of compounds on the wound leading to improve the growth of new blood vessels and the multiplication of cells that repair the wound.8,9 

The right formulation and concentration of silver, such as MicroSilver®, is able to kill bacteria in the wound and improve healing while not damaging the healing tissues.  

  

 

Applying Silver Honey® to wounds, abrasions and superficial skin infections instead of an antibiotic ointment is important to decrease the use of antibiotics and minimize the emergence of bacterial resistance. The pictures above showed the positive effect on preventing infection and helping healing of a large wound on a mare’s pectoral area when Silver Honey® spray gel was used. No antibiotics topical or systemic were used to treat this deep wound. The application of the spray gel made it possible prevent touching and potentially contaminating the wound. Furthermore the gel formulation adheres to the all the wound surfaces preventing infection and promoting healing.  

 

Prevention is KEY 

Simple measures like proper hand washing, is one of the best ways to stop infections, avoid getting sick, and prevent spreading germs. Always wash your hands after touching, feeding, or caring for your horse. Hand washing is very important when cleaning a wound or changing a bandage on your horses.  

 

The picture portrays the 5 moments of hand washing for equine veterinarians, this is adapted from human doctors. Horse owners can follow these recommendations as well since hand washing is an inexpensive and safe way to keep yourself and your horses safe.  

 

The infographic above from the Center for Disease Control and Prevention (CDC) highlights the importance of prevention and the part everyone can play to keep healthy. Antibiotics are not needed in healthy people so prevention is the key. These points can also be applied to caring for your horses. In a horse barn the addition of proper stall cleaning and disinfection is also a key point in prevention.  

 

Vaccinating animals and people is an important measure for preventing disease and lowering the need to use antibiotics. The tetanus vaccine in horses is paramount to prevent a devastating disease that could be acquired through wounds. Also vaccinating horses against respiratory viruses like flu, lowers the chances for them to get sick and decreases the need for antibiotics to be prescribed.  

 

 

 

Vaccines play a key part of preventive care for your horses. Keeping your horses up to date on vaccines lowers the need for antibiotics.  

  

Use of alternative therapies to antibiotics 

As every horse owner knows, wounds in horses, especially the ones affecting the lower portion of limbs, can be difficult to treat and have complications like the development of “proud flesh”. This protracted complex healing has a negative financial impact and worsens the horse’s outcome.8 Similar to what occurs in people, wound infections are normally responsible for delayed wound healing in horses.8 

Wounds, skin infections or abscesses could often be treated successfully without the need to use antibiotics. However what is commonly used by horse owners to treat wounds can sometimes be effective in killing bacteria but have a negative impact on the healing process, so making things worse! For example hydrogen peroxide, iodine solutions, silver sulfadiazine or silver sprays, are toxic to the growing skin cells that are trying to heal the wound. Furthermore applying human formulated triple antibiotic ointments is a common practice in some settings. These over the counter antibiotic ointment products, contain… you guessed it, antibiotics! These should not be used indiscriminately for every horse with a wound.   

Rather than antibiotic ointments or other topical remedies that can negatively affect the healing process, use safer, effective and equine formulated products like Silver Honey®.  

Similarly to what occurs with pet owners, horse owners could perceive topical therapy for the treatment of skin conditions in their horses as more difficult to apply which in turn could negatively affect compliance. This could put pressure on the veterinarian to prescribe an antibiotics. Remember to work with your veterinary team and ONLY use antibiotics when no other options are feasible. Also DO NOT reach for that open bottle of antibiotic in your barn and start giving it to an injured horse without first consulting with your veterinarian.  

There are many advantages for early and frequent use of topical therapies to treat superficial skin infections in pets, and this can be translated to horses as well. Some of the advantages are:14 

• Faster healing of the lesion  
• If the horse needs to be on antibiotics, combining it with topical treatment, could decreases the duration of oral or injectable antibiotic administration  
• Shampoos help to remove bacteria and yeast from the skin surface 
• Topical therapies are in general safer and have minimal adverse effects. However be careful to use products that would not impair healing 
• Microbial resistance to non-antibiotic topical therapies is very rare  

• Topical therapies can also help to restore the skin back to normal  

Veterinarians are gaining awareness of bacterial resistance affecting pets and horses with skin infections, current recommendations are to treat superficial skin infections with topical therapies. Furthermore the topical administration of safe remedies to treat wounds are advantageous over systemic antibiotic administration because of lower treatment costs, killing microbe effects at the affected site and avoiding complications of systemic antibiotic administration. 10 

 

In summary… 

Antibiotic resistant bacteria is a growing shared problem in veterinary and human medicine. The use of antibiotics “just in case” for the prevention of wound infections is an ethical concern and implies poor stewardship.10 Therefore, using alternative therapies like silver and honey, or combinations of both for the prevention and treatment of wound bacterial infections as well as improving healing, is a good alternative that will help us preserve antibiotics to be used only when needed.  

Using topical bactericidal products such as silver or honey, that aid with wound healing in lieu of systemic antibiotics will lead to decreased treatment costs, lower risk for secondary complication of systemic antibiotic such as colitis and improved treatment outcomes.  

Key points for horse owners to be good stewards of antibiotics:  

• Not all wounds or skin infections need to be treated with an antibiotic. 
• Only use antibiotics when prescribed by your veterinarian.  
• DO NOT pressure your veterinarian to prescribe antibiotics unnecessarily.  
• When prescribed by a veterinarian follow the directions for administration of the antibiotic.  
• Using antibiotics responsibly will help to prevent the emergence of bacterial resistance.  

• Use products such as honey, silver or a combination of both. These natural products are effective in killing bad bacteria, help with healing and do not promote bacterial resistance.   

References    

1. CDC. Antibiotic Resistance Threats in the United States. In. www.cdc.gov/DrugResistance/Biggest-Threats.html: US Centers for Disease Control and Prevention; 2019:1-148.
2. Jernigan JA, Hatfield KM, Wolford H, et al. Multidrug-Resistant Bacterial Infections in U.S. Hospitalized Patients, 2012-2017. The New England journal of medicine 2020;382:1309-1319.
3. Clift C. Review of Progress on Antimicrobial Resistance. In. https://reader.chathamhouse.org/review-progress-antimicrobial-resistance#: Chatham House, the Royal Institute of International Affairs; 2019:1 - 18.
4. Ryan CA, McNeal CD, Credille BC. Ceftiofur use and antimicrobial stewardship in the horse. Equine veterinary journal 2023.
5. Association AVM. Medically important antibiotics to move from OTC to Rx. In. https://www.avma.org/blog/medically-important-antibiotics-move-otc-rx: AVMA; 2022.
6. Equine 2015. Baseline Reference of Equine Health and Management in the United States, 2015. . In. Fort Collins CO: USDA–APHIS–VS–CEAH–NAHMS; 2016:1-190.
7. Smith M, King C, Davis M, et al. Pet owner and vet interactions: exploring the drivers of AMR. Antimicrobial resistance and infection control 2018;7:46.
8. Carnwath R, Graham EM, Reynolds K, et al. The antimicrobial activity of honey against common equine wound bacterial isolates. Veterinary journal 2014;199:110-114.
9. 9.  Bischofberger AS, Dart CM, Perkins NR, et al. The effect of short- and long-term treatment with manuka honey on second intention healing of contaminated and noncontaminated wounds on the distal aspect of the forelimbs in horses. Veterinary surgery : VS 2013;42:154-160.
10. Mandel HH, Sutton GA, Abu E, et al. Intralesional application of medical grade honey improves healing of surgically treated lacerations in horses. Equine veterinary journal 2019.
11. Gupta SS, Singh O, Bhagel PS, et al. Honey dressing versus silver sulfadiazene dressing for wound healing in burn patients: a retrospective study. Journal of cutaneous and aesthetic surgery 2011;4:183-187.
12. 12.  Molan P, Rhodes T. Honey: A Biologic Wound Dressing. Wounds : a compendium of clinical research and practice 2015;27:141-151.
13. 13.  Tsang KK, Kwong EW, Woo KY, et al. The Anti-Inflammatory and Antibacterial Action of Nanocrystalline Silver and Manuka Honey on the Molecular Alternation of Diabetic Foot Ulcer: A Comprehensive Literature Review. Evidence-based complementary and alternative medicine : eCAM 2015;2015:218283.
14. 14.  Hillier A, Lloyd DH, Weese JS, et al. Guidelines for the diagnosis and antimicrobial therapy of canine superficial bacterial folliculitis (Antimicrobial Guidelines Working Group of the International Society for Companion Animal Infectious Diseases). Veterinary dermatology 2014;25:163-e143.

Resources 

CDC. 2022. Antimicrobial Resistance - Protect yourself and Your Family https://www.cdc.gov/drugresistance/protect-yourself-family.html Accessed Jan 6 2023. 

AVMA. Antibiotic use is changing. Talk to your veterinarian. https://www.avma.org/resources/public-health/antibiotic-use-changing-talk-your-veterinarian 

FDA. GFI #263: Frequently Asked Questions for Farmers and Ranchers. 

https://www.fda.gov/animal-veterinary/antimicrobial-resistance/gfi-263-frequently-asked-questions-farmers-and-ranchers