Increased antibiotic resistance threatens the eyesight of horses and human health
Researchers have warned that, with the growing threat of antibiotic resistance, the eyesight of horses and other animals is at risk; preventing eye problems plays a key role.
A veterinary review published in Veterinary Ophthalmology shows that antibiotic-resistant eye infections that can damage vision are “becoming a serious threat to vision in dogs, cats and horses.”
The study, conducted by Lionel Sebbag and Oren Pe'er of the Koret School of Veterinary Medicine at Hebrew University of Jerusalem, aimed to examine antibiotic resistance in veterinary ophthalmology and placed particular focus on bacterial corneal infections; infections that can threaten vision within hours.
The research team calls for earlier diagnosis, more targeted use of antibiotics, stronger infection-control measures, and strategies to preserve the effectiveness of antibiotics for future patients.
The authors write: “Antimicrobial resistance is no longer a theoretical concern in veterinary ophthalmology.
“This phenomenon is a clinical reality and an evolving one.
” Drs Sebbag and Pe'er told H&H that horse owners may often think of antibiotic resistance as a problem in human medicine.
“But this is increasingly becoming an equine issue as well,” they said.
“Every responsible decision about antibiotics today helps preserve these life-saving treatments for horses that will need them tomorrow.
For a horse, losing vision can fundamentally change its life; therefore, preserving the effectiveness of antibiotics is not just about combating resistance, but about protecting vision, welfare, performance and quality of life.
” Bacterial keratitis, a serious corneal infection, is among the most urgent emergencies in veterinary eye care.
Antibiotics remain the “cornerstone of treatment” for this disease, but researchers found that “there is growing evidence that many of the bacteria causing these infections are increasingly becoming resistant to common drugs”.
By reviewing studies conducted in different parts of the world, researchers identified Staphylococcus pseudintermedius, Beta-hemolytic streptococci and Pseudomonas aeruginosa as the most common bacterial agents isolated in companion animals.
Antibiotic resistance: common strains The authors said: “What is particularly concerning is the increasing prevalence of multidrug-resistant strains, especially in referral and speciality care settings, where the most severe cases are concentrated.
“One of the most consistent findings across studies was the impact of prior antibiotic use.
Animals that had recently received topical antimicrobial treatment were more likely to harbor resistant bacteria and less likely to yield a positive culture result; a matter that makes accurate diagnosis and targeted treatment more difficult.
“This review also highlights a striking gap between laboratory tests and real-world clinical outcomes.
Standard antimicrobial susceptibility tests are largely based on the assumption of how antibiotics work when given systemically, but eye drops reach entirely different drug concentrations at the eye.”
As a result, laboratory susceptibility reports cannot always accurately predict whether a treatment will succeed or fail in clinical practice.
The researchers said laboratory results should always be considered alongside the veterinarian’s clinical observations, the severity of the disease, and the patient’s history.
They added that, where possible, taking microbiological samples is very important to help guide treatment decisions.
The researchers said: “Beyond the immediate clinical outcomes, this review places antibiotic-resistant eye infections in the broader one-health context.
” They said: “Some bacterial species commonly seen in eye infections in animals have recognized zoonotic potential and can be transmitted between animals and humans.
The authors note that veterinary clinics, equipment, and even homes can be environments in which resistant organisms circulate; an issue that highlights the importance of strict hygiene and infection control.
” This review recommends treatments that do not use antibiotics, such as antiseptic and ultraviolet-based treatments.
Preserving vital medicines The authors said: “The aim is not only to resolve the current infection, but also to preserve treatment reliability for future patients.
” H&H vet Karen Coumbe said horses are particularly prone to eye diseases because their large eyes are exposed to dust, dirt, and irritation from flies, especially in summer.
She said: “Antibiotics should not be the first line of treatment for every painful eye, although some see them as a quick fix.
” She added: “The veterinarian should examine the horse before prescribing antibiotic medication, including eye ointment and drops.
“However, somewhat paradoxically, some antibiotic eye ointments are still available over the counter without veterinary involvement.
She said: “Although I do not recommend using eye antibiotics without a prescription, it is still common and in some cases can certainly create more serious problems.
Eye diseases should be taken seriously, and other options should be considered rather than starting antibiotics immediately.
“Prevention is just as important; simple measures such as fly masks and avoiding haynets that allow debris to fall into the eyes help reduce the risk of disease.
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