Kars conjunctivitis study highlights MDR risk in cats and dogs
Bottom line
A new study from Kars, Türkiye examined conjunctival swabs from 59 cats and dogs with conjunctivitis and used culture plus MALDI-TOF mass spectrometry to identify the bacteria present. The researchers reported broad bacterial diversity and found that 86.49% of isolates met their definition of multidrug resistance, underscoring how often ocular infections may involve organisms that won’t respond predictably to empiric therapy. The paper adds to a small but growing body of veterinary ophthalmology literature using MALDI-TOF to sharpen organism identification in companion animals, and it reinforces that conjunctivitis cases in dogs and cats can involve both common opportunists and bacteria with zoonotic relevance. (ispecjournal.com)
Why it matters: For veterinarians, the practical takeaway is stewardship. Conjunctivitis is common, but the appearance of the eye alone often doesn’t identify the cause, and bacteria may be secondary rather than primary pathogens, especially in dogs. Current guidance from veterinary microbiology and ophthalmology sources notes that culture and susceptibility testing are most useful in severe, chronic, recurrent, outbreak-associated, or poorly responsive cases, while interpretation remains tricky because topical ocular breakpoints are limited or absent. That makes local surveillance data valuable, even when in vitro resistance doesn’t perfectly predict clinical response. (merckvetmanual.com)
What to watch: Expect more attention on ocular-specific antimicrobial stewardship, including better local antibiograms, clearer interpretation standards for topical therapy, and follow-up research separating primary pathogens from conjunctival flora. (pmc.ncbi.nlm.nih.gov)
Key facts
- Study location
- Kars, Türkiye
- Study sample
- Conjunctival swabs from 59 cats and dogs with conjunctivitis
- Methods
- Culture and MALDI-TOF mass spectrometry
- Study period
- 2024–2025
- Main finding
- 86.49% of isolates were classified as multidrug resistant
- Study takeaway
- Ocular infections in companion animals may not respond predictably to empiric therapy
- Diagnostic implication
- MALDI-TOF was used to sharpen organism identification in ophthalmic samples
- Clinical context
- Conjunctivitis cases in dogs and cats can involve common opportunists and bacteria with zoonotic relevance
A newly published study on conjunctivitis in cats and dogs from Kars, Türkiye points to a high burden of antimicrobial resistance in ocular bacterial isolates, with 86.49% classified as multidrug resistant in samples collected during 2024–2025. Using both conventional culture and MALDI-TOF MS, the authors analyzed conjunctival swabs from 59 clinical cases and highlighted substantial bacterial diversity alongside the resistance findings. For clinicians, the headline isn’t just the MDR rate, but the reminder that ocular infections in companion animals may be microbiologically more complex than they appear at first exam. (pmc.ncbi.nlm.nih.gov)
That matters because conjunctivitis is one of the more routine eye complaints seen in small animal practice, yet its causes are varied. Merck Veterinary Manual notes that conjunctivitis in dogs and cats can stem from infectious disease, environmental irritants, foreign bodies, tear film disorders, and conformational problems, and that the clinical appearance alone usually isn’t specific enough to identify the cause. In cats, viral and atypical infectious causes such as feline herpesvirus 1, Mycoplasma, and Chlamydia are especially relevant, while in dogs, bacteria are often opportunists rather than the primary driver. (merckvetmanual.com)
The Kars report also fits into an emerging trend in veterinary diagnostics: more use of MALDI-TOF MS to improve organism-level identification in ophthalmic samples. Earlier work in dogs and cats with conjunctivitis likewise found Gram-positive organisms, especially staphylococci, to be common ocular isolates, and identified zoonotically relevant species such as Staphylococcus felis and Streptococcus canis. In that earlier 25-case study, resistance was generally lower overall, though important pockets of resistance were still noted, including high imipenem and ampicillin resistance in Enterococcus spp. and extended-spectrum beta-lactam resistance among Enterobacteriaceae. The contrast suggests resistance patterns may vary substantially by population, geography, case mix, and study design. (ispecjournal.com)
Recent ophthalmology literature has been warning that antimicrobial resistance is becoming a larger issue in veterinary eye care, but also that susceptibility data have limits. A 2026 review in Veterinary Ophthalmology said AST in ophthalmology is difficult to interpret because most breakpoints are derived from systemic dosing, even though topical eye medications can achieve very different, often higher, local concentrations. The same review argued that stewardship will depend on stronger surveillance, better ocular-specific interpretive frameworks, and more deliberate use of culture data in practice. JAVMA guidance from the American College of Veterinary Microbiologists similarly recommends collaboration with diagnostic labs and notes that topical antimicrobial breakpoints do not currently exist for ocular infections. (pmc.ncbi.nlm.nih.gov)
Those caveats are important when reading a headline MDR percentage. A resistant result on paper doesn’t always mean a topical drug will fail clinically, and a cultured bacterium doesn’t always mean it’s the primary pathogen. Still, a high MDR signal is hard to ignore, particularly in referral, recurrent, shelter-associated, or treatment-refractory cases. It also raises One Health considerations, because some ocular isolates in companion animals can have zoonotic relevance, and ophthalmology settings have documented opportunities for bacterial cross-contamination if infection control slips. (frontiersin.org)
Why it matters: For veterinary professionals, the study strengthens the case for moving beyond reflex empiric treatment when conjunctivitis doesn’t follow the expected course. In straightforward first presentations, many clinicians will still treat empirically. But in chronic, severe, recurrent, or nonresponsive cases, this kind of resistance data supports earlier sampling, culture, and susceptibility testing, paired with a search for underlying causes such as herpesvirus, tear deficiency, eyelid disease, foreign material, or environmental irritation. It also supports tighter antimicrobial stewardship conversations with pet parents, especially when they expect an antibiotic drop to be the automatic answer. (merckvetmanual.com)
The study may also be useful as a regional surveillance signal. Even if its findings aren’t directly generalizable to every practice setting, they add to the evidence that local microbiology matters in ophthalmology, just as it does in dermatology, urinary disease, and respiratory infections. Practices with access to reference laboratories using MALDI-TOF or robust susceptibility panels may be better positioned to build internal treatment patterns over time and recognize when their empiric habits no longer match the organisms they are actually seeing. (pmc.ncbi.nlm.nih.gov)
What to watch: The next step is whether this paper is followed by fuller publication details, organism-level breakdowns, and comparative datasets from other regions, which would help clinicians judge how broadly the Kars resistance pattern applies and whether ocular-specific stewardship recommendations need to change. (pmc.ncbi.nlm.nih.gov)