If your dog or cat keeps getting skin infections that won’t fully clear up, antibiotic resistance in pet skin infections may be part of the problem. A new study tracked 11 years of skin culture results from companion animals and found that resistance to some commonly used antibiotics was substantial — and that this pattern held from 2013 all the way through 2024.
The practical takeaway: for recurrent or stubborn skin infections, a culture test — a lab test that identifies which bacteria are present and which drugs can actually kill them — may make a real difference in whether treatment works.
Why Skin Infections in Pets Can Be So Hard to Fully Resolve
Skin infections are among the most common reasons pet owners visit the vet. In dogs, a condition called pyoderma (a bacterial skin infection — “pyo” means pus, “derma” means skin) can keep coming back, causing itching, redness, hair loss, and sometimes painful sores. Cats get skin infections too, often from bite wounds or as a complication of underlying allergies.
The traditional approach has been to prescribe a broad-spectrum antibiotic — one that targets a wide range of bacteria — and hope it works. But bacteria can develop resistance to the drugs meant to kill them. When the specific bacteria causing your pet’s infection happen to be resistant to the prescribed antibiotic, the treatment may fail, and you’re back at the vet’s office facing the same problem again.
What Researchers Looked At
Researchers analyzed skin culture records collected at a companion animal hospital laboratory in north-western Italy over 11 years, from 2013 through 2024. The dataset included:
- 447 antimicrobial-susceptibility tests — lab tests that check whether specific bacteria can be killed by specific drugs
- 391 positive cultures — lab samples that confirmed bacterial growth
An antimicrobial-susceptibility test works like this: the lab grows the bacteria from your pet’s skin swab, then exposes them to a panel of antibiotics to see which ones stop growth. The results show the vet which drugs are likely to work and which ones the bacteria are already resistant to. Think of it like a targeted matchmaking process — pairing the right drug to the specific bug.
The Same Bacterial Families Kept Appearing Year After Year
Three groups of bacteria dominated the culture results across the full 11-year period:
- Staphylococcaceae — a family that includes staph bacteria, a major cause of bacterial skin infections in dogs and cats
- Enterobacteriaceae — a group that includes bacteria like E. coli, more often found in deeper or more complicated infections
- Pseudomonadaceae — includes Pseudomonas, a type of bacteria known for being especially hard to treat
These aren’t unusual organisms. They’re the routine suspects in pet skin infections, and their consistent presence over more than a decade suggests this is a stable, predictable pattern.
Resistance to Common Antibiotics Remained Substantial
The more notable finding was about resistance. Some of the antibiotics typically used as first-line treatments — meaning the drugs vets commonly reach for first — showed substantial resistance across the study period. A notable portion of the bacteria collected from sick animals were already resistant to some of the most commonly prescribed options.
The study didn’t report a single resistance percentage across all drugs, since resistance varied by antibiotic and bacterial type. But the consistent message across 11 years was clear: prescribing without testing is a gamble.
What This Means for Your Pet’s Skin Care
This research adds to a growing body of evidence that “test first, treat second” is the smarter approach — especially when skin infections keep coming back or don’t fully clear up with standard treatment.
Here’s what culture-guided treatment looks like in practice:
- Your vet swabs the infected area and sends the sample to a lab.
- The lab grows the bacteria and tests which antibiotics can stop them.
- Your vet prescribes the drug most likely to work for this specific infection — not just the most commonly used option.
The process takes a few extra days, since the lab needs time to grow the bacteria. But for recurrent or deep infections, that brief wait can prevent weeks of ineffective treatment.
The study also raised a broader concern. Some antibiotics used in pets are considered critically important for treating serious infections in people. If these drugs are overused in animals and resistance spreads, it could make them less effective in human medicine too. Responsible use — prescribing only when necessary, and only after confirming which drug is truly needed — matters beyond your individual pet.
When to Bring Up Culture Testing With Your Vet
The study specifically noted that recurrent or deep skin infections are the cases where culture testing is most appropriate. Ask your vet about a culture test if:
- Your pet has had the same skin infection more than once
- The infection doesn’t clearly improve after a full course of antibiotics
- The infection is deep, severe, or spreading
- Your pet is on medications that affect the immune system
Your vet may already be planning to run one — especially for complicated cases — but it’s always okay to ask.
Limits of This Research
Like all retrospective studies — ones that look back at existing records rather than run a controlled experiment — this research has limits. The data came from a single hospital laboratory in north-western Italy, so the resistance patterns found here may not perfectly reflect every veterinary practice or every region. Resistance rates in other countries or geographic areas may differ, and these findings should be interpreted with that context in mind. The study also reviewed lab records rather than tracking individual patient outcomes, so it can’t tell us how specific treatment decisions affected recovery. Larger, multi-site studies would help confirm whether these patterns hold more broadly.
Bottom Line
Eleven years of skin culture data from dogs and cats paint a consistent picture: antibiotic resistance in pet skin infections is real, it’s present in common bacteria, and it hasn’t gone away on its own. For pet owners dealing with persistent or recurring skin problems, asking your vet about culture testing before or alongside antibiotic treatment may lead to faster, more effective results — and help preserve important antibiotics for when they’re truly needed.
This article summarizes peer-reviewed research for educational purposes. Always consult with your veterinarian for personalized advice about your pet’s health and behavior.