Study explores herbal red palm oil shampoo for pet skin infections
Bottom line
Researchers in Thailand reported an in vitro proof-of-concept study for a pet shampoo formulated with red palm oil and extracts of Rhinacanthus nasutus, Curcuma longa, Zingiber montanum, and Zingiber officinale. The work, published as a preprint tied to Veterinary Sciences, found that the plant extracts showed antibacterial, antifungal, antioxidant, and anti-inflammatory activity in lab testing, and the final dog and cat shampoo formulations retained measurable activity after formulation. The authors reported antibacterial inhibition of 92.4% for the dog shampoo and 90.8% for the cat shampoo, with antifungal inhibition of 88.6% and 87.3%, respectively. Importantly, the study was entirely in vitro and did not include live-animal testing or clinical cases. (preprints.org)
Why it matters: For veterinary professionals, the study lands in a familiar clinical space: skin infections are common, topical therapy is increasingly important, and antimicrobial stewardship is pushing the field to reduce unnecessary systemic antibiotic use. Current guidance from ISCAID says topical antimicrobial therapy alone is the treatment of choice for surface and superficial pyoderma, while Merck notes medicated shampoos remain a core part of topical dermatology care. This paper adds early-stage evidence for a plant-based candidate, but it doesn't yet show safety, efficacy, contact-time performance, or real-world outcomes in dogs or cats, so it's better viewed as formulation research than a practice-ready product. (pmc.ncbi.nlm.nih.gov)
What to watch: The next step is whether the formulation advances into irritation testing, stability work, and controlled clinical trials in dogs and cats with pyoderma, Malassezia dermatitis, or dermatophytosis, as the authors themselves recommend. (preprints.org)
Key facts
- Study type
- In vitro proof-of-concept study
- Product
- Pet shampoo
- Formulation
- Red palm oil plus extracts of Rhinacanthus nasutus, Curcuma longa, Zingiber montanum, and Zingiber officinale
- Species-specific formulations
- Dog shampoo and cat shampoo
- Main finding
- Finished shampoos retained measurable antibacterial and antifungal activity after formulation
- Antibacterial inhibition
- 92.4% for the dog shampoo, and 90.8% for the cat shampoo
- Antifungal inhibition
- 88.6% for the dog shampoo, and 87.3% for the cat shampoo
- Limitation
- Entirely in vitro, with no live-animal testing or clinical cases
- Publication status
- Preprint tied to Veterinary Sciences
A new laboratory study is exploring whether a red-palm-oil-based herbal shampoo could eventually have a role in companion-animal dermatology. In the paper, researchers formulated dog and cat shampoos using red palm oil plus extracts from Rhinacanthus nasutus, turmeric (Curcuma longa), cassumunar ginger (Zingiber montanum), and ginger (Zingiber officinale), then tested those ingredients for antibacterial, antifungal, antioxidant, and anti-inflammatory activity. The headline finding: the finished shampoos showed measurable in vitro activity, but the work stopped short of any live-animal or clinical evaluation. (preprints.org)
That distinction matters. Skin infections remain one of the most common reasons dogs and cats receive topical or systemic antimicrobials, and veterinary dermatology has been steadily moving toward more targeted topical management as resistance concerns grow. ISCAID's current canine pyoderma guidance says topical antimicrobial therapy alone is the treatment of choice for surface and superficial pyoderma, and Merck similarly describes shampoos as a standard vehicle for antimicrobial topical treatment. In other words, the clinical need is real, but the bar for adopting a new shampoo is higher than showing activity in a dish. (pmc.ncbi.nlm.nih.gov)
According to the study, all experiments were conducted in vitro, using established laboratory isolates rather than clinical animal samples, so no animal ethics approval was required. The researchers said C. longa had the highest total phenolic content, R. nasutus showed the strongest antioxidant activity, and C. longa also produced the strongest COX-2 suppression in LPS-stimulated macrophages. For antimicrobial screening, the authors said R. nasutus and Z. montanum emerged as the main antibacterial candidates, while Z. officinale showed the strongest antifungal activity, leading to their inclusion in the final shampoo formulations. (preprints.org)
The finished formulations were reported as stable, homogeneous gels over a three-month evaluation period, with pH values of 7.75 for the dog shampoo and 7.07 for the cat shampoo. The authors reported MICs of 8 µg/mL against Staphylococcus aureus and Staphylococcus epidermidis, 16 µg/mL against E. coli, and 32 µg/mL against Pseudomonas aeruginosa for both formulations. They also reported antibacterial inhibition above 90% and antifungal inhibition near 88%. Still, the organisms tested and assay conditions don't fully mirror the complexity of clinical dermatology, where contact time, coat penetration, biofilm, underlying allergy, endocrinopathy, ectoparasites, and pet parent compliance all shape outcomes. (preprints.org)
Industry and expert commentary on this exact paper appears limited so far, but the broader dermatology literature provides useful context. Recent reviews and guidance emphasize that shampoos can improve outcomes in pyoderma and Malassezia dermatitis, and that topical therapy can reduce reliance on systemic antibiotics when used appropriately. At the same time, reviews of plant-based and natural antimicrobials in companion animals consistently note the same bottlenecks seen here: promising bench data, but limited standardization, sparse safety data, and a shortage of controlled clinical trials. (pmc.ncbi.nlm.nih.gov)
Why it matters: For practicing veterinarians, this study is best read as an early formulation paper aligned with antimicrobial stewardship, not as evidence to switch protocols. It reinforces interest in non-antibiotic or adjunctive topical options for common skin infections, especially as methicillin-resistant staphylococci and recurrent pyoderma continue to complicate care. But before any herbal shampoo could be used confidently in practice, clinicians would need species-specific safety data, irritation and sensitization testing, preservative and contamination controls, batch consistency, and clinical comparisons against established products such as chlorhexidine- or miconazole-based shampoos. Current evidence-based standards still favor those better-studied formulations. (pmc.ncbi.nlm.nih.gov)
There are also practical formulation questions beneath the surface. The preprint lists sodium lauryl ether sulfate and cocamidopropyl betaine among the shampoo ingredients, alongside 5% red palm oil and multiple plant extracts. That raises the usual translational questions for veterinary products: how well the actives remain stable over shelf life, whether they maintain efficacy after rinsing, how they perform on inflamed or barrier-disrupted skin, and whether cats in particular tolerate repeated exposure. The authors acknowledge those gaps and specifically call for checkerboard and time-kill studies, cytotoxicity and irritation testing in pet-derived cells and ex vivo skin, stability work, and controlled in vivo trials. (preprints.org)
What to watch: Watch for a peer-reviewed version of the paper in Veterinary Sciences, plus any follow-on canine or feline trials that measure lesion scores, microbial burden, recurrence, tolerability, and pet parent adherence against standard-of-care shampoos. If those data emerge, this could become a more meaningful antimicrobial-stewardship story; for now, it's a signal of where topical dermatology research is heading. (preprints.org)