Could Your Patient’s Allergies Start in the Gut?

Faecal Short-Chain Fatty Acids Show Promise as Biomarkers for Canine Atopic Dermatitis

A February 2026 study published in Veterinary Dermatology has identified a potential connection between gut health and canine atopic dermatitis (cAD)—one that could reshape how we approach both diagnosis and treatment of this challenging condition.

The Gut-Skin Connection

The concept of a gut-skin axis has gained momentum in human medicine, with growing evidence that intestinal health directly influences skin conditions. Short-chain fatty acids (SCFAs)—metabolites produced by beneficial gut bacteria—serve as key messengers in this communication pathway.

In humans with atopic dermatitis, researchers have documented both lower SCFA levels and their predictive value for disease development. Until now, parallel research in veterinary medicine has been limited.

What Are Short-Chain Fatty Acids?

SCFAs represent the primary metabolic products of beneficial gut bacteria as they ferment dietary fiber. The three main types measured in this study were:

• Acetic acid — produced by various bacterial species, supports epithelial barrier function • Propionic acid — generated primarily by Bacteroides species, exhibits anti-inflammatory properties
• Butyric acid — produced mainly by Clostridium species, serves as the primary energy source for colonocytes

These compounds don’t just stay in the gut. They enter systemic circulation and influence immune function throughout the body, including the skin’s inflammatory response.

The Research Findings

The preliminary study examined fecal SCFA concentrations in 25 client-owned dogs with diagnosed cAD compared to 27 healthy controls. Using gas chromatography analysis, researchers found significantly lower concentrations of all three SCFAs in dogs with atopic dermatitis:

• Acetic acid: p < 0.001 • Propionic acid: p = 0.0271
• Butyric acid: p < 0.001

This represents the first documentation of altered fecal SCFA profiles in canine atopic dermatitis, mirroring patterns observed in human patients with the same condition.

Clinical Implications

The study authors suggest these findings could have dual applications: as biomarkers for disease risk assessment and as therapeutic targets for intervention.

Biomarker potential: SCFA testing could theoretically identify dogs at higher risk for developing atopic dermatitis before clinical signs appear. In human medicine, such metabolic profiling is already being investigated for predictive purposes.

Therapeutic targeting: The reduced SCFA levels suggest that interventions aimed at restoring beneficial gut bacteria—through probiotics, prebiotics, or dietary modification—might influence skin health outcomes.

The Microbiome Treatment Landscape

These findings arrive as veterinary medicine shows increasing interest in microbiome-based interventions. Current research areas include:

• Strain-specific probiotics for immune modulation • Prebiotic supplementation to promote SCFA production • Fecal microbiota transplantation in severe dysbiosis cases • Precision nutrition based on individual microbiome profiles

The SCFA connection provides a mechanistic framework for understanding why some microbiome interventions show promise in managing allergic skin conditions.

Study Limitations and Future Directions

As a preliminary investigation with 52 total subjects, this research establishes proof of concept rather than clinical protocol. The authors recommend larger-scale validation studies to confirm these findings and determine whether SCFA testing could become a practical diagnostic tool.

Key questions for future research include optimal timing for SCFA assessment, correlation with disease severity scores, and whether therapeutic interventions can successfully normalize SCFA levels in affected dogs.

Looking Forward

The gut-skin axis represents an evolving frontier in veterinary dermatology. While SCFA testing isn’t yet ready for routine clinical use, these preliminary findings suggest we may be moving toward a more comprehensive understanding of atopic dermatitis—one that considers the patient’s entire microbial ecosystem.

For practitioners managing complex dermatology cases, this research reinforces the value of considering gastrointestinal health as part of the diagnostic workup, particularly in cases where traditional approaches have shown limited success.

This research was conducted by veterinary dermatology specialists and published in Veterinary Dermatology, February 2026. For comprehensive continuing education on dermatology and internal medicine topics, explore our on-demand course library.

Official Sources

• Study Citation: Preliminary Measurement of Faecal Short-Chain Fatty Acids in Dogs With Canine Atopic Dermatitis. Veterinary Dermatology, February 2026. DOI: 10.1111/vde.70015 • PubMed: PMID: 41527507 • Journal Publisher: Veterinary Dermatology