A study published in Veterinary Immunology and Immunopathology investigated the long-term effects of early exposure to Lactobacillus rhamnosus GG (LGG) in an experimental canine model of atopic dermatitis (AD).
Study Design
In this controlled Beagle model, pregnant bitches and their puppies received LGG during the first six months of life. The control group did not receive probiotics.
All puppies were sensitized at a young age to house dust mite (Dermatophagoides farinae) and later also to grass pollen and ragweed.
Three years after discontinuation of probiotic administration, a follow-up study was performed. The dogs underwent renewed allergen exposure, and both clinical signs and immunological parameters were evaluated.
Key Findings
- Significantly lower clinical scores (CADESI) in the probiotic group following allergen challenge
- No difference in allergen-specific IgE levels between groups
- Lower IL-10 production in the probiotic group, with levels closer to those observed in healthy control dogs
- No significant differences in TGF-β1 between groups
Interpretation
Although early probiotic exposure did not prevent allergen sensitization (IgE levels remained comparable), it resulted in sustained reduction of clinical severity — even three years after discontinuation.
The findings suggest that early microbial modulation may have a lasting impact on immune regulation in dogs genetically predisposed to atopic dermatitis.
Conclusion
Early administration of LGG in a high-risk model of atopic dermatitis resulted in long-term clinical benefits. Further studies in dogs with spontaneous atopic dermatitis are needed to confirm the clinical relevance in everyday practice.
References
1.Olivry, T.; Mas-Fontao, A.; Aumayr, M.; Ivanovova, N.P.; Mitterer, G.; and Harwanegg, C. Validation of a Multiplex Molecular Macroarray for the Determination of Allergen-Specific IgE Sensitizations in Dogs. Vet. Sci. 2024, 11, 482. https://doi.org/10.3390/vetsci11100482
2.Welters, M.; Mas-Fontao, A.; Auxilia, S.; and Olivry, T. Composition heterogeneity and low-molecular-weight allergen content of Dermatophagoides farinae house dust mite allergen extracts used in veterinary medicine. Vet. Sci. 2025, 12: 824. https://doi.org/10.3390/vetsci11100482
