# Probiotic Strains from Canine Milk Support Gastrointestinal Health in Weaning Labrador Retriever Puppies

## TL;DR

Probiotics from dog milk help puppies during weaning by improving digestion, reducing stress, and boosting immunity.

## Contribution

Two canine milk-derived probiotic strains were tested for their health benefits in weaning puppies.

## Key findings

- Probiotic-treated puppies had fewer digestive issues and required less antibiotic use.
- Supplementation improved stool consistency and reduced inflammation markers.
- Puppies showed stronger immune responses and faster weight gain.

## Abstract

Weaning is a challenging time for puppies because they are suddenly separated from their mother and must adjust to solid food. During this period, many puppies are at increased risk of digestive problems, which often lead to veterinary visits and antibiotic treatment. In this study, we tested two probiotic strains naturally found in canine milk—Lacticaseibacillus rhamnosus CECT 30021 and Lactiplantibacillus plantarum CECT 30022—to evaluate their ability to support the health of young Labrador Retriever puppies. The probiotics were safe and well tolerated. Puppies that received them had fewer digestive upsets, required fewer antibiotics, and maintained healthier stool consistency than puppies that did not receive them. They also showed signs of lower stress and inflammation, slightly faster growth, and stronger antibody responses to vaccination. Overall, these probiotics supported gut and general health during the sensitive weaning period.

Weaning is a critical developmental stage in puppies often accompanied by gastrointestinal disturbances and empiric antibiotic use. This double-blind, placebo-controlled trial evaluated the safety and efficacy of two canine milk-derived probiotic strains, Lacticaseibacillus rhamnosus CECT 30021 and Lactiplantibacillus plantarum CECT 30022, in recently weaned Labrador Retriever puppies. Forty-nine healthy puppies were enrolled and allocated to receive a daily capsule containing either strain alone, a combination of both, or placebo for six weeks, followed by a six-week observation period. Probiotic supplementation was well tolerated, and clinical, hematological, and biochemical parameters remained within normal ranges. Compared with placebo, the probiotic-treated puppies experienced fewer gastrointestinal infections and required less antibiotic therapy. Supplementation helped maintain normal fecal consistency, prevented increases in fecal calprotectin and inflammatory cytokines, and produced significantly higher fecal short-chain fatty acid concentrations. Systemically, probiotic intake was associated with lower serum cortisol, IL-8, TNF-α, and cholesterol, and stronger antibody responses to vaccination. Probiotic-supplemented puppies also showed faster weight gain during treatment, and this difference persisted after supplementation ended. Overall, these findings indicate that both strains, administered individually or in combination, safely support gastrointestinal, metabolic, endocrine, and immunological health in Labrador Retriever puppies during weaning and may help reduce the need for antibiotics.