Alterations in the gastrointestinal (GI) flora can significantly affect the health of humans and animals. Although there are few actual studies showing the benefit of probiotics in dogs with chronic GI dysfunction, the evidence of their benefit is beginning to accumulate.

Probiotics are live bacteria that have been shown to modify inflammatory and immune processes, reduce intestinal pathogens, and improve intestinal health. They typically include a combination of bacteria (eg, Lactobacillus spp, Bifidobacterium spp, Enterococcus spp, etc). In humans, probiotics have been shown to prevent or treat various GI conditions (IBD, IBS), infectious- or antibiotic-induced diarrhea, and allergy to cow's milk. Veterinary medicine is seeing an increase in probiotic use, particularly for the prevention or treatment of GI conditions (eg, diarrhea, IBD) and maintenance of GI health.

The addition of a proven-helpful natural product to repair and maintain GI health in animals is by any estimation good news—if that product is safe and of high quality. Because probiotics are considered "nutraceuticals," they do not undergo rigorous regulatory scrutiny comparable to that for pharmaceuticals. Probiotic efficacy depends on maintaining the life of the organisms in the product. The major hurdle faced by these helpful bacteria is survival through production, storage, and distribution of the product as well as survival of passage through the GI tract to the colon. Unfortunately, not only does survival appear low for many products, but there is an alarming number of discrepancies between the actual contents of some products and label claims.

In a 2011 Canadian report, quality control examinations found that a number of commercial human and veterinary probiotics mislabeled the bacteria types contained in the product and had substantially lower levels of live bacteria than claimed. Of the 25 commercial probiotics examined, only:

  • 21 (84%) listed specific microorganisms (7 labels had misspelled the organisms);
  • 15 (60%) actually listed expected organism numbers on product labels;
  • 27% of products had viable organisms that met or exceeded the number claimed on their label (of which, 2 had a label that properly described the actual contents)

In all, only 2 of the 25 products examined had an acceptable label and bacterial growth that met or exceeded label claims.


Consumers and veterinarians must demand proper quality control and labeling of probiotics from manufacturers in the absence of rigorous regulatory scrutiny of probiotics. However, obtaining a recommendation or prescription for a probiotic from your vet can help ensure getting a high-quality product. Don't be swayed by advertising splash or think that a more expensive product is necessarily a better one, look for a guarantee of the bacterial type(s), number and viability of probiotics on the label. Brand long-time reputation (eg, brand leader "clout") is also a factor that many vets look for when recommending a product. Lastly, to maximize the benefit of the recommended product, it's critical to closely follow probiotic dosing instructions from your vet. Much like antibiotics consistency and timing are very important for success.


Veterinary Professionals learn more on Probiotic Use and Benefits



Rossi G, Pengo G, Caldin M, et al. Comparison of microbiological, histological, and immunomodulatory parameters in response to treatment with either combination therapy with prednisone and metronidazole or probiotic VSL#3 strains in dogs with idiopathic inflammatory bowel disease. PLoS One. 2014 Apr 10;9(4):e94699. doi: 10.1371/journal.pone.0094699. eCollection 2014.

Tremayne J. Practical applications of probiotics. Veterinary Practice News. 2012 May.

Weese JS, Martin H. Assessment of commercial probiotic bacterial contents and label accuracy. Can Vet J. 2011;52(1):43-46.