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Cornell Richard P. Riney Canine Health Center

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The power of probiotics

Benefits for the whole dog

Advertisements touting the benefits of probiotics are plentiful claim that they are a cornerstone of preventative care. Probiotics boost the healthy gut bacteria that help digest food. They are a well-known therapy for diarrhea and gastrointestinal upset. More recently, they’ve been found to counter urinary tract infections, immune system disorders and even anxiety.

In fact, mental health is one of the most exciting revelations about probiotics. Your dog’s gastrointestinal tract and brain are in constant contact, and proper microorganisms in the intestines can help with mental and emotional regulation.

The bacterium called bifidobacterium longum, commonly known as BL999, is at the forefront of this discovery. Dr. Ragen T.S. McGowan, a pet behavior researcher for Nestlé Purina, reported that dogs who took BL999 were less likely to bark, jump, spin or pace in situations that normally caused them distress. They were also more likely to explore a new environment.

Choosing wisely

The most widely known probiotics are the live cultures found in yogurt, but they are also available as nutritional supplements. Labels should include an expiration date, the exact species, the number of microorganisms in the product and a guarantee for the number of live organisms. The manufacturer should be able to provide support for the efficacy of the product, preferably a study by an external, accredited researcher.

Joseph J. Wakshlag, D.V.M. '98, Ph.D. '05, professor of clinical nutrition and sports medicine and rehabilitation, recommends Fortiflora and Proviable as probiotic products that have studies showing their efficacy. He says that VSL#3 may be helpful for patients with irritable bowel disease.

Probiotics are measured in colony forming units, or CFUs. The current recommendation for dogs is 1-10 billion CFUs a day.

Most dogs willingly eat probiotics added to their food. If your dog is pickier, a capsule form can be easily disguised in a treat.

Feeding probiotics

Probiotics can be given proactively if you know a stressful event is coming up, such as boarding while you are on vacation or moving. Start giving the probiotics several days in advance so that your dog already has an ideal gastrointestinal tract.

You can also give probiotics daily as part of your dog’s long-term health care.

Digestive health

Probiotics normalize the conditions in the intestines by changing the local acidity of the digestive tract and releasing short-chain fatty acids.

This gives dogs a leg up if they end up ingesting harmful bacteria such as Salmonella. Probiotics help inhibit the growth of these bacteria by competing for the same nutrients and resources. Boosting the populations of helpful bacteria limits the nutrients available for the bad bacteria and reduces their numbers to levels that your dog can tolerate better.

Immune health

Your dog’s gastrointestinal tract contains about 70% of their immune system, putting it on the front line for preventing pathogens from accessing the rest of the body. By normalizing the conditions in the digestive system, probiotics allow the immune system to function properly.


Probiotics are safe. Studies for any given product should show that the probiotic does not promote antibiotic resistance in other bacteria and that it is not pathogenic itself.

Severely immunocompromised dogs should only be given probiotics with caution and under veterinary supervision, as their immune systems may not be able to handle the strain of any bacterial load, regardless of its pathogenicity.

Conditions that may benefit from probiotic treatment

  • Allergies

  • Anxiety
  • Bad breath
  • Coat quality
  • Diarrhea
  • Immune disorders
  • Intestinal inflammation
  • Irritable bowel syndrome
  • Liver disease
  • Obesity
  • Skin disorders
  • Urinary tract infections

Probiotic species beneficial to dogs

  • Bacillus coagulans
  • Bifidobacterium animalis (strain AHC7) helps with acute diarrhea
  • Bifidobacterium bifidum
  • Bifidobacterium longum (BL999) helps with anxiety
  • Enterococcus faecium (strain SF68)
  • Lactobacillus acidophilus improves stool quality and frequency
  • Lactobacillus casei
  • Lactobacillus plantarum
  • Lactobacillus rhamnosus (strain LGG) maybe effective for diarrhea, since it is beneficial for humans with diarrhea

Probiotics vs. prebiotics

Probiotics are beneficial microorganisms that live in your dog’s intestines. Prebiotics are fiber upon which the probiotics feed. Both occur naturally, but can be given as supplements or added to your dog’s food.

This article has been reprinted with permission from the Cornell University College of Veterinary Medicine’s DogWatch newsletter, published by Belvoir Media Group. When you become a member of the Riney Canine Health Center, you will receive a free subscription to DogWatch.