Purina Veterinary Diets Fortiflora Canine Review

Purina Veterinary Diets Fortiflora Canine Review

Manufacturer’s dog supplement description: “Purina FortiFlora for Canine is a probiotic nutritional supplement for dogs suffering with diarrhea and poor intestinal health. If your dog is suffering from diarrhea due to a change in home circumstances, boarding, eating the wrong types of food, a move, or the use of antibiotic therapies, or if your puppy has soft stools, why not ask your veterinarian how FortiFlora could assist.”

[tabs][tab title =”Overview”]Fortiflora is a supplement for dogs which contains a particular strain of probiotic that, according to the manufacturers Purina, “has been proven to promote intestinal health and balance”.[/tab] [tab title =”How It Works”]Probiotics are “good” bacteria that can displace harmful bacteria from the animal’s digestive tract and form colonies that are helpful to the animal.[/tab] [tab title=”Uses”]Results from clinical studies are conflicting, but some studies show that Fortiflora is helpful in reducing the diarrhoea associated with stress in animals.

Other studies show an enhanced immune response in young and stressed animals, though this result was not repeated in other studies.[/tab] [tab title =”Side Effects”]Most side effects are mild and gastrointestinal in nature. In general, probiotics should be used with caution in immunocompromised animals, but while this product is manufactured in sterile conditions and with known strains of bacteria it can help mitigate the effect of stress (e.g. in shelter animals).[/tab] [tab title =”Dosage”]The product comes as a powder, in prepacked sachets that should be added to food.[/tab][/tabs]

Purina Veterinary Diets Fortiflora Canine

Purina Veterinary Diets Fortiflora Canine ReviewPurina FortiFlora Canine Nutritional Supplement contains the beneficial microorganisms found naturally in your dog’s digestive system to help manage and shorten episodes of diarrhea. Common causes of diarrhea for dogs and puppies include food changes, antibiotic therapy, and environmental stress.

Probiotics are “live microorganisms, which when administered in adequate amounts confer a health benefit on the host” as defined by the World Health Organisation. This definition does stress the requirement for a positive effect to be seen before the product can be referred to as a probiotic for humans, though the same is not true of products for animals. In the USA, probiotics are not controlled by the FDA, as long as no claim to a medical effect is made (in which case they would be regulated as a drug). In the UK, one probiotic is licensed for use in pre-ruminant calves by the VMD.

Purina say that Fortiflora helps to inhibit pathogenic bacteria from colonizing the dog’s intestine, which may help with managing a pet with diarrhea where the illness has been caused by pathogenic bacterial overgrowth (e.g. after dosing with antibiotics, food changes or as a result of stress). It may also have some effects on immune system health.

The major active ingredient in Fortiflora is Enterococcus faecium SF68, a laboratory grown strain of bacteria that inhibits growth of pathogenic bacteria such as Shigella, Salmonella and E. coli by outcompeting them in the intestine, and by producing lactic acid which makes the local environment too inhospitable to survive in for many bacteria.

A large study on shelter cats indicated that dosing with Fortiflora led to fewer of them developing diarrhea than the control group that was given a placebo [1], suggesting that supplementing with Fortiflora was beneficial in preventing diarrhea under stressful circumstances.

In addition, several small studies discussed in Purina’s own literature show that Fortiflora can enhance immune response with higher levels of circulating antibodies, and lower levels of potentially harmful gut bacteria in animals given the probiotic supplement [2]. While encouraging, these trials were all carried out by potentially biased Purina company, and on a small scale.

There is some evidence from other studies (e.g. in piglets [3]) that shows the same immune boost, but does not show the same decrease in harmful bacterial counts as the studies carried out in puppies by Purina.

A separate study in dogs also showed some contrary results [4], in that no decrease in some forms of potentially harmful bacteria was seen, and the amount of a particular pathogen, Campylobacter, was increased substantially in the presence of E. faecium. The strain of E. faecium used in this study was different to the one used in Fortiflora supplement, but the majority of the qualities are the same, otherwise the two bacterial types would be different species rather than just different strains.

Fortiflora Canine Supplement

Fortiflora is packaged in 1g sachets, and those should be added to food. The product is formulated using an encapsulation process that ensures much of the active ingredient remains active while in storage, and makes it safely to the gut of the dog, rather than being broken down by digestion processes in the pet’s stomach.

The sachets contain a large number of other chemicals in addition to the active bacteria. No quantities are given, save that 1g is guaranteed to deliver 108 CFU/g of Enterococcus faecium SF68:

Animal digest – this is digested animal protein which is added to make the product palatable to dogs.

Enterococcus faecium – the active bacterial strain in the probiotic. This strain of E. faecium is laboratory produced and does not carry any genes for antibiotic resistance [2] (unlike some “wild type” E. faecium which have a variety of antibiotic resistances [5]).

L-ascorbyl-2-polyphosphate – a source of vitamin C. Vitamin C is an antioxidant and is also important in a large number of cellular reactions for dogs, including the formation of collagen, and is thought to play a role in immune function.

Brewers dried yeast – Brewer’s Yeast is a fungus called Saccharomyces cerevisiae that is used to make beer. When given as a nutritional supplement, yeast is deactivated and is a good source of B complex vitamins, protein, chromium and selenium. B vitamins are important in the synthesis of a number of structures, including amino acids, antibodies and red blood cells as well as being crucial to the metabolism of fats and carbohydrates.

Vitamin E supplement – Vitamin E is an antioxidant and is protective against the effects of free radicals. It has a role in gene expression and circulation (as it inhibits platelet aggregation).

Other active ingredients: zinc proteinate (a zinc salt given to prevent zinc deficiency); beta-Carotene (a yellow-orange pigment, and precursor molecule to vitamin A); manganese proteinate (a source of Manganese – needed for normal skeletal growth and maintenance and metabolism of carbohydrate and protein); ferrous sulphate (an iron supplement); copper proteinate (a copper supplement); calcium iodate (a source of iodine, which is necessary for the normal functioning of the thyroid gland); sodium selenite (a source of selenium).



  1. Jan S. Suchodolski. Review: Probiotics in GI Health. Western Veterinary Conference 2013. [pdf]
  2. Purina Scientific Review: Benefits of probiotics in your canine and feline patients. [pdf]
  3. Scharek L, Guth J, Reiter K, Weyrauch KD, Taras D, Schwerk P, Schierack P, Schmidt MF, Wieler LH, Tedin K. Influence of a probiotic Enterococcus faecium strain on development of the immune system of sows and piglets. Vet Immunol Immunopathol. 2005 May 1;105(1-2):151-61. [study]
  4. Rinkinen M, Jalava K, Westermarck E, Salminen S, Ouwehand AC. Interaction between probiotic lactic acid bacteria and canine enteric pathogens: a risk factor for intestinal Enterococcus faecium colonization? Vet Microbiol. 2003 Mar 20;92(1-2):111-9. [study]
  5. Handwerger S, Raucher B, Altarac D, Monka J, Marchione S, Singh KV, Murray BE, Wolff J, Walters B. Nosocomial outbreak due to Enterococcus faecium highly resistant to vancomycin, penicillin, and gentamicin. Clin Infect Dis. 1993 Jun;16(6):750-5. [study]

Disclaimer: The purported effects of the supplements or ingredients discussed in this article may, or may not, have been subject to rigorous scientific investigation.  This article is an introductory document for educational purposes only which is not intended to be a scientific review either endorsing or refuting the claimed effects of the supplements or ingredients. The information is NOT to be used for diagnosis or treatment of your pet. You should always consult your own veterinarian for specific advice concerning the treatment of your pet. The supplement has not been tested or tried by the author(s) of the content/review, and are not endorsed or recommended in any way.

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