Probiotics for Dogs and Horses – New Evidence

The use of probiotics is widespread across species, including humans. They are usually based on lactic acid bacteria such as lactobacilli, bifidobacter and enterococci, or on the yeast Saccharomyces cerevisiae. The effect of bacterial probiotics have been mixed. In terms of livestock production most work has been carried out on poultry and piglets where variable responses to nutrient digestion and pathogen exclusion have been noted. The effects are less documented in other species and in live culture yogurts, advertising reference to any probiotic action has been removed.

However there is an increasing direction in research on the potential effects of probiotic therapy. For example, research has been carried out to treat atopic eczema in infants, other research is looking at the combination of probiotics and antibiotics to treat some microbial diseases.

In veterinary medicine probiotic therapy is becoming increasingly popular and commercial products are available for cats and dogs. The main reason is that antibiotics, although extremely effective in eliminating targeted pathogens, will also cause major disruption in the intestine resulting in changes to the microbial populations and the intrinsic immune system. Earlier research has shown the benefit of a probiotic based on Lactobacillus rhamnosus on some canine disorders.
Despite this there are few studies on probiotic therapy on dogs, but a new research work has added to our knowledge.

A study, published in the International Journal of Biosciences* this year, monitored the effects of probiotics containing lactobacilli, bifidobacter and enterococci on blood parameters, in Persian Shepherd dogs. Although blood protein and albumin remained unaffected, the inclusion of a dietary probiotic caused a significant decrease in a2- and B1- globulins, and an increase in B2- and y- globulin. Overall the effect was to reduce systemic inflammation and to increase serum immunoglobulins and white blood cell count, thereby potentially improving the function of the immune system.

This piece of research adds to the database for dogs, where it has been shown that some lactobacilli can survive transit through the gut, adhere to the intestinal mucus and inhibit in vitro growth of some pathogens.

It is always difficult to transfer biological systems across species, especially when they are as diverse as poultry, humans and canines. So it is useful to have species-specific data, as in this case, which highlights effects in the dog, but also draws parallels with work in humans. It gives greater confidence that the products do have an effect.

However, with horses the evidence points to different probiotic types and effects. Lactobacillus pentosus was shown to cause diarrhoea in neonatal foals whilst Lactobacillus rhamnosus (positive effect on canine disorders) does not appear to colonise the gut as it does in cats & dogs. However Bacillus cereus does appear to colonise the caecum.

With the horse it is the fibre fermenting microbes that have a positive probiotic effect. Yeasts, especially Saccharomycee cerevisiae, can survive the journey to the hindgut where they actively ferment fibre and so help promote digestive efficiency. They do need to be constantly supplemented, as they cannot colonise. Because of the difference both in the diets and the gut modifications to digest those diets, between different species, it is perhaps not surprising that one probiotic type is not suitable in all cases.

The inclusion of fibrolytic probiotics should be used for horses where they can have an impact in the hindgut, whilst lactic acid producing probiotics have a greater role to play in dogs (and cats) where the immune-stimulatory impact has greater relevance. It is always worth discussing the choice of probiotic with your feed provider.

Julliand, V. Pre- and pro- biotics for equine practice. Horse health nutrition: Third European Equine Health & Nutrition Congress, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium, 17-18 March, 2006, 2006, pp 18-26
Loes, N. The “inside poop” on probiotics. Veterinary technician. Proceedings of the North American Veterinary Conference, Orlando, Florida, USA, 16-20 January 2010, 2010, pp 63-66,
Saam Torkan1, Mohsen Jafarian Dehkordi, Faham Khamesipour .
The effects of probiotics in the blood chemistry of Persian Shepherd dogs . International Journal of Biosciences. 2014. 4 (2). 205-210

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