Over the last few years, canine probiotics have skyrocketed in popularity, but with the recent controversy surrounding the health claims associated with human probiotics, do they really work?
Any microorganism that can benefit the health of the host animal can be defined as a probiotic. The most common probiotics for both humans and dogs are the Lactobacillus and Bifidus genera of bacteria that naturally reside in the intestine. These microorganisms are widely accredited with increasing the population of 'friendly bacteria' and reducing the growth of problematic pathogens. Preliminary studies also suggest that probiotics may benefit dogs suffering from diarrhoea, IBS, colitis and lactose intolerance and may help to reduce blood cholesterol and blood pressure and even the incidence of colon cancer!
Unfortunately, these claims have come under a lot of fire recently due to the lack of conclusive evidence. In all, the European Foods Safety Authority (EFSA) has rejected 260 health claims due to lack of evidence. As a result, a number of well know probiotic yogurt producers in the UK have had to overhaul their packaging and advertisements to remove any suggestions of health benefits. As you might expect, studies on dogs are even less common and even less conclusive.
Personally, I have seen extremely mixed results in dogs. While some dogs don't seem to react at all, or may even become ill on probiotics, many have shown significant and often rapid digestive improvements and I know of many owners and breeders that absolutely swear by them.
Probiotics for dogs can be found in a variety of forms. The simplest probiotics are plain live yogurt and cottage cheese which have always been popular supplements amongst dog owners. They are very easy to get hold of and can be fed daily alongside any diet.
Commercial probiotics are available as capsules, tablets, powders, yogurts or drinks. Most human probiotic supplements can be used for dogs since many of the same strains of bacteria can be found in both people and dogs (please note that dogs will need less than the normal human dosage - about half for a large dog to a quarter for a smaller breed). Nevertheless, the balance of the dog's intestinal bacterial is by no means the same as ours so a canine-specific probiotic is always best. For dogs, good probiotic strains to look out for are B. animalis, L. acidophilus, L. rhamnosus, L. salivarius, L. fermentum and L. reuteri although many more are available.
Dog food manufacturers have also noticed the increasing popularity of probiotics and have started adding them to their diets. But probiotics aren't like other ingredients - they are alive and must stay alive if they are to work. For this reason, foods that contain them must be produced and treated with care if the probiotics are to survive. Unfortunately though, some manufacturers add them more for marketing purposes than for actual benefit and don't provide the probiotics with the special care they need.
A number of factors can dramatically effect the survival of probiotic bacteria, but by far the most important in dog foods is temperature. Most probiotic species suffer at temperatures of over 45-50°C but tinned foods are cooked at a minimum of 100°C and most extruded foods are subjected to temperatures in excess of 130°C. In these cases the probiotic must be added after cooking if any are to survive but even then if it is subjected to any high temperatures during storage, transportation and preparation the probiotic may be rendered completely useless.
Whether the probiotics are in the form of a supplement or present in the complete food, make sure you pay attention to the storage instructions on the packaging. All probiotics are best stored at a cool temperature but some need to be kept in the fridge in order to survive.
Even after it has made it to the dog's bowl, manufacturers need to take care with their formula to ensure that the extreme acidity of the stomach acid doesn't wipe out the bacteria before they get to their new home in the intestine. The dog's stomach has a very low pH of just 1-2 which is enough to kill almost all bacteria and unless the probiotics are fed in conjunction with abundant carrier molecules like dietary fibres, very few will survive.
So, to make sure your dog gets the most out of his probiotic, remember that quality is key. Look for supplements that are specifically designed for dogs and not just re-branded human probiotics and if you're paying extra for a food that contains a probiotic, make sure that it has been produced with the bacteria in mind.
For further information on probiotics for dogs, a comprehensive guide can be found here.