Then I ran across a great article on Whole Dog Journal about probiotics called It's All In How You Make It. It speaks at length about using lacto-fermented vegetables in your dogs diet, and it's good for you too! Rather than using a sugar or dairy based carrier I learned that you can use unrefined sea salt! The unique thing about lacto-fermented vegetables is they qualify as both a prebiotic and probiotic and they are cheaper and easier to make then you think.
I purchased my crock from Cultures for Health.
I purchased the unrefined sea salt from Vitacost.com. When I first bought these they came in a 6-shaker case, but I'm already on my 3rd or 4th shaker. Now it looks like they come in single bottles. It's also now purchasable in 1 pound bags.
May 6, 2015 Edit - The Lima Unrefined Sea Salt is no longer available through Vitacost, I found many reasonable sources of unrefined sea salt on Amazon.com.
I use cucumbers because of their ease to purchase, grind and crush through my juicer and how quickly they are ready to use. I go through a batch in a little over a week, they only take two hours to adequately ferment , but I leave it mine for 24 - 48 hours, then store it in the refrigerator in a seal-able container. Each dog gets a couple Tablespoons scooped out daily with their dinner. They will lap it right out of the bowl by itself, they are quite tasty! The batch pictured below is from 6 large cucumbers and I used 2 Tablespoons of unrefined sea salt as the starter per gallon. The valve on the top of the crock lets air escape without letting air in. I left the skins on because I grew these cucumbers myself, but I peel those I buy from the store.
If you want to read more about yeast in dogs, you can read this copy of the WDJ article titled Canine Candida.