I like the larger container best!I just started using this probiotic after our holistic vet recommended the product. My lab has issues with pancreatitis and is on a low fat diet, so far so good.I adopted my sweet little long hair chihuahua 5 years ago. She was 8. It didn't take long to discover She had some digestive issues. She also has hip displaysia, and I believe this is due to inbreeding. Anyway, I followed different veterinarians advice including changing her diet to the raw diet. The raw diet helped a little, but she would still get constipated and sometimes really be in pain. I finally took her to a naturopathic vet and he diagnosed her with IBS. He recommended I give her this product once a day and 1/8 t of physillium husk powder with both meals. It has helped her so much, she hasn't had stomach pain and has gone regularly for the past 6 months.Improves tummy issues, diarrhea issues for my pup.I use this when I get new foster pups to help prevent diarrhea from the sudden food change. It really helps without having to pay for a vet visit and without getting any toxic medication that does more harm than good in the long run.I have been using this for years on my dog. One scoop twice a day seems to keep her gut in check.I have a 7yr old Doberman with grass and other environmental allergies, possibly food allergies (eliminated chicken from her diet). Always had an itchy belly, especially when pollen count was high. For the past 3 years, I have been taking her to an allergy specialist and she gets injections + pills (Atopica). This year the allergy doc tested her skin and it came back positive for bacteria and yeast, so I knew that a probiotic could probably help this. I started her on this probiotic a few months ago and it really seemed to calm her allergies, even through the fall high pollen season. Still itchy, but recovers faster and no longer itches to the point of open sores/scabbing. I don't like giving her Atopica bc I hate big pharma; I was able to pretty much stop giving her Atopica and got better results with just the injections + probiotics. Who knows, as the good bacteria increases in her gut, maybe I can cut out the injections too. Had a little sticker shock with the price at first, but the results are amazing, it seems to last a long time and I now have no problem with the price, it is a good deal. The container is very small, but lasts a long time and that is with giving her 2 scoops mixed with food once every day. Initially I gave her 2 scoops in the morning, and 2 scoops again in the evening for several weeks, then went to maintenance dose.I also give her Vitamin E, fish oil, a doggie multivitamin daily and I use Douxo Chlorhexidine PS Shampoo (available for purchase on Amazon). After she plays outside, I wipe her belly down with cow udder wipes (I get these from her allergy doc, but maybe could purchase from a farm supply store?).My service dog will soon be 13 years old and I've been giving him RxBiotic for 7+ years. It helps his digestion and overall health. It was recommended by our vet.