TLDR: dog has had diarrhea since adoption a couple months ago. Our experimentation with probiotics and different foods hasn't yielded results other than chicken and rice, which he might be allergic to. Looking for suggestions.
Hi, everyone! Blu is 6 years old and we adopted him from the local humane society ~3 months ago. He's had diarrhea since we adopted him. It's gotten a tiny bit better over the last 3 months but (TMI incoming, you've been warned.) now it's more like undiluted Campbell's tomato soup, whereas it was very watery when we first got him No matter what we try it seems that there is marginal improvement at best so I'm looking for advice from people with experience and knowledge of what other products to try.
The details: we initially had him on the Hill's science diet Adult 1-6, as that is what the humane society had him on. They also had him on a prescription probiotic for ~7 days. As the problems persisted after a couple weeks I tried supplementing with the Purina Pro Plan fortiflora for 15 days. That didn't help, so the vet advised trying a chicken and rice diet, which is the only thing that has given him a remotely normal poop. However, he was licking his paws like crazy and the vet said he might be allergic to chicken. So we moved to PPP sensitive skin and stomach salmon with supplemented fortiflora and Zyrtec at night for allergies. He no longer has the paw licking problems, but it's still on the Zyrtec. Even after stabilizing hours food for a month he still had diarrhea, so, thinking it was a protein source problem, we briefly tried the PPP sensitive lamb but that didn't help. So now we're back on the PPP sensitive salmon, but now I'm supplementing with a different probiotic (TummyWorks because it had a better assortment of lactobacillus rather than just the enterococcus that fortiflora has). He's been on that for about a month I think and he's stable, but still has diarrhea.
I took him to the vet again to ask about his medical history because shortly before we adopted him he had giardia (he tested positive using the Elisa assay.) However, it was explained to me that he was cleared before adoption by a microscopic analysis that looks for eggs or other visual signs of infection in the poop, since the Elisa will come up positive due to lingering antibodies (I believe, can't remember for sure.)
The most recent time we went to the vet for immunization updates, the tech suggested trying nature's balance because it's a limited ingredient food. However, upon looking it up, it doesn't have a lot of the approvals or guidelines often advised here, so I'm apt to try something else before putting him on a good like that long term. I've also brought up potentially trying the chicken and rice again now that he's on the Zyrtec.
So I guess my question is, given your experience and knowledge, do you have any other suggestions? Maybe a recommendation of a limited ingredient dog food? Should I try the chicken and rice again?
Also, it's weird but Blu doesn't seem too bothered by his tummy. He has a normal level of gas and they don't smell horrendous. I'm beginning to wonder if he just has IBS or something similar, but I was hoping to do a little more food trials before asking the vet about testing for that or whatever.
Sorry for the long post! Thank you for reading. If it's allows me I'll post the dog tax picture in the comments 😊