eight months of chronic soft stool in our 4yo poodle, three diet switches, two vets, and i finally caved and saw a veterinary nutritionist, sharing where we are because i wish someone had told me to skip the bouncing around

Otis is a 4yo standard poodle, intact male, 52 pounds, otherwise totally healthy. starting around last september his stool went from picture perfect to soft and inconsistent, sometimes pudding consistency, sometimes mucus, occasionally a streak of blood once or twice a month. no other symptoms. eating well, drinking normally, full energy, gaining weight if anything. our regular vet ran a fecal, came back clean, said it was probably food sensitivity and to try a limited ingredient diet.

What we tried in order. first switch was to a salmon and sweet potato LID kibble, ran it 8 weeks, no change. second switch was to a hydrolyzed protein script diet, ran it 10 weeks, marginal improvement maybe but still not normal. third was a homemade balanced diet we worked out from a Petdiets consult, ran it 6 weeks, actually got worse. by month 6 i was googling at midnight and convinced he had IBD or a tumor or who knows what.

What changed. our second opinion vet pushed us to see a board certified veterinary nutritionist instead of continuing to chase diets, and that consult was different in a way i did not expect. she ordered a full GI panel including B12, folate, TLI, PLI, and a bile acid test before recommending any new diet. the panel came back showing low B12 and slightly low folate, which she said pointed at small intestinal involvement rather than dietary sensitivity specifically. she had us start B12 injections weekly for 6 weeks and put him on a different therapeutic diet with specific fiber profile, and within 3 weeks his stool was normal for the first time in 8 months.

So my actual questions for people who have been through this. one, did anyone else go through multiple diet switches before getting the bloodwork that finally pointed at the cause, because i feel like we wasted 6 months. two, for people whose dog ended up with confirmed IBD or chronic enteropathy, what was the diagnostic path and did diet alone manage it long term or did you end up needing meds. three, has anyone had a vet nutritionist consult and felt it was worth the cost, because ours was $380 and i would have spent it 7 months earlier if i had known what i know now. trying to give better advice to a coworker who is starting the same loop with her bernese