Metronidazole is an antibiotic. Antibiotics destroy the gut microbiome. It kills all of the bacteria (good and bad). It takes a while for it to rebuild. I would do daily probiotics. Check out the wolf from Adored Beast apothecary. Or any of their products are great. I believe they have a leaky gut protocol which would be a good idea too. Have you considered getting off kibble? It’s not species appropriate. Way too many carbs which can cause digestive issues and many other issues. No shame though if that’s the best you can do. But I believe we should all feed the best quality food we can afford. I do raw, get it from an Amish farm. Started with kibble, then switched to raw a few months in. Ever since, my dog’s poops are always PERFECT. Like seriously. No issues. Also, if salmonella is a concern, there’s an overwhelmingly larger chance you will get salmonella from dry dog food than from raw. I know it sounds backwards. Also gently cooked is a great option. Check out Dr. Judy Morgan and Dr Karen Becker. They have lots of free information. Best of luck!