I would ask your vet directly for what steps they suggest to end the loose stool. Constant loose stool can lead to other more serious health problems. I understand he has had stool samples taken and checked, but has the vet offered any other solutions/suggestions? Like probiotics or supplements? FortiFlora by Purina jumps to my mind and is easily accessible, though moderately expensive. You could also try more "natural" things like Slippery Elm and/or raw goats milk and/or bone broth (homemade), which are my personal go-to for upset tummies.
Over feeding can cause loose stool. You say he is "up to eating 7 cups of food". Have you been increasing his food? I understand he is a growing Dane and needs a lot of food compared to smaller breeds, but perhaps try cutting back and see how his stool does and how his body condition does. He likely isn't retaining much now if he is having such bad loose stool - wouldn't hurt to cut back a cup or 2 and see if it helps. As long as he doesn't drop weight he may just need to eat less. You want to be able to feel and possibly even see a couple ribs, especially since he is a giant breed dog. You want them to be lean, especially while they are growing. He could also just need to switch to a different food. They say if it isn't broke don't fix it, but this isn't that scenario.
But again, this is something you could ask your vet about. I'd be concerned about a giant breed puppy not getting the nutrients they need due to digestive issues, especially for such an extended period of time. If this vet won't help you or offer a plan of action to get this resolved, then seek a second opinion.
Over feeding can cause loose stool. You say he is "up to eating 7 cups of food". Have you been increasing his food? I understand he is a growing Dane and needs a lot of food compared to smaller breeds, but perhaps try cutting back and see how his stool does and how his body condition does. He likely isn't retaining much now if he is having such bad loose stool - wouldn't hurt to cut back a cup or 2 and see if it helps. As long as he doesn't drop weight he may just need to eat less. You want to be able to feel and possibly even see a couple ribs, especially since he is a giant breed dog. You want them to be lean, especially while they are growing. He could also just need to switch to a different food. They say if it isn't broke don't fix it, but this isn't that scenario.
But again, this is something you could ask your vet about. I'd be concerned about a giant breed puppy not getting the nutrients they need due to digestive issues, especially for such an extended period of time. If this vet won't help you or offer a plan of action to get this resolved, then seek a second opinion.
