Thank you for the prompt reply.
When a large breed dog is showing symptoms as you describe, we certainly have to be concerned with the possibility of gastric bloat, but that is not a condition that continues for a week, so if the stomach was enlarged last week, that is less likely. Certainly, there are other abnormalities that can make the abdomen appear swollen, such as tumors, internal bleeding, or even gas in the GI tract. The other symptoms he is showing would make you think that the GI tract may be involved. Drooling can be a sign of nausea and the soft stool he is passing may indicate the colon is involved as well. If these symptoms continue, it definitely warrants an evaluation by his veterinarian for a definitive diagnosis and appropriate treatment.
In the meantime, I would fast Jackson to give his GI system a rest. Since he is an adult dog, a 12-24 hr fast will not hurt him and will let his gut calm down. Continue to offer small amounts of water at a time. When you do begin feeding him again, you will want to offer frequent, small meals of something very digestible for him. These would include items like boiled hamburger or chicken and rice or pasta. No sauces or gravies, but a little non greasy broth would be OK. If the stools improve, I would continue that for a few days and then slowly wean him back onto his normal food and feeding schedule.
I hope this is helpful. Please let me know if you have ANY other questions. My goal is to give you 100% satisfaction and if you are not yet satisfied, please reply so I can clarify for you.
My posted replies are for general education only and not meant as a diagnosis. Only after a thorough veterinary examination can a diagnosis for your pet be made and specific treatments be advised or medications be prescribed.