How to stop my dog from eating his poop and help him gain weight?
This is a repeat question so I will copy and paste my previous response since you deemed it a helpful answer.
Giving the pet 1 tsp of meat tenderizer in the food daily sometimes stops the pet from coprophgia (eating of ones own stool). You can also easily purchase Forbid online (i.e. Amazon). I am unsure if his stools are loose or normal, but if loose I would also recommend deworming him (i.e. Fenbendazole) for possible intestinal parasites.
Pets that are underweight should be checked and treated for parasites as the first step. If parasites are not the cause then other possible causes are: exocrine pancreatic insufficiency, Addison's disease, and Vitamin B deficiency just to name a few. It is unfortunate that you don't have a vet available because none of those disorder would be able to be detected and treated without medical care.
If you find yourself at a dead end and nothing is working and your pet is ill because of this continued issue, then perhaps flying your pet out for care elsewhere, or making a road trip to get your pet the care he needs, is the next best step. I wish you all the best!
Updated on September 23rd, 2025