My dog (6yo - small-medium size terrier cross) had a loss of appetite and sickness start about 6 weeks ago that was ongoing for 3 weeks. He had a vet feel his stomach, and take him for a scan and X-ray and they couldn’t find anything. We attempted anti sickness medicine but after a few days he was still sick and diarrhoea began (ongoing for 5 days). Vet said it must be gastrointestinal and we stopped the medicine and he seemed to eventually get a bit better on his own a few days later. He’s struggled to go back to having much of an appetite (used to always be fed kibble mixed with pate, then had boiled chicken since illness began) he refused any kibble, but started eating some healthy wet dog food over the last 10-14 days. But now the last 5 days he’s gone back to not having any appetite, turning away food and since yesterday afternoon throwing up stomach bile when we’re about to give him food. He has obviously lost a lot of weight over this period of 6 weeks because we can barely get him to eat.