There isn’t a one size-fits-all-solution when dogs begin to refuse food and it depends on health status, but at least one (and hopefully more) of these things can help:
- Change the diet (be sure it’s balanced) Dogs can associate feeling nauseous with something they ate in the past that seemed to have caused the nausea, and if that something happens to be the usual diet, food aversion happens quickly.
- Change the feeding bowl. A flat plate can seem attractive to a dog who usually eats from a bowl. Some dogs refuse any type of feeding utensil, but will eat food off a placemat on the floor.
- Sometimes an area of a room or even an entire room becomes a “bad place”. Negative experiences like nausea and vomiting may be related to that location. Try another place in that same room, or feed the dog in different room.