If your dog is not eating and is also showing other symptoms of illness, such as vomiting, diarrhea
Dental problems, such as toothache or gum disease, can also cause dogs to lose their appetite.
Stress can also lead to a loss of appetite in dogs.
If you recently changed your dog's diet, it may take some time for them to adjust
If your dog is bored, they may not be interested in eating.
If your dog is in pain, they may not want to eat. If your dog is injured or has any other medical condition that is causing them pain, your vet can recommend pain medication.
If your dog is taking any medication, talk to your vet about whether it could be affecting their appetite.