Some breeds of dogs do not need a high percentage of food every day but they do need good food which will provide essential nutrients to keep them healthy.
The smaller breed of dog, if they have a large amount of treats, will start to react by leaving their meals due to being overfed at other times of the day.
Sometimes a dog may decide he is bored with the same food being given to him and a change of food is all he needs. Add a few carrots or pieces of apple to his dinner and watch to see if this wakes up his appetite.
Take away all his treats until you feel he his back to his normal eating pattern.
When an owner realises the dog is picking at his or her food there is a tendency to think the dog is ill. This could be true and if your dog is not well you will recognise the signs of listlessness, sleeping a lot or vomiting. If this happens then a visit to the veterinary surgeon is essential to put your mind at rest and to give your dog good quality health care.
It is important to remember a small dog only needs small portions of food daily. If you are unsure, check with your vet.