Which food is best for small breeds? I cant get him to eat?

[marie923]

My dog is around 3 or 4 years old. Smaller breed (unclear on exactly what kind). But sometimes he goes 2 days without eating, and gets diarrhea. Ive had him for about 1 month now. I get nervous about him, does anyone recomend a certain brand or type of food for this little dog?



Also, I feed him twice a day. Try to keep it around the same time daily, but often hes fed at different times everyday. I walk him 2-3 times a day.
Is it something in our daily routine that could be contributing to his irregular diet??