why is my dog not eating and throwing up yellow foamy puke?

my dog is 6 and he hasnt been eating much for the past week or so, hes been laying around and he seems to be shakeing a lot, and at night time or in the morning hes been pukeing up yellow foam, i dont have the money to go to the vet, what should i do?

If the dog has only done this a couple of times today and this is the only symptom, it should resolve itself before tomorrow. Occasional vomit of white or light yellow foam happens, usually because the dog has swallowed something that upset the tummy (like a bug, rock, or plant).BE CAREFUL to observe any other symptoms. Not eating isn't so bad, but not drinking water concerns me. See if the dog is interested in an ice cube. If the dog vomits more than twice or doesn't drink a second day, contact your vet immediately. There are so many things that can cause tummy upset, including pain, stress, and underlying illnesses including diabetes, heartworm and cancer.Is the dog acting disturbed, like running around excited, panting, or whining? Is the tummy swollen? Sometimes the stomach/intestines twist and bloat, which can be life-threatening and is an emergency....!!