If the chihuahua is lethargic and eating grass, it may have an upset stomach. Try soft foods, some chicken broth, and rice. If that does not work, call the vet.
Is your dog eating? Vomiting? Feverish? I'm worried about the lethargy, that's NOT a good sign. Try a spoonful of plain yogurt once a day, but I'd see a vet.
Well the best thing you can do is take him to the vet or call a special number where you can ask medical questions about dogs. You dont want to feed him the wrong meds.
It will be very weak and it will not want to eat.I would give it a dog aspirin or take it to the vet.You can get the dog aspirin at wallmart for about 2 dollors they are in a big bottle.Do that and take time to give it attion.Dogs .