Thanks for posting on HealthCareMagic. I am sorry to hear about your daugther. During illness when the child does not eat properly, the body has to manage nutrition from elsewhere and converts fats to ketones which act as the food for brain. That is probably the reason for your child to have 4+ ketones. All that has to be done is to give her feed properly. I would also insist giving her ORS to help her regain salt and water imbalance. At times it is extremely difficult to find the vein in small children and in case of a dehydrated child finding a vein is tougher. Your daughter seems to be suffering from an infection. Most of these conditons are caused due to viruses and hence antibiotics are ineffective. Without listening to her chest and examining her abdomen, it is hard for me to comment further. Zofran (Ondansetron) is intended to reduce the nausea and vomiting and would help her feed. It is unlikely that the doctor did not prescribe antibiotic to avoid interaction with Zofran, rather probably he thought that the antibiotics are not required, and has not given her one. Do not worry about it. I would insist you to give her steam inhalation as it would help in diluting the cough and give her relief. Hope that helps. Feel free to revert back in case of further queries if any.