Will not eat.

10 month old female dog Lethargic, diarrhea, vomiting food up Does drink some, does not eat. This only happend since yesterday.

Hello!  This dog needs to be triaged by an emergency vet - perhaps you can call them. Vomiting makes dogs dehydrated faster than drinking can replace the fluid and this can lead to reduced blood flow through the kidneys very quickly, resulting in some very serious illness. Possible causes of vomiting in 10 year old dogs include pancreatitis (treatable medically), pyometra (treatable surgically), kidney or liver disease (fluids would support), diabetic ketoacidosis, cancer.  However assessment of the need for a drip is a vital immediate step.   All the best and please let us know how you get on.