My dog won't eat only drinking water. What is wrong

Usually they are sick and need a vet or over fed. I give many more details in the sticky at https://www.askmehelpdesk.com/dogs/information-articles-our-dogs-expert-labman-53153.html#post254171

Tempting it with rich food is nearly always the wrong thing to do.

Purple, how old is your dog and how long has your dog gone without eating? If your dog is an adult & seems its normal self, but hasn't eaten one or two meals, and the temperatures outside are extremely hot, more than likely, he/she is uncomfortable due to the weather. Just give your dog plenty of water. He/she will eat when hungry enough. If he/she continues not to eat for more than a day or two, please do as labman suggests. Your vet will need to do an examination to figure out what is causing this. If your dog is a puppy which has refused to eat for a day, give your vet a call.

I had the same problem with my dog. I took her to the vet and the vet said she had an extremely high temperature and gave me some antibiotics to lower her temperature. The next day I put out her food and she ate, so you should really see the vet.