What do dogs vomit when they have a fever?

What dogs vomit when they have a fever depends on the situation. If the fever is caused by a cold, the dog will generally not vomit. If diseases such as canine distemper cause the dog's body temperature to rise, the dog will vomit yellow water. It is best to take your dog to the hospital for examination to confirm the specific cause of the dog's fever and then treat it.