Frequent vomiting and drinking a lot of water in dogs can be caused by a variety of reasons. First of all, we need to consider that we have accidentally ingested irritating or poisonous foods, such as onions, fungus, etc. These foods may cause irritation to your dog's stomach, leading to vomiting and drinking a lot of water. 
Another possibility is gastrointestinal diseases, such as canine gastroenteritis, gastric ulcers, etc. These diseases can cause gastrointestinal disorders in dogs, such as vomiting and drinking a lot of water. If your dog shows these symptoms, you need to see a doctor for a check-up**. In addition, liver and kidney problems can also cause vomiting and frequent drinking of water. If there is a problem with the dog's liver and kidneys, its metabolic function will be affected, causing it to be difficult to drain water from the body, which can cause vomiting and drinking a lot of water. When the dog has diarrhea, the body may be more uncomfortable, and drinking water frequently is to prevent yourself from becoming dehydrated due to diarrhea. However, if you keep letting your dog drink cold water, it is likely that it will be difficult to stop the more it drinks. Therefore, when the dog has diarrhea, we should provide it with some warm or hot water to avoid aggravating the condition. 
Improper diet can also cause diarrhea and vomiting in dogs. These symptoms may occur if the dog eats expired food or certain foods that are not suitable for him. In this case, it is necessary to change the handling of this type of food as soon as possible, and then give the dog a half-day or a day of observation. There is also the case of vomiting caused by excessive eating. If the dog eats too much or too quickly, it may vomit. Long-term overfeeding can also cause gastroenteritis. Treatment methods include stopping feeding for half a day to a day, feeding the stomach treasure, drinking more water, and letting the dog's stomach and intestines regulate first. 
In summary, frequent vomiting and drinking a lot of water in dogs need to be taken seriously. We need to find out the cause and take appropriate measures to help it. In the process of treatment, it is necessary to pay attention to the changes in the dog's symptoms and adjust the ** plan in time.