Dogs may throw up after drinking water for a variety of reasons. Dogs may truly vomit (evacuating the contents of their stomach) or they may simply regurgitate (bringing back liquid or food because they have not swallowed it properly).
Regurgitating water soon after drinking may mean a problem with the oesophagus (food pipe). Vomiting water after drinking and not eating usually indicates a problem with the stomach or intestines.
What causes a dog to throw up?
Dogs can throw up for many reasons. If your dog drinks lots of water, especially very cold water or after exercise, this can fill the stomach too quickly and cause them to throw some of it back up straight away. If your dog does this a lot, you can slow down your dog drinking by placing a large, clean stone in their water bowl, so they have to lap around it, or give them a small amount to drink at a time.
Your dog may also drink a lot of water if they are feeling unwell (nauseous) to try to make themselves sick. This is also why dogs sometimes eat grass. It can be a dog’s way to clear out toxins, if they have eaten something that is causing a stomach upset.
There are lots of more serious reasons why dogs vomit, including infections, toxins, blockages, metabolic disease (such as liver or kidney failure) and even cancer. If you have a large breed dog, such as a Doberman or Great Dan, who's throwing up after drinking water this could mean a twisted stomach and is an emergency.
When should you be concerned about your dog throwing up?
If a dog throws up all the water that they drink, they will quickly become dehydrated. If they are not able to keep water down, they may need treatment to stop them from vomiting and sometimes fluids by a drip to rehydrate them. If your dog is not eating, losing weight, is dull and lethargic, or has abdominal (tummy) pain or bloating, this can indicate a more serious problem and you should contact a vet immediately.
Can tap water make my dog sick?
Water from unclean sources can contain bacteria and other infectious organisms that can make dogs (and people) sick. It’s important to give your dog clean, fresh, potable water, which is suitable for humans to drink too. Water that is not meant for humans to drink, or that is from muddy puddles, can cause illness. Stagnant water is particularly hazardous to your dog’s health and you should discourage them from swimming in or drinking from stagnant pools.
What can dogs drink other than water?
Dogs can drink special rehydration fluids, which can help them to get better after vomiting or diarrhoea. Some dogs are lactose intolerant, so dairy products are not recommended. Giving dogs flavoured water, such as chicken stock, can encourage them to drink, but these can contain high salt levels and so must be used with caution.