Seeing your dog being sick and drinking lots of water can be alarming. Vomiting combined with excessive thirst may point to issues ranging from dehydration and gastrointestinal upset to more serious health concerns like kidney disease or diabetes.
These symptoms should never be brushed off as minor, because they may signal your dog is struggling to maintain balance in their body.
We outline the common reasons why a dog being sick and drinking lots of water may happen, what you can do at home, and when to seek veterinary help.
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Dog Being Sick and Drinking Lots of Water — Why It Happens
A dog being sick and drinking lots of water often happens because vomiting leads to dehydration, making the dog instinctively try to replace lost fluids. However, it can also signal underlying problems such as kidney disease, diabetes, Cushing’s disease, infections, or poisoning.
Excessive water intake together with vomiting should never be ignored, as it may indicate a serious health issue requiring veterinary attention.
Dog Being Sick and Drinking Lots of Water: Common Causes
Gastroenteritis
Gastroenteritis is one of the most common reasons a dog may vomit and drink excessively.
This condition involves inflammation of the stomach and intestines, often caused by spoiled food, dietary indiscretion, or infections.
The vomiting leads to fluid loss, which makes dogs very thirsty as their body tries to replace lost hydration. You may notice diarrhea, loss of appetite, or lethargy alongside the vomiting.
While mild cases sometimes resolve with rest and careful feeding, repeated vomiting or refusal to eat signals a more serious problem.
Read more: Dog Being Sick and Eating Grass (When to be concerned)
Dehydration
When a dog vomits, they quickly lose both fluids and electrolytes. This imbalance pushes them to drink more water than usual in an attempt to rehydrate.
Dehydration can develop fast, especially in smaller breeds, older dogs, or those with underlying health conditions.
Signs include dry gums, sunken eyes, skin that doesn’t bounce back when pinched, and extreme lethargy.
While drinking water is a natural response, vomiting may prevent them from keeping it down, worsening the cycle.
Pancreatitis
Pancreatitis occurs when the pancreas becomes inflamed, often triggered by fatty meals, dietary indiscretion, or metabolic conditions.
Dogs with pancreatitis often vomit repeatedly, appear hunched in pain, and may drink more water as their body tries to flush out toxins.
Pancreatitis can be life-threatening if untreated, leading to dehydration, systemic illness, and even organ failure.
It’s especially common in breeds like Miniature Schnauzers and Yorkshire Terriers but can occur in any dog.
Kidney Disease
Kidney problems can cause both vomiting and excessive drinking. Diseased kidneys lose their ability to filter waste products, leading to a buildup of toxins in the blood, which can trigger nausea and vomiting.
At the same time, the kidneys struggle to concentrate urine, so dogs urinate more and become increasingly thirsty.
If your dog seems weak, has bad breath with a chemical odor, or shows weight loss along with vomiting and thirst, kidney disease could be the cause.
Diabetes Mellitus
Diabetes can also explain why a dog vomits and drinks excessively. In diabetic dogs, sugar levels remain too high because insulin is not properly regulating glucose.
The excess sugar spills into the urine, pulling water with it, which causes intense thirst. At the same time, high sugar levels and complications like diabetic ketoacidosis may lead to nausea and vomiting.
Left untreated, diabetes is life-threatening, but with management, many dogs live happily for years.
Liver Disease
The liver plays a key role in detoxifying the body and aiding digestion. When the liver is compromised, toxins build up in the bloodstream, causing nausea, vomiting, and loss of appetite.
Dogs with liver disease often drink more to compensate for the imbalance, and you might notice yellowing of the gums, eyes, or skin (jaundice).
Because liver disease can progress silently before becoming severe, vomiting and thirst should always be investigated quickly.
What to Do If Your Dog Is Being Sick and Drinking Lots of Water
If your dog is vomiting and drinking excessively, the first step is to assess how severe the situation is. Offer small amounts of fresh water frequently rather than large amounts at once, which could trigger further vomiting.
Avoid giving food until their stomach settles, then reintroduce bland options like boiled chicken and rice in tiny portions. Keep them rested and watch closely for improvement.
It’s important to avoid home remedies unless directed by your vet, as certain over-the-counter medications are unsafe for dogs.
Keep your dog in a calm environment, and if vomiting persists or worsens, contact your vet promptly. For mild cases, short-term monitoring at home is okay, but repeated vomiting or refusal to drink should never be ignored.
When to Call or Visit Your Vet
You should seek veterinary attention immediately if your dog cannot keep water down, vomits multiple times in a day, or shows additional symptoms like diarrhea, weakness, or collapse. Blood in the vomit or stool, black tarry stools, or a bloated abdomen are all red flags.
Excessive drinking alongside vomiting can signal serious conditions like kidney failure, diabetes, or pancreatitis.
If your dog has a history of chronic illness or is very young, old, or frail, don’t delay in contacting your vet. They may need blood tests, imaging, or IV fluids to restore balance and address the root cause.
Read more: Dog Being Sick and Shaking (What this could mean)
Key Takeaway
A dog being sick and drinking lots of water is more than just a passing stomach upset. It may signal anything from gastroenteritis and dehydration to diabetes or kidney disease.
While some mild cases resolve with supportive care, persistent vomiting and excessive thirst are clear signs your dog needs veterinary attention.
Acting quickly ensures your dog gets the help they need and prevents complications. Always trust your instincts—if you’re worried, a call to your vet is the safest step.