When a dog is drinking a lot of water and not eating and throwing up, it’s a clear indication that something isn’t right with their health.
While a single episode may not be alarming, persistent vomiting combined with lack of appetite and excessive water intake can signal a serious underlying issue.
Understanding the causes is crucial so you can know what steps to take and when to seek help from a veterinarian.
Dog Drinking A Lot Of Water and Not Eating and Throwing Up: Why It Happens
This concerning combination of symptoms often signals an underlying health issue that affects your dog’s digestive system, metabolism, or overall well-being.
Common causes include gastrointestinal infections, dietary indiscretion, pancreatitis, kidney disease, liver disease, diabetes, toxin ingestion, side effects of medication, and stress or anxiety.
These conditions can disrupt normal appetite and hydration balance, triggering nausea, excessive thirst, and vomiting as the body struggles to cope.
Dog Drinking A Lot Of Water and Not Eating and Throwing Up: Common Causes
Gastrointestinal infections
One of the most common causes of a dog drinking a lot of water and not eating and throwing up is a gastrointestinal infection.
Bacteria, viruses, or parasites can irritate the stomach and intestines, leading to vomiting, nausea, and refusal to eat.
When a dog vomits repeatedly, they lose fluids, which in turn causes them to feel thirstier.
To rehydrate, they instinctively drink more water, but drinking too quickly or in large amounts can result in further vomiting, creating a vicious cycle.
Parvovirus, salmonella, and giardia are some of the pathogens that can cause these symptoms.
These infections are especially dangerous in puppies and senior dogs.
Related: Dog drinking a lot of water and not eating (Causes and when to worry)
Dietary indiscretion or food intolerance
Dogs are curious by nature and sometimes ingest food or substances that they shouldn’t.
Spoiled food, trash, greasy table scraps, or unfamiliar treats can cause stomach upset.
Food intolerance or sensitivity can also lead to vomiting, inappetence, and increased thirst.
For example, a dog may react badly to a sudden change in diet or certain ingredients like dairy, grains, or artificial preservatives.
When their digestive system is overwhelmed, vomiting may follow, and they may avoid eating altogether.
In such cases, dogs may try to compensate for their discomfort or dehydration by drinking more water, which unfortunately can worsen the vomiting if the stomach is irritated.
Pancreatitis
Pancreatitis is the inflammation of the pancreas and can cause symptoms such as vomiting, abdominal pain, lack of appetite, and excessive drinking. Fatty meals are a common trigger.
When a dog has pancreatitis, the digestive enzymes begin to attack the pancreas itself, causing significant pain and nausea.
As a result, the dog stops eating, and vomiting begins. Increased water intake may be due to fluid loss or the body’s attempt to cope with inflammation.
This condition requires veterinary care and can be life-threatening if not treated promptly.
Kidney disease
Chronic kidney disease in dogs can manifest with signs such as vomiting, drinking a lot of water, and not eating.
As the kidneys lose their ability to filter waste, toxins accumulate in the bloodstream, leading to nausea and reduced appetite.
Increased thirst happens because the kidneys are less efficient at conserving water, causing the dog to urinate more and feel dehydrated.
Vomiting may also be a result of uremic toxins affecting the stomach lining.
Older dogs are especially prone to kidney issues, and these symptoms should prompt immediate veterinary evaluation.
Liver disease
Liver problems can also result in a dog drinking a lot of water and not eating and throwing up. The liver plays a crucial role in detoxification, digestion, and metabolism.
When it isn’t functioning properly, toxins build up, causing gastrointestinal symptoms like nausea and vomiting.
Increased water intake may happen due to changes in blood chemistry or dehydration from vomiting.
You may also notice other signs such as yellowing of the eyes or gums (jaundice), lethargy, or weight loss.
Diabetes
Diabetes in dogs often presents with increased thirst and urination, loss of appetite, and vomiting.
Dogs with uncontrolled diabetes may develop a serious condition called diabetic ketoacidosis, which causes vomiting, dehydration, and lethargy.
As the blood sugar becomes dangerously high, dogs stop eating and start vomiting due to the metabolic imbalance.
Drinking more water is a response to dehydration and excess glucose in the urine.
This condition requires emergency veterinary care.
Ingestion of toxins or foreign bodies
If your dog ingested a toxic substance—such as chocolate, grapes, xylitol, certain plants, or household chemicals—they may start vomiting and refuse food.
Many toxins also cause increased thirst due to kidney or liver involvement.
Similarly, if a dog swallows a foreign object like a sock or bone fragment, it can cause an obstruction in the digestive tract.
Vomiting may be the first sign, followed by refusal to eat and increased water intake as the body becomes stressed and dehydrated.
Side effects of medication
Some medications can lead to a dog drinking a lot of water and not eating and throwing up.
Drugs like anti-inflammatories, antibiotics, or chemotherapy medications may upset the stomach or cause nausea.
Steroids, for instance, can lead to increased thirst and urination while also irritating the gastrointestinal system.
If you suspect your dog is reacting poorly to a new medication, consult your vet immediately.
Stress and anxiety
Stress is another factor that may lead to your dog drinking a lot of water and not eating and throwing up.
Dogs under stress might experience an upset stomach, resulting in vomiting and reduced appetite.
Stress also triggers increased panting and dehydration, which leads to increased water intake.
Major changes like moving to a new home, the introduction of a new pet, or loud noises such as fireworks can trigger this chain of symptoms.
Signs of stress include pacing, hiding, drooling, yawning, or clingy behavior.
What to do
If your dog shows these symptoms, here are the steps to take:
1. Stop food for a short period
Withhold food for 12–24 hours to allow your dog’s stomach to settle.
However, ensure access to small amounts of clean water to prevent dehydration.
If vomiting continues despite fasting, do not delay veterinary attention.
2. Offer bland food after vomiting stops
Once the vomiting subsides, gradually reintroduce a bland diet such as boiled chicken and white rice in small amounts.
Monitor closely to see if symptoms return.
3. Avoid giving medication without veterinary advice
Don’t give over-the-counter medications or leftovers from previous prescriptions.
Many human drugs are toxic to dogs and can worsen their condition.
4. Keep your dog hydrated
If your dog cannot keep water down or continues vomiting after drinking, seek immediate veterinary help.
Dehydration can become serious quickly, especially in puppies or senior dogs.
5. Observe additional symptoms
Look for warning signs like blood in vomit, black stool, pale gums, bloating, or collapse.
These may indicate life-threatening conditions such as internal bleeding or gastric torsion (bloat).
6. Visit a veterinarian immediately if:
Vomiting persists for more than 24 hours
Your dog shows signs of pain or lethargy
There is blood in vomit or stool
Your dog refuses water
Your dog is a puppy, elderly, or has a chronic condition
Early intervention can prevent complications and save your dog’s life.
Key Takeaway
A dog drinking a lot of water and not eating and throwing up is a clear signal that something is wrong.
While isolated vomiting may be harmless, when combined with loss of appetite and excessive thirst, it could point to infections, organ dysfunction, poisoning, or other serious illnesses.
Prompt veterinary care is crucial. Monitor your dog’s symptoms carefully, avoid risky home treatments, and provide supportive care such as hydration and rest.
Your timely response can make all the difference in your dog’s recovery and overall well-being.