A dog that suddenly stops eating but continues to drink water can be confusing and concerning, especially when they otherwise seem alert.
This pattern often means something is upsetting your dog’s stomach, mouth, or internal balance without yet fully affecting hydration.
In this guide, we explain the reasons why a dog may suddenly not eat but drink water, what to do and when to seek veterinary care.
Dog Suddenly Not Eating But Drinking Water: Why It Happens
A dog suddenly not eating but drinking water is usually experiencing nausea, dental discomfort, infection, organ stress, or early illness that suppresses appetite while thirst remains normal or increased.
Dogs will often keep drinking even when food feels unpleasant or painful to eat. Mild dehydration, fever, and toxin exposure can also increase thirst while reducing hunger.
Because appetite is often the first thing to change, this pattern can be an early warning sign.
Dog Suddenly Not Eating But Drinking Water: Common Causes
Nausea or Mild Digestive Upset
When a dog’s stomach or intestines are irritated, eating can make nausea worse. This causes dogs to avoid food while still wanting to drink to soothe the stomach.
Inflammation in the gut triggers signals in the brain that reduce appetite but do not necessarily stop thirst. Drinking water can actually feel calming when the stomach feels unsettled.
You may notice lip licking, swallowing, grass eating, or turning away from food but going to the water bowl.
This is one of the most common reasons a dog suddenly not eating but drinking water occurs, especially after diet changes or eating something unusual.
Related: Dog Suddenly Not Eating and Vomiting (Why it happens)
Dental or Mouth Pain
Dogs with sore teeth, gum disease, broken teeth, or mouth ulcers may avoid chewing but still drink without discomfort.
Dry kibble requires biting and grinding, which can be painful. Water flows past the teeth and gums with little pressure.
You may see drooling, pawing at the mouth, bad breath, or dropping food while chewing.
This makes dental disease a very common hidden cause of a dog suddenly not eating but drinking water.
Infection
Infections increase body temperature and cause muscle aches, fatigue, and loss of appetite.
Fever makes dogs feel hot and thirsty, so they drink more water while refusing food.
You may also notice shivering, warm ears, nasal discharge, or lethargy.
Because infections can spread quickly, a dog suddenly not eating but drinking water should be monitored closely for worsening symptoms.
Kidney or Liver Stress
The kidneys and liver remove toxins from the blood. When these organs are stressed or failing, waste products build up and cause nausea.
Nausea suppresses appetite, while kidney issues often increase thirst as the body tries to flush toxins.
You may see increased urination, weight loss, or vomiting.
Organ disease is a serious cause of a dog suddenly not eating but drinking water.
Pain
Any type of pain, including joint pain, abdominal pain, or internal injury, can reduce appetite.
Pain releases stress hormones that suppress hunger but do not reduce thirst. Your dog may still move, drink, and interact normally while refusing meals.
This makes pain an important cause of a dog suddenly not eating but drinking water.
Toxin Exposure
Some toxins irritate the stomach or affect organs, causing nausea and thirst at the same time.
Your dog may drink more water in an attempt to relieve discomfort or flush the system.
You may notice vomiting, drooling, or weakness.
This is a dangerous cause of a dog suddenly not eating but drinking water and requires veterinary attention.
Read more: Dog sick not eating and or drinking (Causes explained)
Dog Suddenly Not Eating But Drinking Water: What to Do
When your dog is suddenly not eating but drinking water, offer small amounts of bland food like boiled chicken and rice to see if appetite returns.
Make sure fresh water is always available so dehydration does not develop.
Avoid giving treats or table food that could make nausea worse. Watch closely for vomiting, diarrhea, or changes in behavior.
When to Call or Visit Your Vet
If your dog refuses food for more than 24 to 48 hours, contact your veterinarian.
Seek veterinary care if there is vomiting, diarrhea, weight loss, or lethargy.
A dog suddenly not eating but drinking water along with excessive thirst or urination should be evaluated. If poisoning is suspected, seek emergency help immediately.
Read more: Dog Shaking And Not Eating (What it means)
Key Takeaway
A dog suddenly not eating but drinking water is often an early sign of nausea, pain, or illness. While it can sometimes be mild, it should never be ignored.
By monitoring closely and involving your veterinarian when needed, you can protect your dog’s health and catch problems early.