Why is My Dog Drinking a Lot of Water but Not Eating?

Introduction: When to Worry About Changes in Drinking and Eating

As a loving dog owner, you know your dog’s daily routine by heart. You know when they eat, when they play, and when they nap. So, when you notice a big change—like your dog suddenly drinking a lot more water than usual while also refusing to eat—it can be very concerning. This is a very common issue, but it can also be a sign of a serious medical problem that needs your attention right away. This guide will help you understand why your dog might be showing these signs, what you can do at home, and when you need to call the vet immediately. Acting fast can make all the difference for your best friend.

Understanding Normal Drinking and Eating Habits in Dogs

Before you worry, it helps to understand what is considered normal for a dog. This will help you know if your dog’s behavior is a real problem or just a small change.

How Much Water Dogs Usually Drink

A general rule of thumb is that a healthy dog needs about one ounce of water per pound of body weight each day. This can change a lot depending on their size, how active they are, and the weather. For example, a 50-pound dog should drink about 50 ounces of water in a day. If your dog is drinking much more than that filling their bowl multiple times a day or needing to go outside more often it’s a sign of a condition called polydipsia, or increased thirst.

Normal Eating Patterns in Healthy Dogs

Most dogs have a pretty regular eating schedule. They usually eat once or twice a day and finish their meals with gusto. A loss of appetite, or anorexia, is when a dog refuses to eat or eats much less than normal. If this lasts for more than a day or two, it’s a sign that something is wrong.

Medical Reasons Why Dogs Drink More Water but Refuse Food

When a dog is drinking a lot but not eating, it’s often a sign that a bigger medical issue is at play. The combination of these two symptoms can point to some very specific health conditions.

Kidney Disease

The kidneys are vital organs that act as a filter, removing toxins and waste from the blood. As a dog gets older, their kidneys can stop working as well. When the kidneys can’t do their job, the dog’s body tries to flush out the toxins by drinking a lot more water. This is why increased thirst is often the first sign of kidney disease. The buildup of toxins can also make the dog feel very sick to their stomach, which causes them to lose their appetite.

Diabetes Mellitus

Diabetes happens when a dog’s body can’t properly use or create insulin. Insulin is needed to turn sugar from food into energy. When a dog has diabetes, the sugar stays in their blood instead of going into their cells. The dog’s body tries to get rid of all this extra sugar by making the dog urinate more. To make up for the water they are losing through urination, the dog gets very thirsty and drinks a lot. Even though they are getting plenty of sugar from food, their body can’t use it, so they are constantly hungry. But in some cases, they can also feel sick and not want to eat, especially in the early stages.

Cushing’s Disease (Hyperadrenocorticism)

Cushing’s disease is a condition where a dog’s body makes too much of a hormone called cortisol. This hormone can cause a lot of problems, including making the dog drink a lot more water. The high levels of cortisol can also lead to muscle weakness and a loss of appetite. Other signs of Cushing’s disease include a pot-bellied appearance, hair loss, and a thinning of the skin.

Liver Disease

The liver is another important organ that helps to filter blood and digest food. When a dog has liver disease, it can affect their appetite and make them feel sick. The liver also plays a role in keeping the dog’s body hydrated, so problems with the liver can also lead to increased thirst. Other signs of liver problems can include vomiting, diarrhea, and a yellow tint to the skin or eyes.

Urinary Tract Infections (UTIs)

A urinary tract infection is a common problem in dogs. An infection can cause a dog to drink more water to help flush out the bacteria. The pain and discomfort from the infection can also make them feel unwell and lose their appetite. If your dog is also urinating more often or having accidents in the house, a UTI could be the cause.

Fever and Infections

Just like in people, a fever or infection can make a dog feel unwell. A fever will cause a dog to become dehydrated, which makes them very thirsty.²⁰ The general feeling of being sick can make them not want to eat.

Cancer in Senior Dogs

As dogs get older, the risk of cancer goes up. A tumor or cancer can cause many problems in a dog’s body. They can often cause a dog to feel sick to their stomach, leading to a loss of appetite. A dog’s body may also try to fight the cancer, and this can lead to dehydration and increased thirst.

Non-Medical Reasons for Increased Thirst and Loss of Appetite

While these symptoms are often a sign of a serious medical issue, sometimes the cause is not as severe. It’s still important to pay attention to these things.

Stress or Anxiety

Just like people, dogs can lose their appetite when they are stressed or anxious. If you’ve recently moved, a new person has come into the house, or your dog is scared of something, they might not want to eat. They may drink more water as a way to deal with the stress.

Medication Side Effects

If your dog has recently started a new medicine, a side effect of the medicine could be making them feel unwell. Talk to your vet about the medicine and its side effects. Some medicines, like steroids, are known to cause a dog to drink a lot more water than usual.

Environmental Factors (Heat, Exercise, Weather)

If it’s a very hot day, or if your dog has been exercising a lot, it is normal for them to drink more water. They will also feel tired and might not want to eat as much. Make sure to keep your dog cool and always give them fresh water.

Warning Signs That Need Immediate Vet Attention

While some causes are not an emergency, some are. If you see any of the following signs, you need to get your dog to the vet immediately.

Severe Dehydration

If your dog is not getting enough water, they can become dehydrated very quickly. You can check for dehydration by gently pulling up the skin on their neck or back. If it snaps back quickly, they are fine. If it stays tented, they are dehydrated.

Vomiting and Diarrhea

If your dog is vomiting or has diarrhea along with drinking a lot and not eating, they are losing a lot of fluids and can become dehydrated very quickly. This is a very serious sign.

Weakness, Collapse, or Seizures

If your dog seems very weak, is having trouble standing, or has collapsed, this is a sign that something is very wrong with their body. Seizures are also a serious sign that you need to get to the vet right away.

What You Should Do if Your Dog is Drinking but Not Eating

If you notice your dog is showing these symptoms, here is a step-by-step guide on what to do.

Step 1: Monitor Closely

Watch your dog and see what they are doing. How much water are they really drinking? How many times are they going to the bathroom? What other signs do you see, like vomiting or weakness? Write it all down so you can give your vet as much information as possible.

Step 2: Offer Bland Diet Options

Sometimes a dog won’t eat because of a stomach upset.³¹ You can try to offer them a bland diet of boiled chicken and white rice. If they still refuse to eat it, you know the problem is likely not a simple one.

Step 3: Ensure Fresh Water Access

Even though your dog is drinking a lot, it is very important to make sure they always have fresh, clean water. Do not try to limit their water intake. This can make the problem worse and cause a serious problem with dehydration.

Step 4: Call Your Veterinarian

This is the most important step. Tell your vet everything you have observed. Your vet will know if the symptoms are a sign of a serious illness and can tell you what to do next. It is always better to be safe than sorry.

How Vets Diagnose the Cause

When you take your dog to the vet, they will do a few things to figure out what is wrong.

Physical Exams

Your vet will do a full physical exam. They will check your dog’s gums for signs of dehydration, feel their belly for any pain, and listen to their heart and lungs.³²

Blood Tests and Urine Tests

A vet will almost always recommend blood work and a urine test. These tests can tell a vet a lot about what is going on inside your dog’s body. Blood work can show signs of kidney or liver disease, diabetes, or an infection. A urine test can show if your dog has an infection or if their kidneys are not working properly.³³

Imaging (X-rays or Ultrasound)

Your vet may want to take an X-ray or do an ultrasound to get a better look at your dog’s organs, like their kidneys, liver, or bladder. This can help them find a problem like a tumor or a bladder stone.

Treatment Options Based on Diagnosis

The treatment for your dog will depend on what the vet finds.

Managing Kidney and Liver Issues

If your dog has kidney or liver disease, the vet will likely recommend a special diet to help their body manage the problem.³⁴ They may also give them medicine to help with the symptoms.

Treating Diabetes and Cushing’s Disease

For diabetes, your dog will likely need daily insulin shots.³⁵ Your vet will teach you how to give the shots and will help you manage your dog’s diet and care. For Cushing’s disease, a dog will need medicine to help control the level of the hormone in their body.³⁶

Antibiotics for Infections

If your dog has an infection, like a UTI, your vet will give them antibiotics to fight the infection.³⁷ Your dog should start to feel better in just a few days.

Supportive Care for Senior Dogs

For older dogs with serious or chronic conditions, the treatment will be to help manage their symptoms and keep them comfortable. This may include special diets, medicine, and extra care at home.

Preventing Future Eating and Drinking Problems

The best way to keep your dog healthy is to take good care of them and to be proactive.

Regular Vet Check-Ups

As your dog gets older, they should see the vet at least twice a year. This helps the vet catch any problems early, before they become serious.

Balanced Diet for Senior Dogs

Feeding your dog a healthy, balanced diet made just for seniors can help prevent many health problems.

Hydration Tips

Always make sure your dog has fresh, clean water. You can also add some wet food to their diet to help with their hydration.³⁸

FAQs About Dogs Drinking But Not Eating

Should I limit my dog’s water?

No. Never limit your dog’s water. If they are drinking a lot, it’s a sign that their body needs it. Limiting their water can cause a serious problem with dehydration.

Could my dog just be a picky eater?

While some dogs are picky, a complete refusal to eat, especially along with increased thirst, is usually a sign of a medical problem.

What is the normal amount of water for a dog?

It is about one ounce of water per pound of body weight each day.39 So a 20-pound dog should drink about 20 ounces of water a day.40

What is the difference between increased thirst and increased urination?

They often go together. A dog might drink a lot of water because they are urinating a lot, or they might urinate a lot because they are drinking a lot. Both can be a sign of a serious problem.

Conclusion: Acting Fast Can Save Your Dog’s Life

Watching your dog drink a lot of water while not eating can be a scary thing. While the cause can be simple, it can also be a sign of a serious illness that needs to be treated right away. By knowing the signs, acting quickly, and working with your veterinarian, you can find the cause of the problem and help your best friend get back to feeling like themselves again. Your loving care and attention to these symptoms can make a world of difference for your dog’s health and happiness.