Dehydration in dogs is more common than many pet parents realise—and if left untreated, it can lead to serious health issues. As a canine nutritionist, I often see hydration overlooked in conversations about dog health, even though water is one of the most vital nutrients your dog needs to thrive.
In this comprehensive guide, you’ll learn how to tell if your dog is dehydrated, the most common causes, how to treat it safely, when to seek veterinary help, and how to prevent dehydration in the future. Whether you feed raw, kibble, cooked meals or a mix, understanding your dog’s hydration status is crucial.

Why Hydration Matters for Dogs

Water is essential for every cellular process in your dog’s body—from regulating temperature and maintaining organ function, to aiding digestion and nutrient absorption. Dogs are approximately 60% water by body weight, and even mild dehydration can negatively affect their health and behaviour.

What does water do in your dog’s body?

Transports nutrients and oxygen
Flushes out toxins
Lubricates joints
Regulates body temperature
Supports digestion and elimination
Protects organs and tissues

How to Tell If Your Dog Is Dehydrated

Dehydration occurs when your dog loses more fluids than they take in, leading to an imbalance that affects cellular and organ function. Here are the key clinical and behavioural signs to watch for.

1. Loss of Skin Elasticity (Skin Turgor Test)

Gently lift the skin at the back of your dog’s neck or between their shoulder blades. In a well-hydrated dog, the skin will snap back quickly. If the skin stays tented or returns slowly, it’s a sign of dehydration.

Note: This test can be unreliable in older dogs or those with loose skin breeds (e.g., Shar Peis), so should be used alongside other signs.

2. Sticky or Dry Gums

A hydrated dog’s gums should be moist and slick. If the gums feel sticky, tacky, or dry to the touch, it may indicate fluid loss.

3. Sunken Eyes

Dogs suffering from moderate to severe dehydration may have eyes that appear dull, dry, or sunken into the sockets.

4. Lethargy and Weakness

A dehydrated dog may seem tired, slow to respond, or show a lack of interest in activities they usually enjoy.

5. Loss of Appetite

Dehydration can lead to nausea and a loss of appetite. If your dog skips meals and displays other signs, hydration should be assessed.

6. Panting and Overheating

While panting is normal, excessive panting (especially when it’s not hot) can indicate your dog is trying to cool down due to water imbalance.

7. Thick Saliva or Dry Nose

A dry nose or thick, ropey saliva can indicate a lack of sufficient moisture in the body.

8. Reduced Urination or Dark Yellow Urine

If your dog is urinating less frequently or their urine is dark and concentrated, they may not be taking in enough water.

Common Causes of Dehydration in Dogs

Understanding why dogs become dehydrated can help you prevent it. Here are the most common triggers:

Insufficient Water Intake

Dogs may drink less due to illness, stress, travel, unfamiliar bowls, or changes in routine or environment.

Hot Weather or Excessive Exercise

Dogs lose water quickly through panting. Warm weather, especially combined with vigorous activity, can lead to dehydration and even heatstroke.

Illness or Fever

Infections, high fevers, and systemic illnesses increase fluid loss and decrease a dog’s desire to eat or drink.

Vomiting and Diarrhoea

Acute or chronic gastrointestinal upset is one of the fastest ways dogs lose water and electrolytes.

Chronic Conditions

Dogs with kidney disease, diabetes, Addison’s disease, or cancer may struggle to maintain hydration due to increased urination or fluid losses.

Medications

Some medications such as diuretics or corticosteroids can increase fluid loss through urine.

Breeds at Higher Risk of Dehydration

While any dog can become dehydrated, certain breeds and groups are more vulnerable:

Brachycephalic breeds (e.g., Pugs, Bulldogs) – prone to overheating and poor temperature regulation
Senior dogs – reduced thirst drive and chronic conditions are common
Puppies – small body size and fast metabolism mean they dehydrate faster
Working/sporting dogs – higher fluid losses through exertion

At-Home Rehydration Tips

If your dog is showing signs of mild dehydration, you can often manage it at home. For moderate to severe dehydration, seek veterinary help immediately—especially if your dog is vomiting, has diarrhoea, or appears very lethargic.

Encourage Frequent Sips of Water
Don’t force large volumes at once. Offer small amounts frequently to avoid vomiting.
Add Water to Food
Mix warm water, bone broth (low sodium), or goat's milk into meals to encourage fluid intake.
Offer Hydrating Treats
Frozen watermelon, cucumber, or ice cubes made from bone broth can entice drinking.
Use Rehydration Solutions
Dog-safe electrolyte powders (e.g., Rebound, Oralade) may help replenish both fluids and electrolytes.
Syringe Water Slowly
If your dog refuses to drink, you can use a syringe to slowly drip water along the side of the mouth—but only if your dog is alert.

When to See a Vet

If your dog shows any of the following signs, don’t wait—get veterinary help:

Severe lethargy or collapse
Persistent vomiting or diarrhoea
Refusal to drink for more than 12 hours
Pale or dry gums
Unresponsiveness
Increased heart rate or laboured breathing

Your vet may administer subcutaneous or intravenous fluids depending on the severity and underlying cause.

How Much Water Should a Dog Drink?

As a general guideline, your dog should drink 50-60ml of water per kg of body weight per day.

Dog’s Weight Minimum Daily Water Intake;

5 kg 250–300 ml

10 kg 500–600 ml

20 kg 1–1.2 litres

30 kg 1.5–1.8 litres

This need can double in hot weather, with exercise, lactation, or illness.

Does Diet Affect Hydration?

Absolutely. Diet has a major impact on your dog’s overall fluid balance but it is important to remember that kibble dry food doesn’t mean your dog is dehydrated

Dry Food (Kibble)

Contains only 6–10% moisture
Dogs drinking more on kibble is normal and not a sign of dehydration (just compensating for the lack of water in food)
Still, owners should monitor intake and ensure constant access to water

Raw or Home-Cooked Food

65–80% moisture depending on ingredients
Dogs may appear to drink less—but they're often getting fluids directly from their food
You still need to ensure they drink on top of their meals, especially in warm weather

Wet or Canned Food

Typically 75–85% moisture
Ideal for dogs with low thirst drive or chronic kidney disease

Preventing Dehydration in Dogs

Fresh Water Always

Keep bowls clean and refill multiple times daily. Use ceramic or stainless steel—plastic can hold odours.

Add Moisture to Meals

Even if you feed kibble, you can:

Add a small amount of warm water or low-sodium broth
Add wet food, cooked toppers, or cooked vegetables
Use moisture-rich toppers like pumpkin or boiled meat juices

Monitor Intake

Use a measuring jug or a smart water bowl to track how much your dog drinks per day.

Travel Prepared

Always bring water and a collapsible bowl on walks, hikes, or car journeys.

Offer Variety

Some dogs prefer moving water—try a pet water fountain. Others like their water cold, so try adding ice cubes.

Hydration Boosters

Safe options include:

Bone broth (homemade or unsalted)
Coconut water (small amounts, no added sugar)
Commercial electrolyte solutions for dogs

Final Thoughts

Dehydration in dogs can range from mild and manageable to life-threatening. By learning how to spot the signs early and understanding your dog’s unique needs, you can take proactive steps to keep them hydrated and healthy.

Whether you’re feeding a dry, raw, or home-cooked diet, hydration is just as important as protein, fat, and vitamins. If you’re ever in doubt, always consult your vet or a qualified canine nutritionist.

References

National Research Council (2006). Nutrient Requirements of Dogs and Cats.
Zentek, J. et al. (2015). Water intake in dogs – influence of diet and clinical implications. Tierarztliche Praxis
Case, L. P. (2014). Canine and Feline Nutrition: A Resource for Companion Animal Professionals.
Baldwin, K. et al. (2010). Evaluation of hydration in dogs using mucous membrane moisture and capillary refill time. Journal of the American Animal Hospital Association.

Want to check if your dog’s diet is meeting their needs? Complete the FREE DIET ASSESSMENT HERE or book a consultation online now

Looking for more canine health and nutrition tips?

Subscribe to our newsletter and get expert advice delivered straight to your inbox!

How to Tell If Your Dog Is Dehydrated: Signs, Causes, and What to Do