Signs of Dehydration in Dogs

​There are many causes of dehydration in dogs. Especially during hot weather, you may be concerned that your dog may not be drinking enough water. Dehydration, though, can happen any time of the year and may be caused by an illness that causes diarrhea, for instance. Dehydration in dogs is a fairly common occurrence, but it can be serious.

Side profile view of a fawn French Bulldog dog with long nose, sticking out tongue
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If you believe your dog is dehydrated, take him to the vet right away. In severe cases of dehydration, your dog may need water desperately but may not actually drink. Just encouraging your dog to drink water by placing the water bowl next to him might not be enough.

Your vet can examine your dog and help determine what caused the dehydration. They can also help you treat it at home and hopefully prevent the dehydration from reoccurring.

What causes dog dehydration

Dog can become dehydrated for many reasons, including illness. An overheated dog may need electrolytes to replace her fluid and salt balance. Dogs who eat only dry food can also become dehydrated, as canned food contains much more water than dry food. Make sure your dog has constant access to as much fresh water as they want.

The American Kennel Club says that an attack of vomiting can be enough to cause dehydration. Heat stroke, an illness that causes a fever, or being a senior dog can also be enough to cause dehydration. Watching your dog's behavior and knowing what's normal for them could be crucial in preventing dehydration.

Puppies or older dogs may not be able to moderate their water intake well enough. They may also be having so much fun exercising (running alongside you or playing catch) on a hot day that they pant too much and lose too much fluid.

Yellow Lab Smiling
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Signs of dog dehydration

The AKC says that signs of dehydration can range from slight to serious. Look for these possible warning signs:

  • Loss of skin elasticity - See the section below on checking for dog dehydration for information on how to determine if your dog's skin has lost elasticity.
  • Loss of appetite - Sometimes, even a lack of access to food can cause dehydration, according to the Humane Society. And then, your dog may not actually feel like eating even if they have food.
  • Vomiting with or without diarrhea
  • Reduced energy levels and lethargy
  • Panting - See note below about panting.
  • Sunken, dry-looking eyes - They should look shiny, like they normally do when your dog is healthy and happy.
  • Dry nose
  • Dry, sticky gums -
  • Thick saliva

Dogs do pant when they are tired or hot. But it is good to know what the difference is between normal and excessive panting. The Canna-Pet blog says 10 to 30 breaths a minute is normal. Since the normal rate of panting may vary based on the dog's breed and size, they recommend getting to know your dog's normal rate of panting so you can determine if something doesn't seem right.

How to check for dog dehydration

The Humane Society gives instructions for checking to see if your dog is dehydrated. As listed above, loss of skin elasticity is a sign of dog dehydration. The Humane Society suggests checking by pinching a little skin on your dog's back between your thumb and forefinger and then releasing it.

In a healthy dog, it should immediately sink back into place. If the tissue is dehydrated, it will sink back into place more slowly. They list this as an intermediate sign of dehydration.

Golden Retriever
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A secondary symptom to check for is "delayed capillary refill time." In this check, you firmly place your index finger against your dogs gums. Then push on the gums so that they appear white. Remove your finger and time how quickly the blood returns to the gums.

Do this when you know your dog is healthy so you have a baseline for your dog's capillary refill time. If you do this check and the gums return to their pink state in a time which is slower than normal, you may have a sign that your dog is dehydrated.