Dehydration in Dogs
Dog Health Guides · Lethargic or sick dog · Supportive care
Dog Dehydration: Signs, Simple Checks and What To Do
If you are reading about dog dehydration, your veterinarian is the best first step. This guide explains what owners commonly see and what to do next. It does not diagnose or prescribe.
Dog dehydration happens when a dog loses more fluid than it takes in, usually from vomiting, diarrhea, heat, fever, or not drinking. Mild dehydration can be corrected at home with water. Moderate or severe dehydration needs fluids from a vet.
Puppies, small dogs, seniors, and dogs with kidney disease or diabetes become dehydrated faster. This guide shows the simple gum and skin checks you can do tonight and when to go to the vet.
Important: Go to a vet now if your dog has dry, sticky or pale gums with sunken eyes, is weak or collapsing, keeps vomiting so it cannot hold water down, may have heatstroke, or has not urinated for a day.
See the bigger picture
This guide is part of our lethargic or sick dog guide, which covers related causes and when to call the vet.
What Dehydration Is
Fluid and Salts Lost
The body loses water and salts (electrolytes) that the heart, kidneys and muscles need to work properly.
A Sign of Something Else
Dehydration is almost always caused by another problem, such as vomiting, diarrhea, heat or illness, that also needs attention.
Why Speed Matters
Severe dehydration can damage the kidneys and lead to shock, especially in small or young dogs.
Signs of Dehydration in Dogs
Gums
Dry, sticky or tacky gums instead of wet and slippery. Press a gum until it turns pale: color should return within about two seconds.
Skin Tent Test
Gently lift the skin between the shoulder blades. It should spring back at once. Skin that stays tented or returns slowly suggests dehydration (less reliable in older and very lean dogs).
Eyes and Energy
Sunken or dull eyes, low energy, and a dry nose with thick saliva.
Urine
Less urine than normal, or dark yellow urine.
Common Causes of Dehydration in Dogs
Vomiting and Diarrhea
The most common causes. See dog vomiting and dog diarrhea.
Heat and Exercise
Hot days, hot cars, and hard exercise without water. Heatstroke is an emergency.
Not Drinking
Nausea, mouth pain, fever or general illness can stop a dog drinking. See lethargic dog.
Illness
Kidney disease, diabetes and liver problems can make dogs lose more fluid than normal.
What To Do Tonight
Mild
Slightly tacky gums but bright and drinking: small amounts of water often, rest, and recheck. Call your vet if it does not improve.
Urgent
Dry or pale gums, sunken eyes, weakness, repeated vomiting, heatstroke, or no urine: go to a vet now.
Related Dog Health Guides
Back to Dog Health Guides →Dehydration in Dogs FAQ
How can I tell if my dog is dehydrated?
Check for dry, sticky gums, slow gum color return, skin that stays tented when lifted, sunken eyes, low energy and dark urine.
How can I rehydrate my dog at home?
For mild cases, offer small amounts of water often and let your dog rest somewhere cool. If your dog cannot keep water down or seems weak, your vet needs to give fluids.
Can I give my dog an electrolyte drink?
Only if your vet recommends one. Some human drinks contain sugar or xylitol, which can be dangerous for dogs.
How long can a dog go without water?
Dogs should never go without water. A dog that refuses to drink for most of a day, or sooner if it is hot, young or sick, needs a vet.
Is dehydration in dogs an emergency?
Severe dehydration is. Weakness, dry or pale gums, sunken eyes or collapse need a vet straight away.
Is this dehydration in dogs guide a substitute for a vet visit?
No. It is educational only. Your veterinarian should examine your dog and guide any diagnosis and treatment.
Can I work out a medicine dose from this page?
No. Never work out doses from product strengths, other pets’ medicines or internet pages. The right medicine and dose depend on your dog’s weight, age, breed, health and other medicines, so they must come from your veterinarian.