Signs of Dehydration in Dogs and Cats (How to Check at Home)
Quick Answer
Three quick at-home tests to check dehydration in dogs and cats, the warning signs that need a vet immediately, and how to safely rehydrate at home. Vet-reviewed.
Key Takeaways
- A 5% dehydrated pet is mildly off; 10% is in trouble; 15% is dying.
- Three at-home tests: skin tent, gum capillary refill, eye sunkenness.
- Cats hide dehydration extremely well; by the time they look dehydrated they often are 8-10%+.
- Puppies, kittens, and seniors decompensate within hours of moderate dehydration.
Photo: Manja Vitolic / Unsplash
Why dehydration matters fast
This guide walks through three at-home tests, the warning signs that need a vet immediately, and how to safely rehydrate at home for mild cases.
Three at-home dehydration tests
1. Skin tent test
2. Gum check (capillary refill time)
3. Eye check
Warning signs that need a vet immediately
- Lethargy + not interested in water
- Vomiting + diarrhea simultaneously
- Won't drink for >12 hours (especially cats)
- Pale or dry gums
- Sunken eyes
- Excessive panting in cool environment
- Loss of skin elasticity (skin tent stays >3 seconds)
- Puppy or kitten with any signs (they decompensate in hours)
Common causes of dehydration
- Heat exposure (especially flat-faced breeds)
- Vomiting and diarrhea
- Kidney disease (especially in older cats)
- Diabetes
- Decreased water intake (fussy senior cats are common)
- Fever
- Burns
Daily water needs (rough guide)
- Dogs: 50-60 mL per kg body weight per day
- Cats: 50-60 mL per kg per day
- Wet food provides ~70-80% water; dry food <10%
- Cats fed wet food rarely drink much from the bowl, that's normal
Get a 3-question triage and a vet-reviewed action plan.
Free. 30 seconds. No credit card. iOS and Android.
How to safely rehydrate at home (mild cases only)
- Offer fresh water in small amounts every 30 minutes
- Pet electrolyte solution (Pedialyte unflavored is OK for dogs and cats in small amounts, ask vet)
- Ice cubes (some pets prefer to lick)
- Wet food or warm broth (low sodium, no onion or garlic)
- Cool environment, rest
- Vomiting after drinking
- No improvement in 2-4 hours
- Any worsening sign
When to NOT rehydrate at home
- Pet won't keep fluids down
- Severe dehydration signs
- Underlying chronic condition unmanaged
- Young puppy or kitten (always vet)
- Senior pet with kidney disease
Vets give IV or subcutaneous fluids that no home method can match.
Cat-specific notes
Cats hide dehydration extremely well, by the time they look dehydrated, they often are 8-10%+. Cats with chronic kidney disease can be chronically dehydrated for months. Subcutaneous fluid administration at home (taught by your vet) is the standard of care for CKD cats. If your cat has CKD, learn this skill.
Dog-specific notes
Brachycephalic breeds (Pug, Bulldog, French Bulldog, Boxer) overheat fast in summer. Carry water on walks. Avoid midday exercise.
The Omelo angle
Related reading
References
Get a 3-question triage and a vet-reviewed action plan.
Free. 30 seconds. No credit card. iOS and Android.
More in Vet Reviewed
Breed-Specific Health Guides
View all breed health guidesWas this article helpful?
Dr. Ashim Sarkar, BVSc & AH
Veterinarian · Medical Reviewer
Reviews all clinical and triage content on Omelo. Hands-on small-animal practice experience across vomiting, dermatology, vaccinations, and emergency triage. All Omelo recommendations pass through Dr. Sarkar before publication.
Read Dr. Sarkar's full bio →