How Can I Treat My Dehydrated Cat at Home?

Author:
Mark dos Anjos, DVM
Updated:
Nov 20, 2023 6:58 PM EST

How do you hydrate a cat at home?
Photo by Petras Gagilas, CC BY-SA 2.0, via Flickr

"My cat (13) is losing weight very quickly and can't hold much water/food down. Is there a way to hydrate him without going to the vet?"—Grace

SQ Fluids Are Only Available With a Prescription

Although giving subcutaneous (SQ) fluids at home might increase both the quality and lifespan of your cat, there is no way in the U.S. to get access to these fluids without a prescription from your local veterinarian.

In the past, these fluids and drip sets were available from Costco, but they have decided not to carry this product anymore. Unfortunately, you can not get it from any health supply store without a prescription, either.

How to Keep Your Cat Comfortable at Home

Since you know that your cat is already dehydrated, there are things you can do that can help him be more comfortable:

Get Rid of Dry Food

I hope you have not made the mistake of purchasing this, despite recommendations from grocery stores, commercials, pet stores, and vet suppliers, as no cat needs this type of food at any stage of his life. (1)

I would say throw it away immediately, but you may need it for a while to get him to eat until he switches to a canned or homemade diet that he is willing to eat. Dry food causes subclinical dehydration even among young cats, and normal cats take almost all of their fluids in their food.

Dry food is dead food. It causes health problems, stresses the kidneys, and is particularly harmful to dehydrated cats whose health is already compromised.

Feed Only Wet Food

Whether you feed your cat moist canned food or a homemade diet, add as much water as possible. If your cat will not eat very wet food, you may need to reduce the amount of added water, but even a fresh chicken thigh contains about 75% water.

Make Water as Appealing as Possible

Buy multiple water bowls. Not all cats will seek out water, so you need to provide a bowl in the kitchen, in other rooms where he spends most of his time, in hallways, etc. Make sure the bowls are flat so as not to promote whisker fatigue.
Add an ice cube to the water bowl in the kitchen. Some cats like cold water, so as often as you go by the bowl, drop an ice cube into the water.
Buy a ceramic water fountain. If a cat is going to drink much at all, the water needs to be moving and not static (in the wild, still water is more likely to be poisoned). A fountain like the one sold at Amazon, above, is a good solution. The more water you can get your cat to drink, the better, (2) and this will also help your cat become less constipated.

Hydrate your cat with water from a syringe if he does not drink on his own.
Photo by Jon Haynes Photography, CC BY-ND 2.0, via Flickr

Why Is Your Cat Vomiting?

I am not sure about the cause of the vomiting and cannot tell without an exam and lab work. There are numerous causes for vomiting, and if you can afford to take your cat in before even starting these recommendations, it might do a lot of good.

Possible Causes

Kidney Disease: It may be something like kidney disease, where the toxins in the blood are causing the cat to be sick.
Simple Dehydration: If your cat drinks inadequate fluids, the colon becomes enlarged (megacolon) and stops functioning, which can cause vomiting.
Hyperthyroidism: Labwork may also indicate hyperthyroidism or another cause of vomiting.

If the results are normal and your cat just has a hairball, brushing him daily might help. Of course, no matter what the problem is, I still advise feeding moist food, never dry.

Last Resort: A Trip to the Vet

If none of this helps, and your cat continues to go downhill, there is not much you can do but take him to your local veterinarian and have him checked and put on IV fluids. The vet will do bloodwork at that same time to diagnose the severity of the kidney disease or find out issues that are causing the vomiting and dehydration.

References

(1) Buffington CA. Dry foods and risk of disease in cats. Can Vet J. 2008 Jun;49(6):561-3. PMID: 18624064; PMCID: PMC2387258. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2387258/
(2) Grant DC. Effect of water source on intake and urine concentration in healthy cats. J Feline Med Surg. 2010 Jun;12(6):431-4. doi: 10.1016/j.jfms.2009.10.008. Epub 2009 Dec 14. PMID: 20005758. http://pubmed.ncbi.nlm.nih.gov/20005758

This article is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from your veterinarian. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.