I heard that cats can drink sea water and get hydrated (less thirsty). I have also heard that people can die from drinking sea water.

Can cats drink sea water and do well?

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    Where did you hear this? Salt is bad for cats as it imbalances their electrolytes. I don't know how salt in water makes it any less bad :/
    – Just Do It
    Dec 23, 2015 at 21:15
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  • The Wikipedia entry cites a couple of references... Rats also, apparently, have this ability.
    – Joanne C
    Dec 24, 2015 at 3:37
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    Given that kidney failure is a common cause of death in aging housecats, I would emphasize that "survive" does not mean "thrive" (do well) even if this statement is true. But it wouldn't completely survive me. Housecats are descended from a desert species; efficient water handling and ability to tolerate high salt levels would indeed be good adaptations for that environment.
    – keshlam
    Dec 24, 2015 at 17:29
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    @JohnCavan I looked at the references a bit, I am not sure how much actual support those references give for the statement on Wikipedia. Dec 25, 2015 at 2:16

2 Answers 2


Yes, cats can "drink" sea water. Anyone can for that matter can drink sea water. Is it good for them? No. Will they? Questionable. They will also not get hydrated from drinking sea water - the opposite will happen. Sea water contains high levels of Sodium and Chloride (mainly salt).

It is a well known fact that most domestic species, including companion animals, can tolerate high levels of salt in their diets (up to 13% is mentioned) - as long as there is fresh water available. If not, high levels of Sodium gets absorbed into the blood and has an osmotic effect, pulling water towards the blood, DEhydrating the body and increasing the blood pressure (similar to humans eating lots of salted meats). Cats are no different. Dehydration, as with any species, will lead to many other problems including blindness, renal shut down, seisures, etc, including death.

  • Source Merck Veterinary Manual (I used 10th edition). "Salt poisoning" under pathophysiology and etiology.

I think what some people might confuse cats and salt water with, and I recall, I can't quote at the moment, is the fact that, being desert animals, cats have huge capacity for retaining water in their bodies. Their kidneys can retain water and concentrate urine to excrete a concentrated mineral mixture. Evolutionary, this puts a lot of strain on their kidneys, making them more prone to renal functional problems which lead to partial or complete failure.

For this reason, veterinary feline diets often contains relative high levels of salt to stimulate (fresh) water intake, to better support the kidneys.


Cats can make urine with specific gravity of 1.050, or higher. 1.050 is about 7% sodium chloride (the majority of the solids in urine is NaCl).



The other answers here are noise; generic "Merck Veterinary Manual says too much salt in the diet is bad". That doesn't answer the question.

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    This does not answer the question. While I can see the relationship between specific gravity of urine and fluid intake, the answer only talks about urine. Sep 29, 2017 at 23:25

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