Should Cats Drink Softened Water?

The short answer to the title question is no, a cat should not drink softened water. However, this is not a black and white situation and I am yet to find a definitive answer regarding cats.

As for humans, in the UK, the British Water Code of Practice as referred to in the Water Supply (Water Fittings) Regulations, 1999 recommends that a mains water tap should be fitted that bypasses an ion-exchange water softener and which is supplied from mains water. Water from the mains in the UK meets very stringent standards and is often better than bottled water bought at the supermarket.

Cat drinking from tap. Photo by TBoard

As it is recommended that humans drink mains water rather then softened water, it is reasonable to presume that the same recommendation applies to companion animals. A point worth making is that cats get a lot of their water from their food if it is wet cat food. A low intake of tap water means it has less of an impact on their health.

Water softeners, that use salt, increase the amount of sodium in the water. The salt in ion exchange water softeners is used to regenerate the “ion exchange resin” in the device. This keeps the machine working. The ion exchange resin removes the minerals in the water that makes it hard: calcium and magnesium.

By how much is the sodium content of water increased by an ion exchange water softener? I’ll answer by referring to the daily recommended allowance of salt for humans in the UK. A litre of milk contains 25% of the daily allowance of sodium (salt equivalent of 1.5 grams). A litre of softened water contains 6% of the daily allowance. You can see that it is a small amount (0.35 grams equivalent of salt).

One important reason why an ion exchange water softener should be bypassed for drinking water is because powdered milk for babies has sodium in it already and to increase that level through softened water is bad for a baby’s health because they have a poor tolerance to sodium.

Although sodium is an important mineral for cats – it is used for muscle and nerve function – The American Society for the Prevention of Cruelty to Animals ® state that “foods that are inappropriate for pets” include salt. Salt is sodium chloride. I am not sure this is significant in relation to this article but it does confirm that salt in excess is not good.

As an ion exchange water softener uses salt and results in an increase in sodium in water it would seems wise and safe to plumb-in a bypass to the device that supplies tap (faucet) drinking water for your cat’s water bowl.

One final and important point, Elisa, a guest writer asks: Is water making your cat sick? This is about the contents of tap water that might not be good for your cat. The quality of tap water is dependent on where you are.

Click here to see a list of articles on water and cats.

References:

Department of the Environment, Food and Rural Affairs, London (Defra)
Department of Health, London
The Water Regulations Advisory Scheme, Oakdale, Gwent

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Comments

Should Cats Drink Softened Water? — 9 Comments

M E King on October 7, 2016 at 10:10 pm said:
Our well water is really hard. I even go to the laundry mat to wash clothes. I have a shampoo that demineralizes my hair. We don’t drink it and I would never let my house pets drink it either. It’s potable so we can bathe and wash dishes , brush teeth but we use bottled water for drinking and cooking.
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Diane Ricciardi Stewart on May 7, 2016 at 3:58 pm said:
Michael, I have a water fountain for my kitties. I do use a *PUR* water filter on my water use for consumption (mine, my son’s or my cats). This water is added to the water fountain which also has a charcoal filter. They love it so much!! I am forever re-filling the water! But I have 12 cats, so this is not unusual. They all drink plenty of water. I even have several that beg for cran-apple juice every day!! ♥♥♥
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marc on March 18, 2013 at 9:21 am said:
I use a water fountain with a charcoal filter which I guess softened the water for a while but I never changed it so I assume it is simply a gunk filter which prevents the pump getting blacked at this point. Tap water in Switzerland comes from the mountains and is considered to be much better quality than bottled water – not to mention the question of plastics and estrogen – so people here never buy bottled water because there is literally no point if you are getting spring water from your tap. I use a water fountain because the cats love to drink from it. A bowl just doesn’t do it even if you refill it 3 times a day, it’s not moving water and a cat is not really attracted to it. When I got my fountain they all started drinking from it regularly. They just walk past it and stop for a drink. They like the movement. I used to leave the tap on to get them to drink because the bowls weren’t working so well.
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- Michael on March 18, 2013 at 11:13 am said:
  Water Fountains? I like the idea of water fountains and bought one about 4 years ago but my lady cat wouldn’t use it so I chucked it out. Would you say that the downside is cleaning it to prevent mold build-up etc.?
  I think it is good to encourage cats to drink as it helps prevent urinary tract infections such as cystitis. Some cats are poor drinkers, Charlie is an example. I have only once seen him drink!
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  - marc on March 18, 2013 at 11:22 am said:
    No downside in my opinion. I can’t believe I never got one before recently. Every weekend I empty it and give everything a bit of a clean and refill it. In summer I tend to throw a few ice cubes in it and they seem to love the cold water on a hot day. No real downside. They all drink from it many times a day. I fill it up at least half a liter a day – they must drink close to half a liter between the 3 of them every 24hours. They love it when they are all our of breath from running around. Then they really gulp it down just like you or I would after physical exercise. For me the fountain was a real great thing I regret not having before. Its alot less work than washing a bowl and refilling it constantly. The fact that it’s moving makes them drink from it regularly. I see them. I watch Gigi walk past it and notice it and then decide to have a drink just like that. Very happy all around with it.
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Rowwdy on March 17, 2013 at 3:00 pm said:
Fortunately I have excellent well water. I test it regularly to make sure it hasn’t been contaminated. When I was in IL, the water was so bad, even I wouldn’t drink it. Hence, I didn’t allow my cats to drink it.
Michael; it sounds like the UK is better about water standards than the U.S. Our standards suck and there is always an excuse why the water is “temporarily” bad. Boil orders are not uncommon here.
As to soft water. It can be harmful to some pets. However, many tolerate plain tap water just fine. I think it is a “watch your pet” and see situation.
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Ruth aka Kattaddorra on March 17, 2013 at 1:20 pm said:
The cats we’ve had over 39 years have always drank tap water with no ill effect but just as we always run the cold water tap for a while before drinking any ourselves, we do the same when changing our cats water bowls.
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- Michael on March 17, 2013 at 2:12 pm said:
  What you’re doing is spot-on as far as I am concerned.
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Harvey Harrison on March 17, 2013 at 12:12 pm said:
Removing minerals from water is only useful for washing clothes or whn the minerals are very excessive for human or animal consumption. People and animals need this mineral s for health reasons. In the case of cats does the water contain an excess of minerals that can cause kidney or bladder problems? Although information as to what minerals may be the culprit I am told by my Vet that magnesium is the main culprit. I am annoyed to see the continued villainisation of sodium and salt. Salt does NOT cause high blood pressure. Salt reduction is only useful in lowering blood pressure after the damage has been done by other well-known factors. Throughout the Middle Ages the immense amount of salt used to preserve meat and fish did no harm at all, and in fact improved health and longevity by preventing food poisoning and enabling storage of otherwise perishable food. I doubt that cats in their original wild state would have consumed many minerals from the normal sources of water such as puddles or streams. Anyway, where would Felis s Lybica get water in the semi-desert habitat that it normally lives in? Perhaps from early morning dew which has no minerals, that’s all.
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