An interesting study1 clearly states that the addition of Xylitol to the drinking water of cats was effective in reducing plaque and calculus in their mouths. You know that plaque and calculus builds up in the mouths of cats along the gum line and is a major cause of gum disease. Gum disease is a major health issue in domestic cats, and it often leads to the necessity to seek veterinary treatment which can lead to a general anaesthetic for teeth cleaning which in turn carries risks of brain damage or death. So, you can see how interested I am in ways to reduce the build-up of plaque and calculus.
But are there health dangers to adding Xylitol to cat drinking water? On the Internet, you will see some warnings about the dangers of Xylitol, but they concern dogs on my research.
Xylitol is a natural sugar alcohol found in plants, fruits and vegetables. It tastes sweet to humans (but cats can’t taste it?) but it doesn’t cause tooth decay. In fact, it reduces the levels of decay-causing bacteria in saliva. It also acts against some bacteria which cause ear infections. In products for humans, you will find it in sugar-free chewing gums, mints and sweets.
In the US product manufacturers are allowed to state that Xylitol in their products reduces the risk of tooth cavities. And humans also use it to reduce tooth plaque, ear infections and dry mouth. Although they say there is no scientific evidence to support these kinds of uses.
However, to return to the study that I mention in the first paragraph, there is scientific evidence to support the fact that it reduces plaque and calculus in cats. Therefore, you could argue quite convincingly that it does the same for humans.
The big warning, as mentioned, is that it is toxic to dogs and if a dog eats a product that contains Xylitol, they should be taken to a veterinarian immediately.
For the sake of complete clarity, I’m going to ask whether Xylitol is toxic to cats. And fortunately, I can rely on another study to find the answer. It is called: Effects of p.o. administered xylitol in cats.
Rather dangerously I would argue, they dissolved Xylitol in deionised water in various concentrations: 100, 500 and 1,000 mg/kg body weight of the cats. These doses would have been considered toxic to dogs and they might even have caused death in dogs. However, in cats they state, “Based on our results, xylitol did not induce toxic effects on cats”.
They state that there were no significant changes in any of the haematological or biochemical parameters in cats and that blood glucose concentrations “did not show any significant alterations except at 1000 mg per kilogram dose where a mild but significant increase was observed but it was in physiological range”.
Conclusion: I think it is worth considering WITH VETERINARY ADVICE adding Xylitol in low concentrations to cat drinking water in order to help protect the cat against a build-up of calculus and plaque on their teeth. I think it needs further research but please don’t do anything without speaking to your veterinarian first. Although I am relying on solid scientific evidence.
1. The study referred to: Drinking Water Additive Decreases Plaque and Calculus Accumulation in Cats.
RELATED: Can cats drink seawater? Yes and no!
Cats drinking water in general
Separately, and on a different but related topic, there are discussions on the Internet as to whether cats who are poor drinkers of water are more likely to drink from a glass bowl or even a glass tumbler if they can get their head into it! Some can and do which belies the theory that cats don’t like their whiskers touching the sides of a bowl when eating or drinking.
There is anecdotal evidence which points to cats preferring drinking water from glass receptacles. There are two possible reasons. Firstly, glass looks like water and therefore the water might look more natural to them and instinctively they drink from it. Secondly, glass is more neutral and benign than plastic, for example. Plastic will probably taint the taste of water. The same may occur with metal bowls. Ceramic bowls will be good. Cats are very sensitive to the taste of water and sometimes prefer drinking from muddy puddles to fresh tap water containing chlorine.
If my cat wasn’t drinking water well (and please note that domestic cats are not good drinkers in any case because of their wildcat inheritance) I would provide a glass bowl and place it away from the food bowl to see whether that improved drinking behaviour. Although cats get a lot of their moisture from their food which means that they should eat wet cat food as a default.
Below are some more pages on water.