Updated April 13, 2021
Listen to this rubbish.
If your cat only eats dry food, she is likely to be getting less nutrition than a cat eating wet food. Many low-quality dry foods contain a lot of fillers.
Throwaway lines like these are typical of the overly simplistic advice you find online about feline nutrition. The truth takes a deeper look. To know whether wet, dry or both are best for your cat, we need to talk about:
- nutritional adequacy & completeness
- fillers in wet & dry cat food
- the risk of obesity
- diseases associated with wet & dry foods
- other alternative cat diets
Let’s dive in!
Complete vs Unbalanced Cat Foods
The main reason why the opening statement misses the point is that more than half of available wet foods are severely lacking in essential ingredients. I’ve listed Aussie examples here and shown you how to tell from the packaging. Therefore, while plenty of good, balanced wet foods exist, if you feed the others, your cat risks suffering a nutritional deficiency.
Dry diets, on the other hand, are almost always balanced for all essential nutrients. If you then feed an unbalanced wet food with these, it generally doesn’t matter so much. And yes, for nutritional completeness you can just feed a dry diet. But that still isn’t the whole story.
Fillers In Cat Food
Now let’s clear up some myths about fillers. By this, most people mean carbohydrates from grain sources. Here, three things are clearly true:
- High levels of carbohydrate in cat foods are not natural
- Despite this, most cats tolerate high levels of carbohydrate
- Many wet foods are as bad as dry foods
I have written before about the problematic levels of carbohydrate in cat foods, and I’m not going to make any excuses for the companies. However, despite being a vet who regularly trials sick cats on low carbohydrate diets, it’s actually rare that I get a positive response.
Similarly, there’s no evidence that high carb levels are by themselves dangerous to cats. And before going on, I want you to notice that most dry diets sold as grain-free have just swapped the carbs out for another source, such as sweet potato. This is marketing, not nutrition.
So let’s relax a bit about carbs. While not great, they’re mostly a minor evil. If you still want to feed a low carb diet, and why wouldn’t you, I’ve made a list of carbohydrate levels in Australian wet cat foods. There’s an online calculator you can use if your food isn’t listed.
Do Dry Foods Cause Obesity?
If you research the risk factors for feline obesity, you’ll find that dry foods don’t get a mention. So the answer is ‘no’. Instead, it’s much more important how you feed.
The reason dry foods get such a bad name is that they are so often left out for a cat to ‘graze’ on. This whole concept of free feeding is severely frowned upon by vets, because very few cats can be trusted to regulate their food intake.
Click here for advice on converting a free feeder to accepting timed regular meals. Once you do it, you’re at least three-quarters of the way to fixing feline obesity.
Disease Risks With Wet vs Dry Foods
There are only two evidence-based risks based on the food type.
Firstly, lower urinary tract disease in cats is more common on dry diets. These are the cats that get cystitis regularly, or have urinary obstructions. If a cat starts showing symptoms, I will always recommend a wet-only diet. However, as less than 5% of cats experience this problem, my opinion is that this advice doesn’t need to apply to all cats.
Dental disease, on the other hand, is more common on wet foods. However, the difference, while real, is small. Where it gets significant is when you choose the dry dental foods made by Hills or Royal Canin. These can be extremely effective in preventing tooth and gum disease.
Any other diseases you might read about are only in the author’s overly fertile imagination. That includes diabetes, liver, gastrointestinal and skin diseases. And in all the years of performing wellness blood testing, I have yet to find a healthy cat that’s dehydrated just from eating dry foods.
Alternatives To Commercial Cat Foods
What about following some of the advice that says you can make a raw diet for your cat instead?
When I read this I get very, very cross. Cats aren’t little dogs. There’s almost no way a normal person without specialised training and equipment can make a reliably balanced cat food.
You can either have a cat literally eating wild foods, or you have to accept the safety of manufactured cat foods. The only in-between might be found on my recipe for a wild-type cat diet which takes a bit from each. However, like all compromises, it won’t satisfy everyone.
So Are Wet Or Dry Diets Better?
The reality that for most cats, a 100% dry diet will be perfectly adequate, and no reason to feel guilty. I recommend spending as much as you can, as it’s clear that urinary problems go down as quality goes up. I also need you to understand feline water needs.
Dry foods are incredibly convenient, which is why I rely on one for my kitty (that’s him here). However he also gets cat grass, a raw chicken neck a day, and as you can see I keep his weight under control. All these factors increase my sense of security.
You may feel guilty and want to add a tasty wet food, and in theory that’s OK. My complaint is that when people who already choose a high quality dry get a wet food, it’s often a low quality one. That’s because wet foods need to be bought frequently, and so most people get them with their supermarket shop.
In the end, if the quality of your wet and dry cat foods are similar, it makes very little difference which one you choose.
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By Andrew Spanner BVSc(Hons) MVetStud, a vet in Adelaide, Australia. These articles are from a series regularly posted on email and Twitter. Subscribe via email here to never miss a story!