Why Cats Don’t Do Carbs: The Truth About Feline Amylase

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A simplified look at feline digestion — highlighting the stomach and intestines, where enzymes like amylase (or the lack thereof) shape how cats process food.

The Curious Case of Jaspurr’s Stomach

Jaspurr ("Chaos in fur"), my Bengal Cat. He is about one year-old and typically full of life.

I was supposed to write a post about the cat microbiome last week, but, my Bengal cat Jaspurr had other plans. He got sick, and after a few frantic clean-ups and too many vet calls, I realized his wet food might have been the culprit. Thankfully, he’s feeling better now — and true to my inner science nerd self, I went down a rabbit hole (or should I say cat tunnel?) researching the feline proteome to understand what could cause food intolerance in cats.

Now, let’s be clear: I’m not a vet or a biochemist. I’ve been a pet parent for nearly two decades, but my first baby was actually a dog named Honey Badger. I do have a PhD in microbiology — which mostly means that when I dove into the scientific literature on feline digestion, there was… a lot to digest (pun intended).

If you have a Bengal, you probably know that their stomachs can be as dramatic as their personalities — prone to sensitivities, Inflammatory Bowel Disease (IBD), and even pancreatitis. Phew! Meanwhile, my other cat, Purrl, seems to have an iron stomach. If she were human, her ideal diet would be an all-inclusive burger-fries-cookies buffet (and yes, she would demand dessert).

So why is Jaspurr so different? That’s where my inner scientist took over — and led me to one fascinating enzyme that might explain it all: amylase.

Amylase in Cats

My own cartoon interpretation of the crystallized amylase enzyme. If you’re a biochemist, please don’t panic — I know it’s not to scale! Because sometimes science just needs a little style...

Amylase is an enzyme — a type of protein that acts like a microscopic pair of scissors, cutting up starches (complex carbohydrates) into smaller sugar molecules like glucose. In most mammals, amylase starts working as soon as food hits the mouth, helping digest bread, rice, or other carbs.

Amylase is produced primarily in the pancreas and saliva of most mammals — like humans and dogs (the "omnivores"). But cats, being obligate carnivores, produce very little amylase — which means starch isn’t their strong suit.

Small capacity for starch digestion.

When it comes to carbs, cats just aren’t that impressed. Their digestive systems have a limited ability to break down starch — no matter how fancy the kibble looks.

Multiple reviews agree cats have a limited endogenous capacity to digest starch. They can use some processed carbohydrates, but their enzymatic toolkit is modest.

Grain-Free Doesn’t Mean Low-Starch

Although “grain-free” diets are increasingly popular, they are not necessarily low in carbohydrates. These formulations often substitute grains with other starch-rich ingredients such as legumes or root vegetables (e.g., potato, sweet potato), which can result in comparable or higher starch content than traditional grain-based foods.

What Are Resistant Starches — and Why Cats Might Still Need Some

Resistant starches are starches that are not digested and not absorbed. They eventually pass on to the lower digestive tract where they act as dietary fibers, which are closely related to gut health.

Cats May Not Have a Sweet Tooth but They Still Need Carbs

Even though cats can’t taste sweetness and don’t crave sugar, glucose and other carbohydrates still play essential roles in their biology. Glucose is required for the synthesis of nucleic acids (like DNA and RNA), certain amino acids and glycoproteins, and even vitamin C. It also fuels specialized cells such as those in the brain, eyes, and blood.

Pancreas does the heavy lifting.

Pancreas Power! Since cats don’t make much salivary amylase, their pancreas does most of the starch-digesting work — though still not as much as in dogs or humans.

Cats rely on pancreatic amylase (not salivary) to break down starch; overall intestinal carbohydrase activity is low compared with many species.

When cats eat more carbs than their enzymes can handle, the extra starch doesn’t get absorbed as glucose. It travels to the colon, where bacteria have a little feast of their own — sometimes leaving your cat with the not-so-fun aftermath of fermentation.

Poor Jaspurr — his gut definitely didn’t appreciate that experiment.

Processing matters.

Processing matters! Heat and cooking can make starches easier for cats to digest — though it doesn’t turn them into carb-loving creatures overnight.

Reviews note cats can utilize carbohydrates when properly processed (e.g., gelatinized/heat-treated), which makes starch more accessible to pancreatic amylase—even though absolute enzyme activity is modest.

Glycemic “chill.”

Glycemic chill achieved. Unlike humans or dogs, cats show only tiny glucose spikes after eating — their metabolism stays cool, calm, and carnivore.

Compared with dogs and humans, cats often show low or negligible post-prandial glucose/insulin responses to different starch sources (when tested as ingredients), reflecting their carnivore metabolism.

Why the difference with dogs?

Different evolutionary paths: dogs adapted to starch-rich diets alongside humans, while cats stayed true to their carnivorous roots.

Comparative genetics links high dog amylase activity to selection for starch-rich diets alongside humans; ancient-DNA and breed studies show this repeatedly. Cats, as obligate carnivores with different domestication ecology, did not follow that path.

Dog vs. cat: copy-number story

Dogs have multiple copies of the AMY2B gene for amylase production — cats only one. Evolution clearly had different dinner plans for them.

During dog evolution, the AMY2B (pancreatic amylase) gene underwent copy-number expansions, boosting amylase activity and starch tolerance. This surge is not reported in cats, helping explain species differences.

Emerging saliva science.

Saliva science is catching up! Some studies suggest cats might have measurable salivary amylase — not for digestion, but as a potential stress biomarker. (And no, we’re not collecting spit samples at home… yet.)

Beyond digestion, saliva is becoming a hot diagnostic fluid in veterinary medicine. A recent feline sAA paper fits a broader trend of salivary biomarkers for non-invasive screening, including the detection of infectious diseases, allergies and dental disease.

No salivary amylase… or is there?

No salivary amylase… or is there? Recent studies suggest cats might have some — but only as a stress marker, not for digestion. (And no, I’m definitely not recommending you stress your cat to test that theory!)

Classic teaching says cats don’t make salivary amylase—the starch-starter enzyme many omnivores have.

Update: a 2025 peer-reviewed study analytically validated measuring salivary α-amylase in cats and showed it rises with acute stress and in some urinary tract diseases, suggesting sAA could be a non-invasive stress biomarker for cats. (It’s not about starch digestion per se, but detection in saliva.)

Tried, Tested, and Cat-Approved: Jaspurr’s Digestive Essentials

These are the products that helped soothe Jaspurr’s sensitive stomach and keep his digestion happy (every cat is different, so please check with your veterinarian for any health questions).

Tap or click the pictures in the scroll gallery below to shop my favorite cleaning products without leaving the page.

• Nutramax Proviable®: I now use this high-quality probiotic + prebiotic health supplement blend developed by veterinarians. It contains multiple beneficial bacterial strains, plus prebiotics that help those good microbes thrive. It’s suitable for both cats and dogs, which is a huge plus for multi-pet households.

• Purina FortiFlora Probiotics for Cats: When Jaspurr’s tummy acts up, this is my go-to. It helps restore balance to his gut microbiome and keeps things running smoothly (pun intended). I sprinkle it over his wet food — he loves the taste, and I love the peace of mind.

• Optimeal Grain-Free Wet Cat Food Pouches: Soft, gentle, and easy to digest — perfect for sensitive cats. I like that this brand includes natural antioxidants and omega fatty acids for coat health. I appreciate that this brand uses primarily European-sourced ingredients, which tend to follow stricter regulations on genetically modified crops. It’s grain-free but not carb-crazy, which makes both my inner scientist and Jaspurr’s stomach happy.

• Instinct Raw Boost Mixers – Digestive Health: A little sprinkle of this freeze-dried topper turns any meal into a probiotic-powered feast. It contains pumpkin, sweet potato, and probiotics to support digestion. Bonus: even picky Jaspurr thinks it’s a treat.

• Weruva Pumpkin Patch Up! Pumpkin is a miracle ingredient for cats with sensitive stomachs — rich in fiber and naturally soothing. I mix half a pouch with steamed chicken whenever digestion needs a gentle nudge. Think of it as the feline version of a cozy autumn soup — just skip the pumpkin spices, or you’ll be in for a *very* smelly trick. 🎃

• Large Disposable Litter Boxes for Cats: These are a lifesaver. I added extra boxes in every single room to help prevent accidents. They’re open top (easy reach when Jaspurr had to... ugh... "run") and made of sturdy recycled paper that’s surprisingly durable and absorbent. Bonus: they are cute and help control odor — and Jaspurr hasn’t managed to destroy one yet.

• Cat Litter Trash Can – Mini Countertop Bin: Perfect for quick cleanups and small spaces. The press-lid design keeps odors contained (and curious paws out). I keep one next to every litter box for easy maintenance — chic and functional.

• Cat Litter Scoop Kit – Stainless Steel Mesh Scooper: This scoop makes daily cleaning oddly satisfying. The fine mesh catches clumps without wasting litter, and the holder keeps things tidy. A small design upgrade that makes a big difference.

• Mrs. Meyer’s Clean Day – Pet Multi-Surface Cleaner: Because clean shouldn’t mean chemical overload. This plant-based formula cuts through messes and leaves a light orange-blossom scent. Safe for pet areas and gentle on my own hands — win-win.

• Mrs. Meyer’s Clean Day – Pet Stain & Odor Fighter: For those inevitable “oops” moments, this spray is my go-to. It lifts stains, neutralizes odors, and makes the house smell fresh without harsh chemicals. Even Purrl approves (and she’s picky about everything).