Why Your Cat Should Eat Canned Food

I wanted to write a blog about canned cat food since I go over this with owners on a daily basis.  If I could feed a cat the perfect, evolutionarily appropriate diet, it would be a squirrel/mouse/rat/etc in a can.  Since I have not seen these “novel proteins” over the counter (and I am saying that with some sarcasm), then we will have to make do with the canned options that are in front of us.  Nudge nudge, I think someone in the cat food business should consider supplying these “novel proteins” for cats, could be huge, just saying.

I have attached some links and research abstracts from PubMed as well, but it is important for me to state I AM NOT A BOARD CERTIFIED NUTRITIONIST.  I usually tell clients, cats are obligate carnivores, they need animal based protein in order to survive.  If they became vegetarian or vegan, they could suffer severe deficiencies, leading to death.  When looking at a can of cat food, make sure it states it is balanced, complete nutrition.  There are some “appetizers” or “supplemental only” foods on the shelves, so be careful.  The other major warning - CATS CAN STARVE THEMSELVES!!  A sudden decrease in calories could lead to a potentially fatal Hepatic Lipidosis (fatty liver syndrome), so if your cat refuses to transition to canned food, then discuss dry food options with your veterinarian.

As a carnivore, cats eat meat - PROTEIN and WATER.  


One of the articles at the end of the blog is an abstract regarding carbohydrate metabolism in a cat.  They process it differently.  In general, the overweight cats I see, are typically fed a free-choice dry cat food (carbs), available all day long.  This is usually the biggest issue.  My kitties are crunchy crazy and always beg for dry food, but I only give very small amounts.  I try to utilize cat food puzzles to make them “work” for their dry food.  Plus it helps with mental stimulation and gives them something to do.  I usually use the food puzzle right before bed, so they let me sleep a little longer before begging for food (so 5 am rather than 4 am).  I can go into much more detail regarding the wet food/dry food, but I usually have clients read more about it on their own.  http://catinfo.org/

MOISTURE CONTENT - I always have clients tell me “But my cat drinks water all the time!!!  So they don’t need more water.”  I remember going to a CE conference and a board certified nutritionist showing a video comparing how dogs drink water and how cats drink water.  Cats are really not made to slurp.  So they may be spending a lot of time at the water bowl, but they are making more of a splatter and drinking less water than you would think.  They only take in drop by drop.  Here is a cool slow motion video of a cat drinking:  https://www.youtube.com/watch?v=Fgf9y8mo414.  Cats need a lot of water for good urinary health.  This can make a huge impact on cystitis and kidney failure by making a simple change to canned food.

After hearing the above information, the next question clients ask me is “Well what should I feed my pet?”  This can be difficult.  Not all cats like canned food, so if they refuse it, talk to your veterinarian about other options, portions, etc.  I find that some cats have food allergies/sensitivities, so I tend to stay away from seafood based foods.  How many deep sea diving cats do you know that are catching tuna? Be sure to look at your label though, it may say “Turkey” but the third or fourth ingredient may be fish or chicken.  I am sure that we will find some future issues with processed cat food, just like we are finding with humans.  So I try to use tuna sparingly due to mercury levels and yellow fat syndrome.  Companies also probably use farm-raised fish, so there are inherent issues there with antibiotics/dioxins/etc, but how they apply to the cat is yet to be seen.  Chicken and other meats are processed in factories and subject to contamination and recalls, just like our food.  

“But dry food is good for their teeth!!”  I don’t see any dry food/crunchy treats out in the wild for feral cats, and their teeth may be fine.  Genetics and alignment of teeth play a big role in tartar accumulation. 

Overall, I would much rather see cats on a canned food to help with healthy weight, lean muscle mass, and improved urinary health.  This link goes over Protein/Fat/Carb percentages:


Just because the food is expensive, doesn’t mean it’s higher in protein, so take a look at this link and see what I mean.  There are some affordable, higher protein foods available at the grocery store if you know what to look for.

Please consult your veterinarian before making any changes to your cats diet.  My cats hated me at the beginning of the transition (which took a long time).  They would chew on my hair and bat things off counters, but eventually, they adjusted and now they beg for wet food.  

Dr. Leah Wulforst, Riverside Veterinary Clinic, Knoxville, TN




The domestic cat's wild ancestors are obligate carnivores that consume prey containing only minimal amounts of carbohydrates. Evolutionary events adapted the cat's metabolism and physiology to this diet strictly composed of animal tissues and led to unique digestive and metabolic peculiarities of carbohydrate metabolism. The domestic cat still closely resembles its wild ancestor. Although the carnivore connection of domestic cats is well recognised, little is known about the precise nutrient profile to which the digestive physiology and metabolism of the cat have adapted throughout evolution. Moreover, studies show that domestic cats balance macronutrient intake by selecting low-carbohydratefoods. The fact that cats evolved consuming low-carbohydrate prey has led to speculations that high-carbohydrate diets could be detrimental for a cat's health. More specifically, it has been suggested that excess carbohydrates could lead to feline obesity and diabetes mellitus. Additionally, the chances for remission of diabetes mellitus are higher in cats that consume a low-carbohydrate diet. This literature review will summarise current carbohydrate knowledge pertaining to digestion, absorption and metabolism of carbohydrates, food selection and macronutrient balancing in healthy, obese and diabetic cats, as well as the role of carbohydrates in prevention and treatment of obesity and diabetes mellitus.


Vagal unitary responses to intestinal amino acid infusions in the anesthetized cat: a putative signal for protein induced satiety.  Jeanningros R.  https://www.ncbi.nlm.nih.gov/pubmed/6281820


Single unitary discharges in the nodose ganglia were recorded extracellularly in chloralose anesthetized cats while amino acid solutions were being perfused through the small intestine via implanted cannulae. Test infusions consisted of either amino acid mixtures (12 amino acids; 120 mM in all) or individual amino acids (50 mM each) dissolved in Krebs Henseleit buffer. Units which were activated by amino acid infusions were also tested with 10% glucose infusions performed in the same way. Control infusions consisted of either buffer alone or a physiological saline solution isotonic to the test solution. All perfusions were performed at 38 degrees C, pH 7.4 by means of a syringe over a 10 second period. Out of 1250 vagal units activated by electrical vagal stimulation, 92 units showed an increased firing rate in response to amino acid intestinal perfusions. Of these, only 1/7 were also responsive to glucose perfusions. Osmotic, thermal or mechanical stimuli associated with infusions did not modify vagal responses to the amino acids. Among vagal units responding only to amino acid but not to glucose infusion, some were activated in a specific manner, depending on the specific amino acid infused intraduodenally. These neurons illustrated a very strict specificity regarding the nature of chemical stimuli. The very short latency, mean of 9 sec +/- 0.7 (SE) of these vagal neurons to amino acid infusions unequivocally indicates that chemoreceptors are located at the preabsorptive level. The corresponding fibers were non-myelinated (conduction velocities: 0.8/1.4 m/sec.) and were of the C type. The functional characteristics of these vagal amino acid receptors are discussed in terms of the role of intestinal signals in short term protein satiety.