Best Diet for Cats

Since I started practicing veterinary medicine 27 (gulp) years ago, a lot has changed.  One of the biggest changes that has come about in the last couple years is the diets recommended for cats.  I used to tell people that dry food was the best because it helped to clean the cat’s teeth… I find that it’s not really the case at all.  Feeding a canned , grain free diet may be the best thing to feed your cat.  Read on for more detailed information and a list of diets…

Dr.  Soule


High Protein/Low Carbohydrate (grain-free) Diets
Nutritionally speaking, cats are “obligate carnivores”.  This means they need very high levels of protein to thrive and don’t have a very good ability for utilizing carbohydrates (grains,sugars).  Cats also need some nutrients that can only be obtained from animal tissue, not plants.  By ancestry, cats are descendants of desert cats (African wild cat, F. lybica).  This is why they have very concentrated urine and a very low thirst drive.  In the wild, cats hunt primarily small rodents and birds as prey.  All these creatures are about 70% moisture.  This is how cats in the wild get most of their water requirements.

Now let’s think about what we typically feed our cats over their lifetime.  They usually get most of their food in the form of dry kibble.  Some people feed canned food but rarely exclusively.  this traditional way of feeding cats presents two major problems as discussed below:

First, most of the common brands of cat foods are full of carbohydrates in the form of grains (corn, rice, soy, wheat).  As “obligate carnivores”, cats aren’t designed to use high levels of carbohydrates for nutrition.  Cats specifically do not have the enzymes in their liver or saliva that are optimal to process carbohydrates.  Their mouths, teeth, digestive tracts, pancreas, and liver are specifically designed for a high protein diet.  So why are most pet food companies putting so many grains (carbohydrates) into cat food?  The answers could be many including convenience, larger profit margins, or the mistaken conception that cats are small dogs.  When reading the ingredient label on food, a meat source is usually listed first but this doesn’t mean the diet is high protein.  If the next several ingredients are a form of grain (listed above), this is a high carbohydrate food.  Plants do contain protein, but for an obligate carnivore like cats, this is a lower quality protein.  Animal based proteins have biologic values (a measure of usability) ranging from 100% (egg) to 78% (beef).  Plant based proteins range from 67% (soybean) to 45% (corn).

What does a carbohydrate loaded diet mean in the long run to your cat?  High carbohydrates can predispose to obesity, just like in people.  Diabetes is common in cats and high carbohydrate diets and obesity are known to be risk factors.  Obesity also leads to arthritis.  Add to this scenario the typical spoiled, well-loved cat that doesn’t have to “hunt for its food”, and you have a sedentary lifestyle that also increases the risk of obesity and diabetes.  It is known that a high carbohydrate diet actually changes the ph level and thus the bacterial types that grow in the mouth and digestive tracts.  This change in bacterial content can lead to intestinal problems in some cats.  Grains can be a source of allergies for some cats too.

The second problem a dry diet creates is a potentially dehydrated cat.  Wild cats get most of their moisture from the prey they eat (mouse =70% water).  The average dry food is only 10% water.  Most feline practitioners and internal medicine specialists are now recommending an exclusively canned diet since the moisture in canned food most closely mimics their natural prey.  It is thought that the lack of moisture in dry diets can contribute to urinary tract disease such as cystitis, crystals, and stones.

Many people have been told canned food is bad for teeth and can lead to dental disease.  This is only partially true.  Although canned food can leave more residue on the teeth than dry food, dry food does virtually nothing to help keep the teeth clean.  It would be the equivalent of your dentist telling you it is ok to eat crunchy cookies to help clean your teeth.  There are a few dental diets on the market that do a better job of scraping plaque off the teeth, but they are high carbohydrate and are only minimally effective at actual cleaning.  The real reason for dental disease is lack of dental care.  Obviously it is difficult to get a cat to accept daily tooth brushing, but there are some “cat friendly” options available.  Your veterinarian can advise you on these products.

**So what shouuld your cat eat for optimal health?  The more moisture your cat receives, the better.  If your cat loves canned food and you don’t mind feeding it exclusively, it is currently thought to be the best option as it mimics their moisture requirement.  Grain-free canned food is the lowest in carbohydrates.  If your cat refuses to eat canned food, the grain free dry foods are still the best option nutritionally.  Many cats will accept the dry food with water added.  It is imperative to have fresh water available at all times.

It is important to realize there is no such thing as the perfect pet food.  Changing brands every once and a while or mixing brands may help ensure your cat gets the best each company has to offer.  It is also good to offer variety so we don’t train our cats to become finicky eaters.  There are many grain free dry and canned foods on the market.  High protein levels may not be advisable for select medical conditions.  Please talk to your veterinarian regarding the recommendations for your cat.

Recommended Grain-free Foods:
(When making a diet change, mix old food with new and gradually transition to a new diet to prevent stomach upset.)

Canned Foods:

Brand                        kcal
Addiction                        *
AvoDerm                        *
Before Grain                    *
Best Feline Friend                    *
Blue Buffalo Wilderness                *
California Natural Salmon & Sweet Potato        *
Evanger’s                    *
Innova Evo                    *
Merrick Turducken                    *
Natural Balance LID Diets                *
Natural Planet Organics                *
Newman’s Own Grain Free                *
Pinnacle                        *
Wellness Core or Wellness Grain Free            *
Weruva                        *

*Most adult cats need about 200 calories (kcal) per 24 hours as a maintenance for ideal weight.  All canned foods range from 30-40 kcal per ounce with very little variance between brands.  If your cat is eating exclusively canned food (no dry), the ideal amount is equal to one 5.5oz (tuna can size) can per 24 hour period.

Dry Foods:

Brand                        kcal/cup
Taste of the Wild                    390
Before Grain                    406-409
California Natural Herring & Sweet Potato        418
Natural Balance LID Diets                449-452
Indigo Moon                    450
Innova Evo (Weight Management)            481
Wysong Epigen original                489
Felidae Grain Free                    498
Innova Evo (Heriring/Salmon)                530
Wellness Core                    536
Orijen                        540
Pinnacle                        562
Blue Buffalo Wilderness                587
Innova Evo (Turkey/Chicken)                602

Fancy Feast Low Carbohydrate Flavors

The following foods from Fancy Feast are not grain-free, but are considered lower carbohydrate (less than 10%) than most commercial foods and do not have any wheat gluten, which can be very allergenic.  These foods are available in most grocery stores.

Chopped Grill Feast
Flaked Fish* and Shrimp Feast
Flaked Ocean Fish* Feast
Gourmet Chicken Feast (this one looks very similar to another chicken variety that contains gluten)
Savory Salmon* Feast
Tender Beef & Chicken Feast
Tender Beef & Liver Feast
Tender Beef Feast
Tender Liver & Chicken Feast
Turkey & Gibblets Feast

*Remember that it is a good idea to limit serving fish to a few times a week.

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