Nutrition and Obesity in Senior Cats and Dogs

Nutrition and Obesity in Senior Cats and Dogs

In this article you will learn about the building blocks of nutrition, what a balanced diet means, how to create the ideal diet for your companion cat or dog (they have different needs), and the real reason our four-legged friends get chubby. (Hint: it applies to us too!)

There’s an old saying that people and their pets resemble each other. In many ways, this is unfortunate because the incidence of obesity in the feline and canine worlds has paralleled that of humans. In addition, the health problems associated with being overweight our companions can have are just as severe as ours.

We are going to look at the basics of feline and canine nutrition, learn that cats and dogs have different requirements, explore the usefulness of supplements, and find out what a Balanced Diet really means.

The Basics: What Essential Nutrients Do Our Pets Need?

There are 6 groups of nutrients that our pets (and we) need to sustain life. If we include dietary supplements, of which there are a number, we can stretch this list to 7.


Water is necessary for every function of our body. It is the basis of life as we know it on the earth and an abundant supply of fresh, filtered water is needed for our companion animals to thrive.


Protein is necessary for all aspects of growth and development. It is a vital constituent of every part of the body and is what makes up the mass of muscle. Protein is made up of building blocks called amino acids. There are 22 amino acids. Animals can make 12 of them within their bodies from other substances, but the remaining 10 must be supplied from their diet. The ones that must come from the diet are called essential amino acids. They are arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. In cats, taurine is also an essential amino acid. (Dogs can make taurine in their bodies, but cats cannot so it must be supplied in their food, hence the old saying that dogs can eat cat food, but cats cannot eat dog food.)

All Protein is Not Equal

The quality and digestibility of protein are both important. The highest quality protein is one that contains all of the amino acids AND is easily broken down, or digested by our pets. The biological value of a protein is a measure of its quality and digestibility. An egg is a protein of very high quality and is easily digested. It has been assigned a biological value of 1 and is the standard upon which other proteins are graded. The biological values of other proteins are as follows (the numbers are approximate): Fish meal and milk = 92, Beef = 78, Soybean meal = 67, Meat and bone meal = 50, and Corn = 45. Things like hair and feathers, which are used in some low-quality feeds, are very low in biological value because although they are high in protein they cannot be easily digested.


To simplify things very greatly, carbohydrates are sugar molecules strung together in long chains. Grains like wheat and rice are mostly carbohydrates. Carbohydrates are an important source of energy, however, diets very high in carbohydrates have been linked to obesity and diabetes (more about this later).


Fats are important for many functions of the body including the transports of certain substances in the blood, the structure of cell walls, and as a highly concentrated form of energy. They are also necessary for the absorption of fat-soluble vitamins. Fats, like amino acids, come in 2 forms. The body can make some fats from carbohydrates (this is one of the reasons that you get fat quickly from eating too many carbohydrates), and other fats have to be supplied in the diet because the body cannot make them. The ones that must be supplied are called essential fatty acids. Fats also make foods taste better-but we already knew this!


Minerals are needed for many of the regulatory functions of the body. Many hormones and enzymes need minerals to function properly. For example, blood cannot clot without calcium or carry oxygen without iron, and bones cannot develop without phosphorus. Macrominerals are those needed in relatively large amounts and are: calcium, phosphorus, potassium, sodium, and magnesium. Microminerals are those needed in relatively small amounts and are: iron, zinc, copper, manganese, iodine, cobalt, and selenium. The body cannot produce minerals so they all must be supplied in the diet.


Vitamins are chemicals that are needed so certain reactions in the body can occur. For example, without vitamin K blood would not clot because some of the reactions in the clotting process would not occur. Vitamins are important for thousands of different bodily processes and work in conjunction with minerals and enzymes.

Two Groups of Vitamins

Vitamins are divided into two groups. Fat-soluble vitamins are: A, D, E, and K. Water-soluble vitamins are: C, B1 (thiamin), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B12 (cyanocobalamin), folic acid, and biotin. Fat-soluble vitamins are stored in the body in the liver and fat so the body always has a constant reserve of them (assuming a well-balanced diet). Water-soluble vitamins are not stored in the body and must be part of the diet every day. Some vitamins can be made in the body; for instance, dogs can produce vitamin C, but people cannot.

The Importance of Vitamins

Each vitamin is important for specific functions. Vitamin A is important for skin and coat; D for bones and teeth; E is an antioxidant important for preventing cancers and heart problems; K keeps the blood healthy, C combats stress and is an antioxidant, and the B vitamins are important for muscle, skin, and blood.


Supplements is a term applied to a diverse group of substances that are used to give our body all of the nutrients and chemicals it needs to function at its best. We are going to discuss 2 specific supplements.


Enzymes are proteins that make other reactions happen. For example, amylase is an enzyme (a protein made up of a specific sequence of amino acids) found in the saliva of people and dogs that begins the breakdown of carbohydrates in foods when we chew them. (Cats do not have amylase in their saliva.) Enzymes are found throughout the body-in cells, organs, blood, secretions, and the digestive tract. Enzymes given as supplements assist the breakdown of food in the digestive tract so that their nutrients can be absorbed.


Probiotics are healthy bacteria. Our digestive tract is filled with many types of bacteria that help us digest food. (Cows are the best example of this. Without the bacteria that live in their digestive tract they would get absolutely NO nutrition from grass and could not live!) Illness or simply aging can reduce the amount of healthy bacteria in our animals’ digestive tract. Probiotics replace these missing, healthy organisms.

Nutrition and Obesity in Senior Cats and Dogs

Controversy Over Animal Nutrition

The field of animal nutrition, just like human nutrition, is filled to the brim with controversy. Are supplements necessary or not? Raw or cooked food? Home-cooked food or prepared food? Kibbles or chunks? Meat or grain-based? Natural or engineered? Premium, high protein, or standard? You get the idea. Unfortunately, if you gather 10 experts together you are likely to get 10 different opinions. So what are you to do?


You are taking the first step by educating yourself with articles like this. Second, realize that there is more than one way to feed your companion that is going to provide them with all the nutrition they need to live a long and healthy life. Third, recognize your companion’s unique needs. A 4-year old Border Collie who herds sheep every day will have many different dietary requirements than a 12-year old Poodle who accompanies you for walks through the backyard twice a day.

Pet Food Labels: What’s Wrong with Corn?

Reading food labels is an art unto itself. While we are not going to review the meaning of everything printed on a label, there are a couple of points that are important to keep in mind.


The most important thing to know is that the label lists ingredients by weight in the order of most to least. This means the first ingredient listed is the one with the highest weight percentage in the food. If you read the label and corn are listed as the first ingredient, that food contains more corn by weight than any other ingredient. Unfortunately, most medium and low-end commercial foods have corn as the first ingredient because corn is incredibly cheap. These corn-based foods either do not supply enough protein, or the ratio of carbohydrates to protein is too high. Also, be aware of a trick many manufactures play known as ingredient splitting. Splitting means that corn can be added to feed in different forms and each of these forms can be listed separately on the label. While corn may not be the first ingredient listed, it still may be the most plentiful in the food. Consequently, caution must still be used even if the first ingredient listed is beef, lamb, or some other form of protein. Examine the label of a national dry dog food brand below:

Beef and bone meal, ground wheat, brewers rice, corn gluten meal, ground yellow corn, beef tallow preserved with mixed tocopherols (source of vitamin E), soybean meal, animal digest, salt, potassium chloride, L-Lysine monohydrochloride, choline chloride, zinc sulfate, ferrous sulfate, vitamin supplements (A, E, B-12, D-3), DL-Methionine, manganese sulfate, niacin, calcium carbonate, brewers dried yeast, copper sulfate, calcium pantothenate, garlic oil, pyridoxine hydrochloride, thiamine mononitrate, riboflavin supplement, calcium iodate, menadione sodium bisulfite complex (source of vitamin K activity), folic acid, biotin, sodium selenite.

Notice that the first ingredient is a meat and bone meal, but 5 of the next 6 are grains. In the book, Food Pets Die For: Shocking Facts About Pet Food, Ann Martin explains, “Most people reading this label might assume that the first ingredient listed is the prime ingredient providing an ample source of protein…” however, “…to make it appear that a protein source is the number one ingredient in the food, the company splits the corn up into two categories; corn gluten meal and ground yellow corn.

Am I Feeding My Cat or Dog a Balanced Diet?

In a nutshell, a balanced diet is one where all of the essential nutrients are present in adequate amounts and correct ratios.


The idea of the correct ratio is important. For example, adding a calcium supplement with the idea that it will make stronger bones may actually be harmful if not enough phosphorous is available so the body can use the calcium. In general, a dog should receive about 25% to 40% of their calories from protein, 40% to 50% from carbohydrates, and 10% to 15% from fat. Cats are different (see below) and should receive 35% to 45% of their calories from protein, 40% from fat, and only a small amount from carbohydrates. Working dogs should have an increased percentage of protein and fat in their diet.

Protein and Age

For a time it was believed that as an animal aged its protein requirements decreased. At present, most experts believe that older animals should have the same percentage of protein in their diet as when they were younger, but the total calories should be reduced by 20% to 30%.

Why Cats and Dogs Need Different Diets?

Cats are Carnivores

Cats are true carnivores and wild felines consume a diet of primarily meat protein and fat. In fact, cats have difficulty metabolizing carbohydrates (remember, no amylase in their saliva) and a diet high in carbohydrates, such as with dry cat kibble, increases their risk of obesity and diabetes. (It’s been said by some experts in the field that a mouse a day provides a balanced and complete diet for a cat!) Dry cat kibble can be problematic for our felines in other ways as well. Feeding dry kibble can over time lead to cats being in a state of perpetual dehydration. Cats have not evolved to “drink” extra water to make up for a lack of moisture in their diet. This is believed to be a contributing factor in the development of Chronic Renal Failure and Urinary Tract Disease.

Dogs are Omnivores

Dogs are omnivores, which means dogs can readily digest both meats and grains. To say this a different way, cats cannot live unless they consume some meat. There are many other metabolic differences between cats and dogs, but you get the idea: cats and dogs have different nutritional needs!

What Type of Food Is Best For My Pet?

Raw Food

Raw diets are generally considered best, and this includes raw meats, veggies and fruits. Despite popular belief, properly prepared fresh raw meat does not pose any health hazards to humans or our four-legged friends. Simply use the same precautions preparing raw food for your pets as you do handling your own raw meats. When animals are started young most will eagerly consume raw foods. Older animals may find a raw meat diet less appealing. This is mainly due to either their diminished sense of smell, or them being accustomed to the fat, preservatives, and fillers in commercial junk food.

Home Cooked

Home-cooked is a wonderful second choice and allows our companions a generous variety of foods-can you imagine eating the same prepared, out of the bag or canned food for years? What we typically call table food falls into this category. In general, what we eat (okay, we are going to leave potato chips out of this conversation) is good for our animals and is higher quality than most commercial food. Problems arise for our pets, as for us, if balance is not there-too much carbohydrate, too little protein, or too much fat. Processed foods loaded with sodium, dyes, and preservative are not good choices for us and shouldn’t be fed to our pets either.

Premium Commercial Pet Foods

Premium commercial foods are generally good, however, it is important to read the label and only purchase from highly respected companies*. The Animal Protection Institute sums the pet food industry up succinctly when it states, “?the pet food industry is an extension of the human food and agriculture industries. Pet food provides a market for slaughterhouse offal, grains considered ‘unfit for human consumption,’ and similar waste products to be turned into profit.” According to Michelle Bernard, author of Raising Cats Naturally: How to care for your cat the way nature intended, mycotoxins are another potential side effect of the use of grains in dry cat and dog food. Michelle Bernard explains, “Mycotoxins are naturally occurring fungal by-products that can cause disease and death in dogs and cats.” Mycotoxins develop when the grain is improperly stored. When grains are kept at temperatures above 82 degrees and over 80% humidity, fungi can produce mycotoxins grow. Mycotoxins are extremely carcinogenic and suppress the immune system.

Top 3 Ingredients

Food, where the top 3 listed ingredients are corn or other grains and by-product or by-product meal, should be avoided. By-products are parts of an animal that are not normally consumed by people, like lungs, spleen, brains or feet. All By-products are not necessarily bad, but it is impossible to tell from the label the quality of these ingredients. It is also recommended that foods with chemical preservatives like BHA, BHT, and ethoxyquin be avoided. Also, animals select foods based on scent and taste, not color or shape-those moist and meaty chunks are loaded with harmful preservatives and dyes and are for your eye, not your pets!


It’s a good idea to supplement any diet, and especially commercial feeds (even premium), with essential fatty acids, digestive enzymes and probiotics, and a good multivitamin. (Any processing of food removes some nutrients.) Senior animals, regardless of the diet, should also be supplemented. And, remember it’s never too early to start a good vitamin, mineral and supplement regimen. Many supplements can be used early in your dog and cats adult life to prevent and stave off illness and disease. Consult your holistic veterinarian for a list of appropriate preventative measures you can take today.

Nutrition and Obesity in Senior Cats and Dogs

Is My Pet Overweight?

Alarming Statistics

The statistics are alarming. Forty percent of companion cats and dogs are overweight, a good percentage of them are obese, and over ninety percent of those overweight.

Too Much, Too Little

Most pets are overweight for one reason, and one reason only: Too many calories, and too little exercise!

Yes, medical conditions such as thyroid disorders can cause an increase in weight. A holistic veterinarian should evaluate any animal who is markedly overweight, especially if the weight gain was rapid. Nevertheless, no matter how you slice it, like most people cats and dogs are overweight because they eat too much and exercise too little. And just like for us, being overweight increases the risk of serious medical problems like diabetes, degenerative joint disease, and heart, lung, and kidney problems.

How to Tell if Your Companion is Overweight
It’s easy to tell if your companion is overweight. At their ideal weight, you should be able to feel each rib as you run your fingers along with your cat or dog’s rib cage. There should be a definite narrowing behind the ribs when viewed from above and their abdomen should tuck up behind the ribs when viewed from the side.

Weight Loss

In principle weight loss is easy: Feed less and exercise more. It is difficult when big brown eyes are looking up from behind the food bowl asking for more, or when we come home from a long day and the last thing we want to do is go for a walk to the park. Or just as bad is when we hear the nonstop meow that translates as I want a treat, pretty please. (It’s important to remember that cat and dog treats, just like foods can be good and bad. Most off-the-shelf treats are very high in carbohydrates and preservatives.)

Your holistic veterinarian should supervise weight loss programs. This is especially important for cats because if a cat’s calorie intake is reduced drastically they are prone to a potentially fatal disorder called Hepatic Lipidosis. Diet changes, as well as an increase in activity,  should be done gradually.

The Proof is in the Pudding

The proof is not really in the pudding but in the health and well-being of your four-legged companion. The majority of cats and dogs will do wonderful on a variety of diets, including premium-grade commercial foods with the addition of appropriate supplements as they age or encounter stressful medical conditions.

Our Companion’s Don’t Have a Choice

It’s important to remember that our companions don’t really have any choice in what they eat; we make that choice for them. As we make that choice in knowledge our senior friends will stay healthy and fit to enjoy a long and joyful life.

*The Whole Dog Journal annually publishes a list of approved dry dog foods – Subscription details for the Whole Dog Journal.



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