Good nutrition is one of the most important steps to good health!

 

Natural Eating Behaviors in the Cat

During their nursing phase, young feral kittens are already practicing the skills they need to successfully hunt—play behavior such as chasing and pouncing lays the base for future prey catching success. As the kittens are wrapping up their nursing phase, their mother will bring home prey that is still alive so that the kittens can refine these skills. Then the queen will start to take them along on hunting forays so that they can watch her and model her behavior.

If you watch feral cats out prowling the fields and forests, you will soon notice that they spend quite a lot of time carefully stalking their prey. These cats have a very lean, muscular body condition. The normal diet of feral cats includes small mammals such as mice, moles, voles, and also birds. Cats are not garbage hounds like dogs if they have lots of prey at hand, but they may periodically scavenge a fresh discard. Cats in the wild do not go fishing by the way!

Both day and night hunting forays are carried out. A cat’s vision is designed for low light, and their activity peaks in the evening hours and early morning. The prey goes into the cat’s digestive system with only cursory chewing. These large pieces are digested in a rather short digestive tract, and processing of 5-7 small prey in about 24 hours is not unusual. Feeding behavior is interspersed with social time, grooming and sleeping.

Though cats will chew on grass and plant leaves, plant is not considered a significant component of their diet. Cats are classed as pure carnivores—those are animals that require prey to meet their nutritional requirements. Their teeth are like scissors—built to cut tissues, not grind up plants!

Modern Diets and Feeding

Of course, we don’t stock small furry animals at home in our pantry so that Kitty can enjoy hunting her meals on wheels. If anything, we hope that the odd stray dormouse finds a way out of the home without meeting Kitty’s sharp fangs!

Modern diets do not need to be chased down! This is important to remember when trying to prevent obesity in cats. Our couch and window potatoes can easily take in more food than they really need, and gain weight. Cats do not need to be fed large amounts of commercial food to maintain a lean and fit body condition. See the articles Feeds and Feeding and Purchase Decisions for information about feeding our modern sedentary cats.

As researchers learn more about feline nutrition, the manufacturers continue to update the prepared diet formulations so they more closely match the natural diet. Increased levels of taurine, protein, fats, and decreased levels of carbohydrate in the manufactured foods are some recent trends. Formulations that help prevent oxalate and struvite- type urinary tract stones, and diets containing adjusted balances of soluble and insoluble fiber have resulted from ongoing research. Manufacturers continue to fine tune their processed diets.

Special Nutritional Requirements of the Cat Species

Cats are obligate carnivores. This means that they must eat animal source food to meet their nutritional needs.

Cats have some dietary peculiarities we should understand; here are some of the key things we need to know :

High amounts of high quality animal-source protein

Protein is essential for energy production, and for maintenance of many body tissues including muscles. Beef, chicken, pork, fish, liver and by-products are examples of protein sources. Typical foods have historically provided from 34-53% protein (on DM or Dry Matter basis). Newer research has led to introduction of higher average protein (45%-55%) levels in some foods.

Taurine supplementation of diets has also been boosted since research showed that many cats with a heart problem called Dilated Cardiomyopathy or blindness were taurine deficient. Taurine is an essential amino acid in cats. Canned food needs to have twice as much taurine put into the food to achieve adequate body levels of taurine. Some think that this is due to inactivation of a portion of the taurine during high temperature processing of canned foods.

The protein should be of animal source since plant protein amino acid balance is not optimal for felines. Some of the special amino acid requirements for cats include:

• Taurine
• Arginine
• Lysine
• Cysteine
• Methionine
• Tyrosine

High amounts of animal source fats

Fats play a role in energy production, and the growth and development of many tissues—skin and hair are examples. Fat and oils help to make the food tasty. Animal fat (tallow, lard) and fish oils are frequently used in cat diets. Flaxseed oil is an example of a plant source. Fish oils are polyunsaturated oils that are high in omega-3 fatty acids, which play important roles in the skin, circulatory and urinary tracts to improve circulation and decrease inflammation. Omega-3 fatty acids are derived from alpha-linolenic acid, while omega-6 fatty acids derive from linoleic acids.

Kittens need up to 35% fat in the diet, while adults need up to 30% fat (DM). Typical fat ranges for commercial food have historically ranged from 15-25%. Modern foods feature higher percentages of fat. An essential fatty acid in the cat but not in most other species is arachidonic acid. Animal source foods provide good levels of this important nutrient.

Low carbohydrate / sugar / starch

This nutrient class is important for energy production, but much less so than in dogs and in people. Grains such as corn are often selected to provide carbohydrates in the diet. Dry foods tend to be higher than canned foods in carbohydrates because kibble structure utilizes carbohydrate for scaffolding.

Cats lack the saliva amylase enzyme to process starch. As well, there are low levels of all starch and sugar processing enzymes down in the small intestine, so cats cannot digest this class of nutrient efficiently. Cats also do not have a sweet tooth—like doggies and us! This reflects the cat’s natural low sugar diet of animal source food. A good example of sugar intolerance is when cats are given milk, which contains the milk sugar lactose. If milk is not fed regularly after weaning, the enzymes that process the milk sugar will not be active, so the sugar enters the lower intestine unprocessed. The bacteria there ferment it, and the sugars draw water into the gut, leading to diarrhea.

Moderate Fiber

Cats normally take in fiber when eating small prey. Fiber helps give the cat a “full” feeling after eating because it acts as a bulking up component. Too much or too little is not good. Grass grazing on a limited basis is also done if given an opportunity, and grass contains some fiber.

Excessive fiber or not enough fiber can lead to trouble with mobility of the guts. Hairballs are an example of a fiber buildup that can lead to blockage or reduced transit along the gut. Low fiber can lead to constipation because fiber acts to stimulate the gut contractions that move things along and out.

There are two types of fiber: soluble and insoluble. Research is now being carried out to determine the optimum proportions of each since fiber is important for normal digestion. Volatile fatty acids are found in the digestive tract and play a role in controlling gut inflammation—certain fiber types help to normalize the gut environment.

Vitamins and minerals

Cats cannot make their own vitamin A. They lack to ability to change the vitamin from a plant source (beta-carotene) into retinol, the active form—animal tissues have the retinol form of vitamin A in good supply.

Vitamin B: A daily source of niacin, riboflavin (B 2) and thiamine (B 1) is important because cats do not store these efficiently.

Thiamine may be destroyed during food processing, or when food is stored for long periods, or if fish is fed since many fish contain thiaminase enzyme which inactivates the vitamin.

High levels of pyridoxine (B 6) are needed to help process the high protein diet.

Cobalamin (B 12) deficiency is only a problem in cats fed vegetarian diets.

Vitamin D cannot be converted in the skin using sunlight as with people. Cats therefore need their source from animal tissues. Low vitamin D or an imbalance of calcium and phosphorus can lead to rickets in young cats.

Calcium, phosphorus and magnesium are three very important minerals. The proper balance of these key nutrients is essential for proper bone growth. Bone meal is frequently used as a mineral source in the formulation of the food. The ratio of calcium and phosphorus will be closely controlled in manufactured foods. Excess magnesium also plays a role in formation of struvite stones in the urinary tract.

Sodium and chloride (salt) is a key nutrient, and potassium is another that must be in balance to prevent body-wide side effects.

Trace elements such as copper, iron, selenium, zinc, iodine, chromium and manganese play roles in the body for enzyme reactions and other processes.

Water

This component is essential for life. Because cats evolved in arid climates, they have naturally concentrated urine and low water intake. Fresh water should be provided at all times though. Note that cats eating dry food will take in only half of the moisture (from water bowl and food combined) compared with cats eating canned food! This means encouraging water intake is especially important in cats fed kibbles only.

Wild type food!

A typical rat carcass (for comparison with commercial diets) is 55% protein, 38% fat, 9% carbohydrate and 1% fiber. Just thought you’d like to know!

Starvation / Low Food Intake

Cats are designed to take in 4-8 meals a day. Their metabolism is peculiar since they do not hold lots of glycogen (stored energy source) in their liver like we do. We call on these stores if food intake drops off suddenly, but cats have low levels on reserve.

As well, they have nitrogen processing enzyme systems that run all the time to protect the cat against high ammonia levels and excess amino acids as a response to the high protein diet. This combination of species differences means cats do not respond to loss of food intake like we do—they are adapted to use fat and protein for energy, with only limited ability to use carbohydrates.

A serious disorder called Fatty Liver can occur when food intake is stopped. This condition leads to fat build up in the cells of the liver. The whole system gets seriously out of balance, leading to a vicious cycle of loss of appetite and worsening metabolic state. Especially with obese or ill cats, it is extremely important to make sure that Kitty eats something each and every day! See our Liver and Pancreas article for more information.

Single Component Diets

The typical finicky cat will not self-select a balanced diet. She would much rather pick out only the part she favors, and leave the rest for you to clean up!

A common mistake owners make is to feed Kitty just tuna or liver as the sole diet because she likes it and turns her nose up at other things. This can have life threatening consequences as a tuna-only or liver-only diet is seriously imbalanced!

Tuna Diet : Feeding only tuna, especially red tuna, or fish diets leads to deficiency of Vitamin E (alpha-tocopherol). The result is pansteatitis (Synonyms: steatitis or yellow fat disease). This is an inflammation of the fatty tissues, and the fat becomes lumpy, hard and painful. This leads to reluctance to move, stiffness, severe pain when petted, fever, and eventually death if not treated.

Liver Diet: Excess Vitamin A is toxic. Fresh beef liver is a rich source of preformed Vitamin A (retinyl palmitate). If only liver is fed, the muscles will be sore, and hyperesthesia of the neck and shoulder / forelimbs occurs (this means that the skin is hypersensitive to the touch). See article Feline Hyperesthesia Syndrome for more information on this condition.

The soreness and sensitivity is related to bony overgrowth in the neck portion of the spine, ribs and front limb bones. Severe skin lesions and weight loss and appetite loss may co-exist. Excess vitamin A will also cause liver toxicity.

Understanding the special nutritional needs and eating habits of cats is an important first step. Your veterinarian will help you select the right diet for your cat.