In this exclusive excerpt from his new book CANINE NUTRITION, author Lowell Ackerman,
DVM, Ph.D, examines the nutritional needs of dogs throughout their various life
stages and activities.
Dogs are very versatile when it comes to meeting their dietary needs. They are
not strict carnivores by nature. They do have teeth for tearing flesh and their
digestive tracts are short and simple, but they do not have a strict requirement
for meat in their diet. Meat protein is easier for dogs to digest and contains
more optimal blends of amino acids from which proteins are made. In the 20,000
or so years that dogs have been man's companion, however, they have gradually
become accustomed to the foods we eat, and have lost their need to be strict
carnivores. By comparison, the cat is still a strict carnivore and must receive
animal protein in its diet.
Nutritional needs for a dog change during his lifetime. Nutrients that are critical
when he is a pup are less important when he reaches adulthood. A bitch has different
needs when she is pregnant or lactating than when she is spayed or not used for
breeding. Finally, as your dog ages, his nutritional needs also change. Superimposed
on this is the realization that other factors such as sporting competition, the
show circuit and disease have an impact on nutrition.
Feeding the Newborn Puppy
Soon after pups are born, they should begin nursing their mother. Their level
of nutrition will parallel that of the dam. Pups must nurse extensively during
the first 24 hours because that is when they receive the antibody-rich colostrum
from their mother. Colostrum helps protect them from infection for the first
two to three months of life. Pups should be allowed to nurse for at least six
weeks before they are completely weaned from their mother. Supplemental feeding
may be started by as early as 3 weeks of age.
It is critical that puppies nurse effectively. The energy needs of growing pups
are nearly three times what they are for an adult when compared on the basis
of metabolic body size. Small or weak pups must be closely supervised because
they may appear to nurse yet can eventually weaken and die. If they nurse ineffectively,
they may ingest only air, not milk. If the bitch has limited milk supplies, it
is best to let the smallest pups drink their fill and supplement the larger ones
with milk replacer. Weak puppies that do not improve within a few hours must
be tube fed or given some other method of supportive therapy.
Feeding the Growing Puppy
By 2 months of age, pups should be fed puppy food. They are in an important phase
of life-growth! Skeletal development is at its peak for the first six months
of life. Nutritional deficiencies and/or imbalances during this period are more
devastating than at any other time. During this phase, your dog develops a functioning
immune system, dramatically adds bone and muscle mass, and he learns all about
his new environment, developing proper socialization behaviors all the while.
There is no more critical time to ensure proper nutrition.
This is not the time to scrimp on nutrition. Puppies in their active growth phase
should be fed a high-quality diet that meets their specific nutritional needs.
Purchase a food specially designed for this growth period, and be certain that
feeding trials have been conducted by the manufacturer. Keep pups on this diet
until 12 to 18 months of age, depending on the breed. Many large breeds do not
mature until 18 months of age and so benefit from a longer period on these rations.
When it comes to feeding schedules, most puppies do best being fed at specific
times throughout the day rather than having food available at all times. Put
the food down for 20 to 30 minutes, then remove it until the next feeding. Pups
initially need to be fed two to three meals daily until they are 3 to 4 months
old. By 3 or 4 months of age, many puppies can be fed three meals daily. Continue
this schedule until they are 12 to 15 months old, then feed twice daily when
they are converted to adult food.
It is important for pups to receive regular feedings, but it is just as important
that they not be overfed. Puppies that are overfed, especially the large breeds,
are more prone to bone diseases when they grow too fast or become overweight.
Keep pups lean and healthy during their growth phase, and disorders such as hip
dysplasia and osteochondrosis are less likely to occur.
It should come as no surprise that the nutritional needs of pups are different
from those of adults. Even the amino acids needed are different, and pups require
much more arginine than adults. They also require many more calories. Vitamin
and mineral imbalances can be disastrous for a puppy. Vitamin E deficiency can
cause muscle degeneration in pups, while choline deficiency can interfere with
liver function. Pantothenic acid deficiency impairs the growth rate, and fewer
antibodies are produced when pups are exposed to viruses. Vitamin D deficiency
can result in osteoporosis, while vitamin A deficiency can cause abnormal bone
development, eye and skin problems and a greater susceptibility to infection.
All of these can be prevented by providing a high-quality diet designed specifically
for this important growth phase.
One pitfall to be avoided is supplementing pups with protein, vitamins or minerals.
It is easy to become overzealous with supplements, but this is not wise. Most
of the mistakes are made with supplements containing calcium, phosphorus and/or
vitamin D. You may think that these supplements will help your growing puppy
by adding to his calcium resources. After all, children are encouraged to drink
milk to build strong bones and teeth. Why not pups? The reason is because growth
rations have been formulated with an ideal ratio of calcium to phosphorus, usually
around 1.3 parts calcium to every 1 part phosphorus. This is the optimal ratio
for healthy bone growth. This can be quickly unbalanced by providing calcium,
phosphorus, vitamin D, or combinations.
There is more than adequate proof that these supplements are responsible for
many bone deformities seen in growing dogs. Avoid the temptation to supplement.
If you really must supplement, select moderate amounts of the water-soluble vitamins
(vitamin C and the B vitamins) instead of the minerals or fat-soluble vitamins.
If you must select a fat-soluble vitamin for supplementation, use vitamin E rather
than vitamins A, D or K.
Now is the time to ensure optimal nutrition and create proper eating habits that
will last a lifetime. Learn how to feed pups amounts that won't make them fat,
but don't deprive them either. And, don't try to second-guess nature by supplementing
the diet with potentially dangerous nutrients, even if it appears to make sense
on the surface. This is definitely not the time to make mistakes with your dog's
Feeding the Adult Dog
When pups become adults, they enter a new nutritional phase - maintenance. Once
they've finished growing, the "growth" diets provide more calories and protein
than they really need. If they continue on the growth diets, they may become
obese. The goal is to switch them to a maintenance ration that is balanced correctly
for this phase of life.
The term "maintenance" is used loosely, but it is important to understand what
is really meant by it. Dogs require maintenance rations when they are living
a comfortable and relatively stress-free existence as a housepet. A dog staked
by a four-foot-long chain in the backyard is not being "maintained." A dog tossed
outside at night in the cold to patrol a lot is also not being "maintained." The
maintenance energy requirements can be calculated with a mathematical formula
for dogs that are not kept as housepets. This book is dedicated to the caring
dog owner, however, and these exceptions will not be discussed.
There are many choices when it comes to selecting a maintenance diet. Most commercially
available foods are combinations of animal-based and plant-based ingredients.
The animal-based ingredients are tastier for dogs and easier for them to digest,
but the plant-based ingredients are cheaper. To be cost-effective, most commercial
dog foods blend ingredients from both plant and animal sources.
In general, dogs can do well on maintenance rations containing predominantly
plant- or animal-based ingredients as long as that ration is specifically formulated
to meet maintenance-level requirements. This contention should be supported by
studies performed by the manufacturer in accordance with American Association
of Feed Control Officials (AAFCO). In Canada, these products should be certified
by the Canadian Veterinary Medical Association (CVMA) to meet maintenance requirements.
There are many criteria by which you might select a dog food for maintenance
purposes. A dog that is fairly sedentary, has finished growing, is not in competition,
and is not being used for breeding can accommodate varying amounts of dietary
fat, protein, and carbohydrate. They are the classic low-stress dogs for which
the maintenance requirements were designed. These dogs do well on most commercial
or homemade diets. In fact, it is probably a mistake to feed these animals super-premium
dog foods because they tend to become obese.
Many manufacturers of premium dog foods market their products on the basis of
ingredients. Most of the super-premium diets have a higher content of meat and
meat byproducts. Most of the cheaper brands of dog food have a higher content
of cereal. It is not always easy, however, to tell the difference by looking
at the pet-food label. For instance, the label may read "chicken, corn-gluten
meal, ground corn, ..." and so on, leading you to believe that chicken is the
main ingredient. In fact, by dividing corn into individual ingredients such as
ground corn, corn-gluten meal, corn flour, and corn bran, the total cereal content
of the diet may be camouflaged. You think you're feeding a predominantly chicken-based
diet when cereal is actually the primary ingredient. Canned pet foods contain
more than 75 percent water, yet this can also be confusing when you examine the
label. It may list chicken or beef as the main ingredient but when you examine
the analysis, it lists "moisture" at about 78 percent.
There's nothing wrong with feeding a cereal-based diet to dogs on maintenance
rations, and this is the most economical diet. Unfortunately, corn is low in
certain essential amino acids, and this must be remedied by complementation,
a process combining different protein sources to provide a suitable blend that
does meet requirements. In the least expensive brands, this can often be done
by selecting soy as a vegetable protein source. Most dogs tolerate soy well,
but some dogs are soy intolerant and do not do well on these rations. Certain
breeds, such as the Irish Setter, the Siberian Husky and the Chinese Shar-Pei
have a higher incidence of soy intolerance, although any breed is susceptible.
Soy also contains some sugars (e.g., raffinose, stachyose) that are not digestible
by dogs but that are digestible by bacteria. As a result, the sugars may get
digested by microbes in the colon, producing gas. This may contribute to flatulence
or "windiness" in a dog. Other ingredients in soy can also be problematic if
the food is not processed adequately.
Keep in mind that maintenance rations meet only the minimum requirements for
stress-free house pets. There are many stressful situations that can change a
dog's nutrient requirements from maintenance levels to above-maintenance levels.
Dogs housed outside in cold weather, dogs that are exercised extensively, dogs
that are used for breeding, and dogs that are ill often will benefit from eating
foods that provide more than just minimum requirements. Also, most of the dogs
that are first switched from puppy foods to maintenance foods still have some
growing to do. It is therefore recommended that you feed your dog a diet that
contains easily digested ingredients that provide nutrients at least slightly
above minimum requirements. Typically, these foods will be intermediate in price
between the most expensive, super-premium diets and the cheapest generic diets.
Select diets that have been substantiated by feeding trials to meet maintenance
requirements, that contain wholesome ingredients, and that are recommended by
your veterinarian. Don't select a food based on price alone, on company advertising,
or on total protein content.
Feeding the Aging Dog
Dogs are considered elderly when they have achieved 75 percent of their anticipated
life span. This obviously differs for each breed. A Great Dane may be considered
old at 6 years of age, while a Poodle may not be seen as elderly until 10 years
of age. And, there is so much variability between individual dogs that even breed
generalizations are merely guidelines. It is important to recognize the needs
of these "senior" pets before the onset of age-related problems, while nutrition
can still provide the best preventive medicine.
As a dog ages, his metabolism slows. There is a decreased sense of thirst that
can result in dehydration if not detected. At the same time, if maintenance rations
are fed in the same amounts and metabolism is slowing, weight gain is common.
Obesity is the last thing you want to contend with in an elderly pet, because
it increases the risk of other health-related problems. On the other hand, an
elderly dog may lose weight, and this is not good either. The older dog doesn't
have as acute a sense of smell as he had when he was younger. Dental problems
also plague him. Approximately 85 percent of dogs over 4 years have periodontal
disease. This can result in painful chewing, infection and tooth loss. All of
these conditions can contribute to undesirable weight loss as your dog ages.
Dental health care is an important part of overall wellness. Don't wait until
your dog is old to consider the impact of routine dental care.
As dogs age, most of their organs do not function as well as they did in youth.
In the digestive system, the liver, pancreas and gallbladder do not work at peak
capacity. The intestines have more difficulty extracting all the nutrients from
the food consumed. The colon doesn't have the motility that it used to have,
and constipation becomes more common. In the cardiovascular system, the heart
has been beating relentlessly for years and is more likely to show the effects
of overwork. The blood vessels aren't as flexible anymore, and the heart valves
are not as efficient. The kidneys contain a finite number of filtering units
that are not replaced as they succumb. A gradual decline in kidney function is
considered a normal part of aging.
A responsible approach to geriatric nutrition is to realize that degenerative
changes are a normal part of aging. The goal is to minimize the potential damage
by taking appropriate measures while your dog is still well. If you wait until
your elderly dog is ill before you change his diet, the job will be much harder.
A geriatric diet often provides fewer calories per serving than the growth or
maintenance rations to accommodate a slower metabolism. If the energy content
of the diet is not restricted, but a dog exercises less, then he will become
obese. Of course, this is not true for all senior dogs. If your dog loses weight
with age, you may need to increase the calorie content of his diet. If your dog
tends toward obesity, however, you will need to reduce the fat and protein contents
of the diet and provide more calories in the form of easily digestible carbohydrates.
Older dogs benefit from essential fatty acids like linoleic acid but have little
need for saturated fats or other oils. If you provide high-quality vegetable
oils (safflower oil, flaxseed oil), you will meet the essential fatty acid requirements.
These oils also allow for the absorption of the important fat-soluble vitamins.
Most elderly dogs do better on diets that are easily digested. Geriatric diets
are typically low in fiber because dogs have a difficult time absorbing fiber.
There are some medical conditions that benefit from fiber, including diabetes
mellitus, colitis and constipation, and a geriatric diet can be augmented with
psyllium (Metamucil) or pectin if your dog requires a higher fiber content. Because
the digestive system becomes less efficient as a dog ages, a diet that is more
digestible is also more likely to provide needed vitamins, minerals, amino acids
and essential fatty acids.
Older dogs don't need more protein in their diet, but they do benefit from better-quality
protein. The protein content of the diet is only a source of essential amino
acids. Protein is typically hard to digest and requires metabolism in the liver
and filtering by the kidneys. All of these functions can be impaired in the older
dog. Your goal is to provide lower levels of total protein (typically 14 to 21
percent of dry matter) but higher levels of the essential amino acids. You need
to provide your aging dog with the proteins that do the most good. If you severely
limit protein in your elderly dog's diet, especially if he is losing weight,
you can induce protein deficiency and adversely affect immune function and enzyme
It is very important to understand the dynamics of vitamin and mineral nutrition
in the older dog. Older dogs need higher levels of vitamins A, B1, B6, B12 and
E than they did when they were younger. Zinc is also needed to help with body
repairs and to bolster the immune system. Most maintenance diets are much too
high in sodium (salt) for the geriatric dog and the levels are restricted in
the "senior" diets. These diets also take into account the changing dynamics
of calcium and phosphorus metabolism and slightly reduce the phosphorus content
to lessen the workload of the kidneys.
There are many options for feeding your senior dog. Ideally, you should change
his diet when he is still healthy and has not slowed down too much or become
ill. Switch him to a senior diet when he has achieved about 75 percent of his
expected life span, or when recommended by your veterinarian. This may stall
the onset of heart, kidney and digestive disorders by being more "user-friendly" and
not overtaxing his system. For example, a low-protein diet may not prevent kidney
disease, but it certainly is easier to handle for a dog experiencing any impairment
of kidney function. The diet should contain ample amounts of the amino acids
that dogs require and lesser amounts of the ones deemed dispensable. A low-salt
diet won't necessarily prevent heart disease, but it is certainly helpful in
dogs with impaired cardiac efficiency.
Elderly dogs need to be treated as individuals. While some dogs benefit from
the nutrition found in "senior" diets, others might do better on the highly digestible
puppy and super-premium diets, which provide an excellent blend of digestibility
and amino acid content. Unfortunately, many are higher in salt and phosphorus
than the older dog really needs. It is not advisable to continue to feed your
elderly dog maintenance rations even if you cut down the amount you feed to limit
calories. Maintenance rations were formulated to meet minimum requirements for
stress-free housepets. Advancing age is a definite stress on the system, and
maintenance rations do not optimally meet the protein, fat, vitamin and mineral
requirements of an aging dog. If you must feed this diet for economic reasons,
give your dog a daily vitamin-mineral supplement designed for "seniors." These
supplements are typically rich in the B vitamins and the antioxidant nutrients
vitamin A, vitamin C, vitamin E, and selenium, as well as zinc. There is also
a good argument for providing high-quality table scraps to the very senior dog
that tends to lose weight. Freshly prepared chicken, beef, organ meats and cooked
grains and vegetables can provide a tasty and nutritious treat for dogs that
may not be eating enough of their own food. At this time of life, there is no
point in being hard-nosed about the evils of table scraps unless there is a medical
reason for doing so.
Feeding the Pregnant or Nursing Bitch
Care of the pregnant or nursing bitch presents certain nutritional challenges
which must be considered and met. Prior to being bred, the bitch should be in
good body condition, not too thin and definitely not obese. She should be in
excellent dietary status to enhance the chances of conception and then maintained
on an increasing nutritional plane as her body strives to meet the needs of pregnancy
and then lactation (milk production). It is important to understand that the
nutrient requirements may increase as much as four times over usual adult maintenance
levels. Providing proper nutrition to the reproducing dam directly influences
the quality of the milk she produces, the survival of the pups, and their birth
Usual maintenance diets are not suitable for the pregnant or lactating bitch.
They do not provide enough energy to meet her needs on a daily basis. The diet
must be complete and balanced for this stage of life and provide at least 1,600
digestible calories for every pound of food fed. This type of diet should be
introduced before the fourth week of pregnancy when nutritional demands begin
to skyrocket. Acceptable diets usually contain more meat than do regular diets,
and only certain super-premium and canned dog foods actually meet these criteria.
Many commercial canned cat foods also meet the criteria and are useful in toy
and miniature breeds of dogs. These claims should be supported by actual feeding
trials, not just lab analysis. With regular maintenance diets, the bitch is unlikely
to consume enough food to meet her actual needs. It is also difficult to "supplement" regular
maintenance diets to be suitable for pregnancy and lactation. If this option
is an economic necessity, it will be necessary to add eggs, meat (with fat) or
small amounts of super-premium canned dog foods or cat foods to the ration.
Most bitches do not show appreciable weight gain until into their fourth week
of pregnancy (gestation). Over the final month of pregnancy, it is not unusual
for food consumption to increase by 40 percent. As the pups occupy more and more
area in the abdomen, the bitch will appreciate being fed several small meals
throughout the day rather than one or two large ones. During the final two weeks
of pregnancy the pups, placenta, fluids and developing mammary glands all contribute
to additional weight gain. Within a day or two of littering, however, it is not
unusual for the bitch to lose her appetite. It normally is recovered within a
day after whelping. It is important that the bitch not be underweight or overweight
at this time. Underweight bitches may have difficulty meeting the nutritional
needs of the pups after whelping. Overweight bitches have more trouble with delivery,
have less efficient lactation and increased risk of complications for the puppies
After whelping, the dam has an additional nutritional drain. She now has attentive
pups hungering for her milk and the challenge of meeting her own needs in the
process. She may not have time or inclination to leave the pups so care must
be taken to make her food and water accessible, palatable and laden with energy
(calories). As the pups grow so does her need to provide for their nutritional
needs. This reaches a zenith when they are about 3 to 4 weeks of age, at which
time she may be consuming two to four times the amount of calories she did when
she wasn't pregnant. After this time the pups start to take more of an interest
in solid food and demand for milk then diminishes. When the pups are fully weaned
at 6 weeks of age, the food consumption of the dam is down to about 50 percent
above non-pregnant levels and continues to diminish.
Nutritional supplementation can be helpful during pregnancy within very strict
guidelines. It is much better to provide a wholesome, well-balanced diet than
to predict the benefits of nutritional supplements. A good choice would be a "senior" vitamin-mineral
supplement that includes the B vitamins, vitamin E and zinc. Supplements containing
significant amounts of calcium, phosphorus or vitamin D should only be given
under the direction of a veterinarian.
Feeding the Stud Dog
With so much attention focused on the brood bitch, sometimes the stud dog gets
short-changed. Males need proper nutrition too if they are going to perform reproductively
at their best. Dogs shouldn't be too thin, or too fat, but being normal to slightly
overweight is best. Dogs that are too thin or too fat often have medical problems
that could affect their ability to properly mate and impregnate a bitch. The
amount and type of food fed should be adjusted, before breeding, to bring the
male in optimal body condition.
Most stud dogs can be maintained on moderately priced dog foods and do not require
the energy-dense foods fed to the brood bitch. However, check the label and make
sure the ration has been assessed by feeding trials (AAFCO or CVMA). The diet
should be fed so that the dog maintains optimal body condition, not necessarily
the recommended level on the label. Stud dogs are individuals and some may require
more or less than recommended to maintain optimal body condition.
Currently, research is underway to examine in more detail the role of specific
nutrients in sperm development. For example, deficiencies of beta-carotene and
vitamin A have resulted in testicular degeneration in other species; ascorbic
acid may be involved in normal sperm production; pyridoxine is involved in the
release of pituitary hormones; chromium is important in maintaining the integrity
of nucleic acids; and zinc has been reported as a cause of testicular degeneration
in some species. However, there is not enough research done in the dog to make
any specific recommendations.
Avoid the temptation to supplement the stud's diet, although some healthful meat
and vegetables isn't a bad idea. Most vitamin-mineral supplements will not perk
up the sperm, and some have definite adverse effects. A standard one-a-day vitamin
is fine, but high doses of specific nutrients are not recommended.
Feeding the Show Dog
The requirements for feeding a show dog are significantly different from those
for a field trial dog and also different from the typical maintenance ration
for a sedentary house pet. The goal of feeding the show dog is to optimize the
physical characteristics of the dog, not meet its minimum dietary requirements.
Most breeders are adamant about the foods they will and won't feed their dogs.
When they sell puppies, they often provide dietary recommendations for "what
works for them." Whether there is any scientific rationale for the choice often
takes a back seat to personal experience. Even poorly balanced diets may produce
a champion and this attests more to the resiliency of dogs than to the intuitiveness
Most show dogs benefit from a blend of protein, fat and carbohydrate and do not
need the energy-dense format found in performance diets. These performance diets
often provide too much fat, and the wrong kind of fats to promote good skin and
haircoat. A maintenance ration containing "wholesome ingredients" should be provided
and it needn't be high in protein, fat or carbohydrate. These dogs truly benefit
from a "balanced" ration, not one of extremes.
Most dog foods intended for show dogs are primarily meat-based. Soy protein contains
much indigestible fiber and some highly-bred canines do not tolerate soy as well
as meat. Chicken, beef, pork and lamb are all well digested by dogs. If these
ingredients make up the protein basis of the dog food, a high-protein ration
is not needed. Meat protein provides ample amounts of the essential amino acids
that are required. If there is too much meat in the diet, the content of saturated
fat will also increase and this is counterproductive to enhancing the skin and
hair coat. By incorporating easily digestible carbohydrates into the diet, such
as rice, potatoes or corn starch, calories can be provided without relying on
high levels of fat or protein.
Supplementation of foods intended for show dogs is commonplace and so there is
no point in recommending against it. It is better to discuss options for sensible
supplementation that does not "unbalance" a balanced ration. If the starting
point is a good-quality "maintenance" ration rather than a performance ration,
better results will be seen with or without supplementation.
Fat and oil supplements are commonly given to dogs, and the show dog is no exception.
Unfortunately, these fats and oils are often poorly formulated and provide more
calories than essential nutrients. The purpose of supplementing with fats is
to provide the essential linoleic acid to the diet. The best source of this fatty
acid is safflower oil or flaxseed oil. Corn oil is only about 50 percent linoleic
acid, and the other vegetable oils contain even less. It is cheaper and more
effective to purchase safflower or flaxseed oil directly rather than the vegetable-oil
mixtures found in pet-supply outlets. Don't overdo it - add no more than a tablespoon
per day to the food. Another fatty acid that might be helpful to skin and hair
coat is gamma-linoleic acid, found in evening primrose oil or borage oil. These
can be found in health food stores or may be purchased from your veterinarian.
Veterinary products often combine the plant oil with marine oil for added benefit;
the combination product is not currently available from health food stores.
Protein supplements are not needed for the show dog and can be harmful. The real
need is for essential amino acids, which are present in the protein source itself.
All protein ingested is "broken down" first to individual amino acids. The most
important amino acids for skin, hair coat and claws (nails) are the sulfur-containing
methionine, cysteine and cystine. Additional protein in the diet cannot be stored
and will be converted to fat or excreted by the kidneys.
Vitamins and minerals are important to healthy skin and fur, but indiscriminate
supplementation is unlikely to be beneficial. A general "stress" vitamin-mineral
supplement is helpful, as it provides a broad spectrum of important B vitamins
and antioxidants such as vitamin A (or beta-carotene), vitamin C, vitamin E and
selenium. It is unwise to supplement with additional calcium and phosphorus,
because this frequently results in bone deformities in growing dogs.
Many other supplements that have no scientific rationale are used by breeders.
Some of the most common are brewer's yeast and kelp. Brewer's yeast is a good
source of B vitamins, but it also lacks the much-needed vitamins A, C and E.
Despite the contentions of many to the contrary, scientific studies of brewer's
yeast have not found it to repel fleas.
Kelp is a type of seaweed and is indeed a rich source of vitamins and minerals.
It is not nutritionally complete on its own but does provide several useful amino
acids in addition to the vitamins and minerals. In most cases, if a dog improves
on brewer's yeast of kelp, it indicates that the food being fed previously was
not properly fortified. In this instance, it is usually more cost-effective to
switch to a better diet than to continue supplementing with these products.
Lowell Ackerman is a veterinarian and nutritional consultant. The past editor
of Advances in Nutrition, he has authored 66 books and more than 150 articles,
and lectures extensively on the subject of nutrition across the United States,
Canada and Europe.