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The Facts About Protein
Our bodies and those of companion animals are orchestrated by cellular
machinery, which is directed according to blueprints of DNA. To do so, DNA is
transcribed into RNA and then further translated into functional proteins or enzymes.
These proteins or enzymes are present in all living cells, are critical for growth and
maintenance of the body, and are essential to the well being of both humans and
animals. For example, vital body functions, such as blood clotting, fluid balance, visual
processes, hormone balance, enzyme activity as well as energy production, all involve
proteins or enzymes. Proteins are also important structural constituents of muscle, hair,
bone and organs. Our survival relies on constant adjustments to the cellular machinery,
which is accomplished by fine-tuning the conversion of DNA into functional proteins.
The translation of functional proteins and their ability to perform optimally require a
readily available supply of amino acids, which are the building blocks of protein.
Although proteins are considered essential for healthy dogs and cats, it is not
actually dietary proteins that are utilized by the body, but rather the constituent amino
acids, which make up dietary protein. Proteins are made up of hundreds of amino
acids. The body utilizes twenty (in dogs) or 21 (in cats) common amino acids in various
combinations. While each of these amino acids are important for growth, maintenance
and health of the body, some of are considered essential amino acids and others nonessential. Essential amino acids cannot be manufactured by the body from precursors
and, therefore, must be provided by the diet. Only ten of the required 20 amino acids
are considered essential in dogs, while eleven are essential in cats. Non-essential
amino acids are synthesized in the body from precursors and, therefore, need not be
present in the diet if adequate amounts of essential amino acids and energy are
provided to the animal. Non-essential amino acids are just as vital to the makeup of
proteins and crucial for metabolic reactions in the body as essential amino acids.
Once dietary protein is consumed, its digestion begins in the stomach where
enzymes break down proteins into individual or small groups of amino acids. The
amino acids are then absorbed by the intestine and eventually enter the bloodstream to
be distributed to the body’s cells and tissues. The fate of absorbed amino acids falls
into three general categories: 1) synthesis of tissue protein, 2) manufacture of
enzymes, albumin, hormones or other nitrogen-containing compounds and 3)
manufacture of energy (or fuel) for the body. Additionally, body proteins are
continuously being broken down and new ones manufactured. This process is referred
to as protein turnover and is a key physiological process for humans, dogs and cats
alike. Protein turnover helps us adapt to our ever-changing environment by maintaining
a readily available supply of amino acids necessary to manufacture proteins or enzymes
needed at any given time.
An optimal level of dietary protein, or rather amino acids, is important in order to
maximize the rate of protein turnover, maintain strength and function of skeletal muscle,
and support a healthy immune system. Not only is an optimal level of dietary protein
important, so is the quality of protein. That is, dietary protein must contain the right
balance of amino acids required by the animal and must be highly digestible. Without
adequate levels of high quality dietary protein the body compensates by slowing down
the rate of protein turnover, thus, decreasing the body’s ability to respond quickly to
changes in its environment. For example, to effectively protect and defend the body,
the immune system must be able to respond rapidly to potential infections, pathogens
and environmental stresses. Amino acids supplied by protein turnover are critical in the
manufacture of cells and components of the immune system, such as T-cells and
immunoglobulins, respectively. When protein turnover rates are reduced in animals
because of low dietary protein intake, the animal is more sensitive to infections and
other environmental stresses. Also, without an adequate level of dietary protein to meet
the animal’s needs, a protein deficiency may occur. A severe protein deficiency can
cause poor food intake, slow growth, weight loss, rough or dull hair coat, or hair loss,
impaired immune function and decreased resistance to disease and infection. Chronic,
marginal protein deficiency may result in decreased protein reserves, and those animals
with inadequate protein reserves may appear healthy but are more susceptible to
infectious and cancer causing agents [Allison et al., 1954, McCoy et al., 1956]. A more
detailed description of the function of proteins follows.
Making up more than 50% of the dry weight of animals, proteins are vital to the
proper regulation, function and maintenance of the body. Amino acids absorbed from
the gut are rebuilt into new proteins, such as for the:
• manufacture of enzymes which are catalysts (e.g., speed up) of all metabolic
functions, including energy production, neurological function, immune response and
maintenance and health of entire body
• manufacture of special blood proteins that serve as carriers for vitamins and
minerals and are critical for the general health of animals
• manufacture of hormones such as insulin which are necessary to regulate metabolic
functions
• manufacture of energy (or fuel) for intestinal cells and skeletal muscle. In fact,
proteins yield the same amount of usable energy as do carbohydrates
• manufacture of structural proteins such as collagen, elastic, keratin, actin and
myosin
2
Purina’s Pioneering Research in the Nutritional Management of Canine Food
Allergies
Introduction
It has been estimated that 15% of dogs suffer from allergic diseases [Baker,
1990]. The two most common types of canine allergies are flea allergy dermatitis (or
hypersensitivity to fleabites that causes the skin to react via itching and/or the formation
of papules) and atopy (allergic reaction against common environmental antigens such
as pollen, molds, house dust, mites, etc). Food hypersensitivity (or allergy) ranks third.
In fact, it is estimated that food hypersensitivity may be responsible for pruritus (or
itching) in up to 62% of dogs presenting with non-seasonal allergic skin disease [Leib
and August, 1989]. In addition to causing dermatologic problems in canines, food
hypersensitivity may contribute to chronic gastrointestinal diseases [Halliwell and
Gorman, 1989]. Specifically, food hypersensitivity appears to be involved in some types
of inflammatory bowel disease, which is currently the most common cause of diarrhea
and vomiting in dogs [Hall et al., 1989].
What are food allergens?
Food consists of a variety of allergenic and nonallergenic components. Food
allergens, however, are almost exclusively proteins. Because they are recognized as
foreign by the body’s immune system, all dietary proteins have the potential to elicit an
allergic response. In fact, most food allergens are very stable molecules that are
resistant to food processing, cooking and the digestive process [Taylor, 1992]. Because
of this, the specific amino acids sequences that make up the reactive sites (or epitopes)
of the allergen are protected. In animals predisposed to food allergy, these reactive
sites (or epitopes) are recognized by the immune system as foreign and stimulate the
immune system to produce antibodies that target the specific protein.
In order for a protein to be considered an allergen, it must be able to stimulate an
immune response by the body. The ability to elicit such a response appears to be
dependent on the size (also called the molecular weight) and structure of the protein.
Most food allergens are reported to be proteins with a molecular weight between 18,000
– 36,000 daltons [Ackerman, 1990]. In soy, for example, the major allergens are
reported to be between 20,000 and 78,000 daltons [Awazuhara et al., 1997]. Dietary
proteins smaller or larger than 18,000-70,000 daltons size range are not as likely to
cause a food allergy because of the physical reactions involved.
Potential solutions to food hypersensitivity
Companion animals suffering from food hypersensitivity may be managed
through nutritional modifications. A major tenant in nutritional management of food
hypersensitivity involves the identification and avoidance of the offending antigenic
protein. A serious drawback is that the identification of the specific dietary protein
responsible for the hypersensitivity requires a substantial commitment by both the
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veterinarian and pet owner. This approach requires an extensive dietary history on the
dog in order to identify all protein sources in the dog’s diet. Then, the dog is fed an
elimination diet containing ingredients that have not been previously consumed by the
dog. This can be a frustrating experience as it often requires the owner to prepare a
homemade diet, often not nutritionally complete and balanced, that contains one protein
source and one source of carbohydrate. For up to twelve weeks, this elimination diet
must be fed to the dog in order to resolve or reduce the symptoms. If symptoms remain
after this period of time, then food hypersensitivity can usually be ruled out. If
symptoms are resolved, then food hypersensitivity may be the culprit. In order to
confirm the specific offending protein(s), each protein source previously ingested by the
dog, must be individually re-introduced into the dog’s diet for a pre-determined time
period. If symptoms reappear then the dog likely has a hypersensitivity to that particular
protein. After identification of the protein causing the hypersensitivity, the dog is
maintained on a diet that is devoid of the offending protein.
Until recently, veterinarians managed the food allergic dog by feeding “novelprotein” diets, which are formulated with proteins not normally found in pet foods, such
as venison or rabbit meat. These “novel-protein” products should be carefully examined
because many commercial diets based on “novel-proteins” may contain other
ingredients that contribute significant amounts of non-novel proteins. For example,
carbohydrate sources like pinto beans and oats groats contain a substantial amount of
protein (21% and 18%, respectively). Moreover, these “novel-protein” products are not
truly hypoallergenic. The efficacy of any novel protein to reduce symptoms associated
with food hypersensitivity is the result only of its novel aspect. In other words, no intact
animal or plant protein is known to be less allergenic compared to another. In fact,
prolonged exposure to the “novel-protein” has the potential to induce a new allergic
response. Because there may be a genetic component that may predispose an animal
to have food hypersensitivity, the “novel-protein” strategy may eventually fail if the
animal develops a hypersensitivity to the new protein.
Using a modified protein, unlike the “novel-protein” strategy, offers a promising
approach to treating food hypersensitivity. Molecular modification of dietary proteins
can be used to alter the physical characteristics of the protein rendering it less able to
elicit an immune response. Because the modified protein approach is common practice
in human infant nutrition, Purina scientists believed that this approach could also be
applied to pet food in order to manage canine food hypersensitivity. Purina scientists
decided that defatted soy protein was excellent protein for such modification because
the size of the major allergens in soy protein are known and were then used to
determine the modification required to produce hypoallergenic soy protein. Additionally,
the amino acid composition of soy requires only minimal addition of other amino acids to
in order for the amino acid profile to be balanced for dogs. Purina scientists used a
molecularly modified soy protein with a molecular weight of 12,200 daltons, well below
the size of the known allergens in soy. Purina scientists then developed Purina
Veterinary Diets HA Hypoallergenic brand Formula, which was the first truly
hypoallergenic, single protein diet for dogs suffering from food hypersensitivity. Soy
protein antibodies did not recognize Purina Veterinary Diets HA Hypoallergenic
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brand Formula, indicating that its allergenicity was significantly reduced [Hannah et al.,
2000]. When Purina Veterinary Diets HA Hypoallergenic brand Formula was fed to
dogs suffering from inflammatory bowel disease (often associated with food allergies),
67% of the dogs had adequate clinical improvement with dietary treatment alone [Marks
and Laflamme, 1999]. Also, fecal scores improved from a mean of 42.5 to 91.7 (100 is
best score) after therapy. Purina Veterinary Diets HA Hypoallergenic brand Formula
provides complete and balanced nutrition for the growth of puppies and maintenance of
the adult dog. Thus, for dogs in these life stages, it can be used for the long-term
maintenance of allergic dogs and may also be used as an elimination diet to aid in the
diagnosis of food hypersensitivity and identification of offending allergens.
5
Purina’s Innovative Research Helps Companion Animals Fight the Bulge
Introduction
Obesity is a major health problem that affects not only humans, but companion
animals as well. Obesity, which is defined as an excess of body fat sufficient to result in
the impairment of health and/or body function, is the most common nutritional disorder
observed in dogs and cats. Similar to that observed in humans, obesity affects
approximately 25-30% of dogs and cats seen by veterinarians in the United States. The
excessive deposition of body fat in obese humans and companion animals is associated
with many health problems including diabetes mellitus [Mattheeuws et al., 1984, Nelson,
1990], hypertension (or high blood pressure) [Rocchini et al., 1987], musculoskeletal
problems [Edney and Smith, 1986], dermatitis [Buffington, 1994], respiratory problems
and gastrointestinal disorders [Scarlett and Donoghue, 1998].
Recognition of Obesity in Companion Animals
One of the major problems in obesity management in companion animals has
been the lack of a practical method for accurately assessing obesity. The quality of the
technique used to identify obese animals must be repeatable, reproducible and
predictable. A useful tool for the clinical assessment of obesity must meet these criteria
plus be easy to use and cost effective. One method, dual energy X-ray absorptiometery
(DEXA), can determine body fat and lean body mass of companion animals [Tool et al.,
1994]. While DEXA is an excellent research tool, it may not be practical to use in
veterinary practice due to equipment costs and other factors. The Purina Body
Condition System provides a semi-quantitative assessment of body composition.
While such systems have been used in production animals, there have been no
comparable widely accepted systems in use for dogs and cats until the development of
Purina’s.
Because of Purina’s experience in companion animal nutrition, health and care,
Purina scientists developed a 9-point Purina Body Condition System for both dogs
and cats [Laflamme, 1997, Laflamme, 1997]. The Purina Body Condition System
developed for dogs and cats is simple to use, requiring only intellectual addition to a
routine physical examination. It has been shown to be repeatable both within scorers
and between scorers. The accuracy of the Purina Body Condition System is similar
to that of other, more complex means of estimating body composition. And, the 9-point
Purina Body Condition System system is suitable for use as a clinical tool to
estimate body composition in both dogs and cats. It may be useful as a tool in obesity
management as well as in making recommendations for appropriate diets or feeding
management for all patients.
Traditional Approach to Dietary Management of Obesity
6
Historically, it was recommended that, in order to facilitate weight loss, humans
and companion animals be fed a calorie-restricted, low-fat diet. Many of these calorierestricted diets were also reduced in protein. Researchers, however, found that
although this diet facilitated rather rapid weight loss, it resulted in the excess loss of
lean body mass rather than fat mass, which is counterproductive in a long-term weight
maintenance program. Lean body mass is the primary determinant of basal energy
metabolism (minimum energy required to keep a resting, awake body alive) and
accounts for 95% of the animal’s metabolic rate [Roubenoff, 1993]. Moreover, basal
energy metabolism is generally higher in individuals with greater amounts of lean body
mass compared to those with large proportions of fat mass. Tissues, such as muscle,
liver, brain and kidney, show higher metabolic activity at rest and have high-energy
requirements. By restricting caloric intake without supplying an adequate amount of
dietary protein, basal energy metabolism decreases substantially, which can make
losing weight and long-term weight maintenance difficult. Preservation of lean body
mass is also important in helping to maintain protein turnover rates, which allow for the
rapid redistribution of amino acids to support the immediate manufacture of proteins
necessary for vital physiological functions such as immune function. A decrease in
protein turnover can impair immune function, which may leave the animal susceptible to
infection, injury and environmental stresses [Young and Marchine, 1990]. Thus,
preservation of lean body mass is an important component in both weight loss and longterm weight maintenance programs.
Protein-to-Calorie Studies in Dogs and Cats
Scientific research in humans has demonstrated that increasing the protein-tocalorie ratio of the calorie-restricted diet is an effective way to facilitate weight loss and
long-term weight maintenance. Increasing dietary protein in obese humans fed a very
low energy diet helps maintain lean body mass. Although much research had been
performed in human subjects, the hypothesis had not yet been tested in companion
animals. Because of Purina’s expertise and prior research on the amino acid and
proteins needs of companion animals, Purina scientists tested the efficacy of increased
dietary protein to spare lean body mass in companion animals fed for weight loss.
Purina scientists have conducted several weight loss studies using different breeds of
overweight dogs [Laflamme and Kuhlman, 1995, Laflamme et al., 1997, Hannah and
Laflamme, 1998]. More recently, Purina scientists studied forty-two overweight dogs
that were assigned to one of 3 dietary treatment groups and fed to achieve a rate of 1%
body weight loss per week until each dog reached an ideal body condition (body
condition score=5 using a 9 point system) [Hannah and Laflamme, 1998]. Each test
diet was similar except for the protein level (20%, 30% or 39% of calories). Overweight
dogs fed 20% of calories from protein lost approximately twice as much lean body mass
with less fat mass loss compared to dogs fed 30% or 39% calories from protein. Thus,
dietary protein should be provided at an optimal level in order to achieve weight loss
goals without compromising lean body mass.
In cats, Purina has also conducted several studies over the years to determine
the effect of dietary protein intake on lean body mass in cats during weight loss
7
[Laflamme and Jackson, 1995, Laflamme and Hannah, 1998]. In one study, sixteen
obese cats were energy restricted to achieve a loss of 1% body weight per week for a
study period of up to 6 months using two dry diets that differed only in the amount of
protein [Laflamme and Hannah, 1998]. The cats received one of the two isocaloric test
diets that consisted of either a low calorie diet with protein at 35% metabolizable energy
or a low calorie diet with an increased protein-to-energy ratio (protein = 45% of
metabolizable energy). While the total weight loss and rate of loss were very similar
between diets, the composition differed significantly. That is, the higher protein diet
limited the loss of lean body mass, while resulting in approximately 10% greater fat
mass loss. It was found that the obese cats fed protein at 35% of metabolizable energy
had a weight loss composed of 79% fat and 20% lean tissue. Alternatively, feeding
protein at 45% of metabolizable energy resulted in 88% fat loss and only 11% lean
tissue loss.
Practical Applications for Dogs and Cats
Such research, which demonstrated the importance of dietary protein in weight
loss and long-term weight maintenance programs, led to nutritional enhancements in
Purina Fit & Trim brand dog food to contain Purina Ulti-Pro Enhanced Protein
System. Purina Ulti-Pro Enhanced Protein System provides companion animals the
extra protein they need to help maximize protein turnover rates and maintain lean body
mass, especially during weight reduction. This product was tested to evaluate the
efficacy of the formula in overweight dogs. Purina collaborated with North Carolina
State University College of Veterinary Medicine to conduct an 8-week weight loss study
with 64 overweight, but otherwise healthy, dogs. Calorie allowances were calculated to
allow a 2% initial body weight loss per week. All dogs were fed a diet of Purina Fit &
Trim brand dog food and a choice of several Purina dog snacks. Ninety-three
percent of the dogs had a body condition score of 7 (on a 9-point scale) at the beginning
of the study. The dog owners were encouraged to increase their dog’s activity level and
keep a daily diary to monitor food intake, attitude and behavior, while feeding Purina
Fit & Trim brand dog food. Of the 56 dogs that completed the study, 96% lost weight.
The average weight loss was 6.7% of initial weight. Interestingly, owners were given a
before and after study survey which evaluated their relationship with their dog, feeding
habits, reasons for participation in the program, other pertinent issues as well as
opinions regarding the weight loss program itself. Most of the owners (73%) said it was
not difficult to keep their dogs on the weight loss program for eight weeks. This simple,
structured program that included a high protein, high fiber, low fat dog food made it easy
for owners of overweight dogs to change their behavior and made them optimistic about
maintaining the new weight of their dog.
8
Purina Demonstrates that Increasing Dietary Protein Spares Lean Body Mass in
Geriatric Dogs
Introduction
Traditionally, it was recommended that older dogs and cats be fed a lower
protein diet than younger animals because excess protein would cause kidney damage.
In the healthy dog and cat, however, there is no evidence that dietary protein levels
consistent with complete and balanced nutrition have adverse effects on kidney and
renal function. Protein restriction in senior dogs and cats, like humans, may not be
wise. In both humans and companion animals with increasing age, there is a
concomitant decrease in both lean body mass and protein turnover rates [Evans and
Campbell, 1993]. Along with the loss in lean body mass can be a loss in physical
strength and motor coordination [Castaneda et al., 1995], disability [Baumgartner et al.,
1996], immunocompetence [Castaneda et al., 1995] and increased rates of morbidity
and mortality [Baumgartner et al., 1996]. Older dogs and cats may not be as efficient in
metabolizing dietary protein compared to younger animals [Wannemacher and McCoy,
1966, Evans and Campbell, 1993]. Research has also shown that older dogs and cats
may actually require more dietary protein than their younger counterparts in order to
maintain their protein reserves and maximize protein turnover rates [Wannemacher and
McCoy, 1966].
Purina’s Studies in Geriatric Dogs
Purina research scientists studied twenty-six Pointers within the age range of 7-9
years that were randomly assigned to 16.5% and 45.6% protein diets according to
gender and body weight [Kealy, 1998]. After two years into the study, percent lean
body mass was directionally higher and percent lean body fat was directionally lower on
the high protein diet. At the two year time point, the aging Pointers fed a diet composed
of 16.5% protein had an average percent lean body mass of 71.1 and an average
percent body fat of 24.8 compared to 76.2% and 19.6%, respectively, in the aging
Pointers fed a diet consisting of 45.6% protein.
Practical Applications to Geriatric Companion Animals
Two papers were published summarizing energy requirements [Powanda, 1977]
and body composition [Reddy et al., 1976] of humans, dogs and cats. In dogs, 7 years
or older, a significant age-related decrease in maintenance energy requirements was
found. This decrease in maintenance energy requirements was associated with a
decline in physical activity levels and approximated a 20% decline in maintenance
energy requirements. If one assumes that the protein requirement (grams of protein/
kilogram of bodyweight/ day) of the senior dog is similar to maintenance and daily
energy intake is 20% less, then a senior dog diet should be formulated to contain 25%
of dietary calories from protein. Also, Purina scientists demonstrated that in a group of
Labrador Retrievers ranging from 2-13 years old, age-related decreases in lean body
9
mass and lean to fat ratio were detected, lending further support that a higher proportion
of dietary calories should be supplied by protein in geriatric dogs. Older dogs that
remain active do not experience a decrease in maintenance energy requirements
[Harper, 1998]. Thus, the dietary energy intake of older dogs should be individualized
to meet the animal’s specific needs.
10
Purina’s Extensive Research in Feline Nutrition Led to Revolutionary Diabetes
Diet
Introduction
Diabetes mellitus is a disease characterized by an alteration in cellular transport
and metabolism of glucose caused by an absolute or relative lack of insulin. Symptoms
of diabetes mellitus include frequent urination, excessive thirst, excessive hunger,
unexplained weight loss and diminished activity. Many tissues, such as skeletal
muscle, adipose tissue and cardiac muscle, rely on insulin stimuli to transport glucose
into their cells. Insulin is produced and released by the pancreatic beta cells in
response to increased concentrations of blood glucose. The circulating insulin is a
signal for the liver to store glucose as glycogen and decrease its glucose production.
Insulin also stimulates some tissues, such as skeletal muscle, to remove glucose from
the circulation in order to utilize it for energy and to replace glycogen stores. Insulin
interacts with these target tissues via cell surface receptors. In this manner, insulin
facilitates the uptake of glucose from the bloodstream into the target cell or tissue. In
the fasting state, when insulin levels are low, the liver releases glucose so that energy is
provided to the body, especially the central nervous system.
Physiology of Diabetes
In diabetes mellitus, blood glucose levels increase to abnormally high levels
because the pancreas has a decreased release of insulin or the insulin receptors on the
cell surfaces of certain body tissues are not functional or do not interpret the signal
properly. If target tissues do not receive a signal from insulin, then blood glucose levels
are elevated, skeletal muscle and liver are impaired in their ability to store glycogen,
and the liver continues to produce glucose.
In the stomach and small intestine, ingested protein is hydrolyzed into its
constituent amino acids. Digestion and absorption of ingested protein requires up to 8
hours. Protein in the intestine also stimulates the release of specific gut hormones that
are different from the hormones released after the ingestion of carbohydrates. In the
liver, amino acids are used for gluconeogenesis or protein synthesis. Nitrogen, from the
amino acids, is converted into urea and excreted into the urine. The nonessential
amino acids are primarily converted to glucose in the liver, while the essential amino
acids enter general circulation, taken up by tissues and used for the manufacture of new
protein or energy for skeletal muscles.
Feline diabetes usually occurs in overweight or middle-aged cats. Despite
physiological difference between dogs and cats, feline diabetes has been traditionally
treated in a manner similar to that in dogs and humans. That is, cats with diabetes were
treated with insulin plus a diet of complex carbohydrates and fiber to slow down the
digestive time, thereby, slowing the release of glucose into the bloodstream. While this
treatment was helpful for canine diabetes, it does not fully address the unique nutritional
needs of the diabetic cat.
11
Cats are carnivores and have much higher requirements for protein compared to
dogs. If too much protein in the diet is replaced with fiber, glucose production can be
adversely affected in cats. The hepatic enzymes in cats that breakdown proteins, are
continuously active allowing cats to handle high levels of proteins for energy or glucose
production [Kirk et al., 2000]. Unlike dogs and humans, cats cannot decrease the
activity of these enzymes when fed a low protein diet. Cats lack the enzyme
glucokinase, used by other mammals to help clear glucose from the bloodstream
[Kienzle, 1993]. Instead, they rely on a less efficient enzyme, hexokinase [Kienzle,
1993], to metabolize carbohydrate and to clear glucose from the bloodstream. This
results in slower clearance of glucose from the bloodstream [Hoenig and O’Brien, 1998].
Because cats are slower at metabolizing glucose compared to dogs can be a particular
disadvantage to the diabetic cat.
Practical Applications to Diabetic Cats
Purina’s extensive research in feline nutrition has led to the development of
Purina Veterinary Diets DM Diabetes Management brand Formula, the first feline
diet that works with the cat’s unique metabolism to help manage diabetes. Purina
Veterinary Diets DM Diabetes Management brand Formula was developed as a
result of collaborations between scientists at Purina and Heska Corporation (a leading
biotechnology company based in Fort Collins, Colorado), and incorporates Purina’s
research in proteins and understanding of the feline metabolism. Purina Veterinary
Diets DM Diabetes Management brand Formula was formulated with a high
concentration of dietary protein and low amounts of carbohydrates to help moderate
blood glucose levels. Heska Corporation conducted a clinical trial to test the
effectiveness of Purina Veterinary Diets DM Diabetes Management brand Formula
on 9 adult cats with naturally occurring diabetes mellitus. All cats were fed a high fiber,
moderate fat canned diet for 1-2 months during the standardization period. Afterwards,
all cats were transitioned onto a high protein, low carbohydrate canned diet for a 3month treatment period. The results showed that insulin was decreased in eight of the
9 cats when switched from the high fiber diet to the high protein diet, and insulin
injections were completely stopped in 1/3 of the cats. Regression analysis
demonstrated that exogenous insulin could be reduced by over 50% with no loss in
glucose control, as measured by serum fructosamine. This data was recently presented
at the Purina Nutrition Forum held October 19-22, 2000 in St. Louis, Missouri.
12
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