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Protocol for Success in Managing Even Curing, Feline Diabetes
Copyright: 2004 Elizabeth Hodgkins DVM., Esq.
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This protocol consists of three indispensable parts: proper diet for the obligatory
carnivore diabetic, proper drug/hormone therapy (that is, the right insulin), and
proper use of that drug therapy and that diet to restore the patient to normal pancreatic
function.
First, some background on the evolution of the cat for context. Today's domestic
cat evolved from one or more small wild cat species in Africa and southern Europe.
The environment in which these progenitor cats developed was vegetation sparse and
small-prey-animal rich, causing this top-predator mammal to become dependant on
meat, and meats primary energy nutrient, protein and fat for sustenance. Over time
many of the pathways for carbohydrate metabolism that were developing to a high
degree in herbivorous and omnivorous species in more carbohydrate-rich environments
were discarded by the primitive cat. In fact, eventually this species rearranged
its systems for energy derivation so much that its metabolic systems began routinely
to use protein for energy without the switches for up and down regulation of that
protein use for energy (gluconeogenesis from amino acids) present in omnivores and
herbivores. That is, the cat will use dietary protein for energy production at a
high level EVEN in situations where dietary protein is very limited. During starvation,
the cat rapidly consumes its structural proteins for energy because of these evolutionary
choices made long ago. So the animal we find ourselves serving as veterinarians
is a “carbohydrate cripple” with a huge protein dependency!
Given the forgoing, it is not at all surprising that we now find many of our feline
patients fat, sluggish, and eventually, diabetic. For all of our good intentions
in bringing the cat into our homes as a pampered pet, we have done the species a
tremendous disservice in providing its members a diet far more appropriate for a
cow in a feedlot than an obligatory carnivore. Because of the food technology of
dry food production, dry cat foods are loaded with carbohydrate from cereal. This
carbohydrate is required to allow the extrusion process to take place; dry pet foods
are essentially breakfast cereal for pets with a little added meat meal for palatability.
Further, because this cereal undergoes processing at high heat and pressure during
extrusion, it becomes pre-digested and enters the pet’s bloodstream essentially
as sugar. Nothing in the cats evolutionary development could possibly prepare it
for a steady diet of this sugar laden “junk food.” Note: not all cereals are created
equal, of course. Some have much higher glycemic indices than others, meaning they
cause a greater rise in blood glucose when consumed and digested. Perhaps the most
offensive of all cereals used in pet foods is corn, (from which corn syrup is derived,
giving a good idea of how much sugar corn actually contains). Because it is plentiful
and cheap in this country, corn is one of the favorite dry pet food cereals used
by the industry. Sadly, even the most expensive, so-called premium dry pet foods
contain high amounts of this ingredient.
An additional consideration is the cat’s unique system of satiety signals from
food. Logically, because the cat evolved in an environment rich in protein and fat,
but deficient in carbohydrate, consumption of fat and protein evolved as the signal
to the cat that it may cease intake. Consumption of carbohydrate, however, has a
minimal effect on intake in the cat even as energy requirements are met and exceeded
with this nutrient. Thus not only is the cat relatively incapable of handling repetitive
substantial carbohydrate loads of the kind represented by dry cat food, it is also
unable to respond appropriately to that consumption with appetite satisfaction.
The end result is cats that overeat constantly flood their systems with glucose
overloads, and become obese. For a large number, their metabolic systems eventually
become overwhelmed by this highly unphysiologic diet and its unremitting stress
on the pancreas, resulting in diabetes.
- Diet
Because improper diet is the cause of type 11 diabetes mellitus in the cat, diet
must be the foundation of the management of this disease. Although the veterinary
profession has been conditioned to believe that high fiber dry diets are capable
of assisting in the management of feline diabetes, the reality is that this disease
has historically been extremely difficult to deal with BECAUSE of this mistaken
belief. The practice of using dry form, high fiber diets for our diabetic patients
is utterly in error. In fact, high fiber dry foods have two massive flaws. The first
is the high amount of carbohydrate in them (no, they are not immune from the requirement
of extruded foods for high cereal content) which promotes high blood glucose notwithstanding
the fiber contained in them. These diets are usually “low fat” as well as high fiber
and because of this, much of the usual fat in the formula has been replaced with
even more digestible carbohydrate than is present in regular formulas (in the highly
mistaken belief that it is dietary fat that makes cats fat).
The second serious flaw is the high fiber itself. As an obligatory carnivore,
the cats GI tract is short compared with that of the dog or humans. During evolution,
the cat's gastrointestinal tract adapted to the intake of calorie-dense, vegetation-poor
foods by reducing its length and ability to undertake prolonged digestion of fibrous
foods. High fiber foods ignore this fact, providing an unnatural burden on the feline
GI tract that results in excessive system bulk and reduced nutrient absorption.
Therefore, to manage feline type II diabetes, the patient MUST be provided a diet
that is high in protein, moderate-to-high in fat and ultra low in carbohydrate,
especially carbohydrate from extruded cereals and those with high glycemic indices,
like corn.
No feline diabetic should eat any type or brand of dry food. This includes Purina
DM dry (a high carbohydrate, corn-containing formula with no relationship whatsoever
to the canned version of this food) and Hills m/d dry (not only does this food contain
corn carbohydrate, it also has increased fiber). Allowable foods include canned
DM, Fancy Feast, and a number of other brands. For a comprehensive list of canned
cat foods and their nutrient levels, see the following listing of most major canned
foods: www.felinediabetes.com/cat_ food_ nutrition canned.htm nutrition. Look for
foods with low % of calories from carbohydrate.
Not only will a low carbohydrate canned food reduce the wide blood glucose swings
seen in feline diabetics, it will also reduce the pathologic overeating seen in
cats consuming dry foods that provide little or no sense of satiety.
- Proper insulin
Protamine zinc insulin is by far, the most effective form of insulin available
for use in the diabetic cat today. Beef and pork insulin molecules (beef is closer
than pork) are more closely analogous to endogenous feline insulin and give the
greatest response to the lowest dosages in the vast majority of feline diabetics.
It can to dosed at 12 hour intervals and, because canned cat food is supportive
of low blood glucose from diet, PZI allows good control of the diabetic ca, far
superior to that from NPH or Humulin insulins.
The starting point for insulin dosage is very empirical. Because you will be adjusting
it on a daily basis at the beginning, it is reasonable to start at a conservative
point and work up (or down, if possible) from there. For example, a diabetic patient
whose BG is 400 at 7AM should probably receive about 2.5-3.5 units to start. Generally
PZI peaks at about 6-8 hours, so another check at noon and then at 2-3 PM will likely
show you how low your initial dose will take the cat. If this patient is at 200
at noon, and 250 at 2 PM, you know you need more insulin now, because the cat has
reached and is ascending out of the peak action of the insulin. This process of
following the action of the insulin and administering additional amounts as needed
continues until the cat is spending most or all of the day at or below 100 dl/ml.
When this is achieved, smaller and smaller doses will be needed to accomplish this
level of control (because the cat's pancreas will be functioning better and better)
and it will become obvious that insulin can be discontinued. Almost all cat owners
can home test their cats with available human glucometers (I prefer the Freestyle
Flash brand) so that daily blood glucose monitoring is very feasible. This allows
very precise tailoring of the insulin dose to the cats “real-time” blood glucose
situation from day to day.
- Blood glucose control strategy
It is conventional wisdom within the veterinary profession that hypoglycemia in
the feline diabetic is to be feared more than any other eventuality. Thus, veterinarians
inadvertently strive to perpetuate their patients' diabetes, not realizing that
deliberately maintaining a patient's blood glucose in the hyperphysiological range
insures that the cat will never recover from its disease. While hypoglycemic seizures
are to be avoided, no question, it is not necessary to keep a patients blood glucose
above 200mg/dI, or even above 150, to accomplish this. Through its evolved physiology,
the cat LIKES to operate at blood glucose levels below 100! In fact, if we could
test our healthy patients without the “white coat effect” elevating their blood
glucose levels in our clinics, we would realize that most cats are perfectly happy
with BG levels around 60!). In nature, most of the cats’ blood glucose is glucose
produced by its liver from amino acids on an as needed basis. Large surges from
dietary carbohydrate intake, well tolerated by omnivores and herbivores, are essentially
unknown to the cat in the wild setting and clearly unwelcome as well.
A well known feline specialist at one of the large U.S. veterinary teaching hospitals
once observed to an audience that it was very easy to cause a transient diabetic
state in the cat by infusing IV glucose solution. This is, in fact, quite true and
highly relevant to the logic of managing the chronic diabetic. Elevated blood glucose|
is either toxic or suppressive (or both) of the feline endocrine pancreas, a fact
no doubt related to the almost vestigial nature of this function in a species that
evolved with little need to process and store dietary carbohydrate.
Therefore, the objective of managing the feline diabetic is to assist the cat's
endocrine pancreas to resume some or all of its prior function. This is visually
always possible in the cat that has been diabetic for a short period of time. As
a matter of fact, brand new diabetics often respond to a change of diet alone, and
never need insulin because the pancreas has not really gone dormant from chronic
hyperglycemia at that point. Immediate relief from dietary glucose overload can
allow immediate reactivation of the cat’s own pancreatic capabilities. The cat with
acute diabetes, however, like its more chronic colleagues, will NEVER be able to
consume high carbohydrate (dry) foods again for its entire life and its owners must
understand this. Such a cat will become diabetic very quickly once again if its
pancreas is stressed again by high sugar foods (or exogenous glucocorticoids, which
are extremely diabetogenic in the cat!).
In the more chronic diabetic, diet alone will often not provide immediate cure.
Those cats that have been diabetic a long time, especially those that have been
“managed” with dry foods and insulin types other than PZI, the road to cure will
be longer. This is only logical. The intoxication/suppression of the endocrine pancreas
in these cats has been prolonged and severe, and in some cases there may be no residual
function left at all. However, you will not be able to predict with certainty merely
from the duration of the cat's disease process whether or not a particular cat can
been cured. We have seen cats with relatively long histories respond well, in time
(several months), to proper regulatory efforts. Even those that never come completely
off insulin due to the chronicity of their disease and its improper management are
much healthier and more clinically normal on a low (in diet and PZI insulin at the
right dose than they have been previously.
For those cats that do not become euglycemic with diet alone. the objective
of PZI insulin therapy is to bring the cat into a normal range of blood glucose
(80-130) and keep it there! I cannot emphasize this enough. Because continual hyperglycemia perpetuates the
pancreatic suppression/toxicity that has caused the diabetes in the first place,
cure can only happen if the highly effective PZI tool is used to titrate the diabetic
cat into the normal range for glucose| in this species. In fact, the 80-130 range
is a bit high for the cat at rest without excitement. Most cats operate when relaxed
between 60-80! As long as you make increases in your insulin dose to achieve these
lower BG numbers gradually, you will not cause seizures in your patients. In dozens
of cats that I have put through this protocol, I have never caused a single one
to seizure, despite taking many well below 100 mg/dl. You must give up the fear
you have been taught about taking a diabetic cat into the normal BG range, or your
patients will always be diabetic. They will be healthier diabetics on step one and
step two alone, but without step three, and maintenance of step three for several
weeks or months until the patient demonstrates the ability to take over production
of insulin endogenously, the pancreas will never be released from its suppressed/intoxicated
site and will not begin to function again. On the other hand with step three added,
75-80% of your reasonably healthy diabetics will resume normal endocrine pancreatic
function and resume normal lives without drug support. A note about female type
II feline diabetics: type II diabetes is harder to induce in the female whether
the induction agent is diet or exogenous glucocorticoids or both. This is why 75%
or more of our diabetic patients are male, but the exact pathophysilogical explanation
for this is unknown. It is a fact that female diabetics do not respond to this protocol
by achieving cure as quickly as do males. Certainly the difference in susceptibility
to diabetes and the resistance to proper treatment for diabetes must be related
to the same physiologic difference between males and females, but until we know
what that is, the prognosis for cure is a little poorer for females than males.
I have cured many females, however, and even when they do not cure, they are much
healthier overall when they are managed with this protocol than otherwise.
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