DIABETES MELLITUS IN DOGS
There are two forms of diabetes in dogs:
diabetes insipidus and diabetes mellitus. Diabetes insipidus is a very rare disorder that
results in failure to regulate body water content. Your dog has the more common type of
diabetes: diabetes mellitus. This is a fairly common disorder and is most often seen in
dogs 5 years of age or older. There is a congenital form that occurs in puppies, but this
is not common. Diabetes mellitus is a disease of the pancreas. This is a small but vital
organ that is located near the stomach. It has two significant populations of cells. One
group of cells produces the enzymes necessary for proper digestion. The other group,
called beta-cells, produces the hormone called insulin. Simply put, diabetes mellitus a
failure of the pancreas to regulate blood sugar.
Some
people with diabetes take insulin shots, and others take oral medication. Is this true
for dogs?
In humans, two types of diabetes mellitus
have been discovered. Both types are similar in that there is a failure to regulate blood
sugar, but the basic mechanisms of disease differ somewhat between the two groups.
Type I, or Insulin Dependent Diabetes
Mellitus
, results from total or near-complete destruction of the beta-cells. This
is the only type of diabetes known in dogs. As the name implies, dogs with this type of
diabetes require insulin injections to stabilize blood sugar.
Type II, or Non-Insulin Dependent
Diabetes Mellitus
, is different because some insulin-producing cells remain.
However, the amount produced is insufficient, there is a delayed response in secreting it,
and the tissues of the dogs body are relatively resistant to it. People with this form may
be treated with an oral drug that stimulates the remaining functional cells to produce or
release insulin in an adequate amount to normalize blood sugar. Because Type II diabetes
does not occur in dogs, oral medications are not appropriate for treating diabetic dogs.
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The role of insulin is much like that of a
gatekeeper: it stands at the surface of body cells and opens the door, allowing glucose to
leave the blood stream and pass inside the cells. Glucose is a vital substance that
provides much of the energy needed for life, and it must work inside the cells.
Without an adequate amount of insulin, glucose in unable to get into the cells. It
accumulates in the blood, setting in motion a series of events which can ultimately prove
fatal. When insulin is deficient, the cells become starved for a source of energy. In
response to this, the body starts breaking down stores of fat and protein to use as
alternative energy sources. As a consequence, the dog eats more; thus, we have weight loss
in a dog with a ravenous appetite. The body tries to eliminate the excess glucose by
excreting it in the urine. However, glucose (blood sugar) attracts water; thus, urine
glucose takes with it large quantities of the body's fluids, resulting in the production
of a large amount of urine. To avoid dehydration, the dog drinks more and more water.
Thus, we have the four classical signs of diabetes:
CLASSICAL SIGNS OF DIABETES MELLITUS:
Weight loss, Ravenous appetite, Increased water consumption, Increased urination
The diagnosis of diabetes mellitus is
based on three criteria: the four classical clinical signs, the presence of a persistently
high level of glucose in the blood stream, and the presence of glucose in the urine. The
normal level of glucose in the blood is 80-120 mg/dl (4.4-6.6 mmol/L). It may rise to
250-300 mg/dl (13.8-16.7 mmol/L) following a meal. However, diabetes is the only common
disease that will cause the blood glucose level to rise above 400 mg/dl (22 mmol/L). Some
diabetic dogs will have a glucose level as high as 800 mg/dl (44 mmol/L), although most
will be in the range of 400-600 mg/dl (22-33 mmol/L). To keep the body from losing its
needed glucose, the kidneys do not allow glucose to be filtered out of the blood stream
unless very high levels of glucose are circulating in the blood. This means that dogs with
a normal blood glucose level will not have glucose in the urine. Diabetic dogs, however,
have excessive amounts of glucose in the blood, so it will be present in the urine.
For the diabetic dog, one reality exists:
blood glucose cannot be normalized without treatment. Although the dog can go a day or so
without treatment and not get into a crisis, treatment should be looked upon as part of
the dog's daily routine. Treatment almost always requires some dietary changes and
administration of insulin. As for the owner, there are two implications: financial
commitment and personal commitment. When your dog is well regulated, the maintenance costs
are minimal. The special diet, insulin, and syringes are not expensive. However, the
financial commitment is significant during the initial regulation process and if
complications arise.
Initially, your dog will be hospitalized
for a few days to deal with the immediate crisis and to begin the regulation process. The
"immediate crisis" is only great if your dog is so sick that it has quit eating
and drinking for several days. Dogs in this state, called ketoacidosis, may require a week
or more of hospitalization with quite a bit of laboratory testing. Otherwise, the initial
hospitalization may be only for a day or two to get some testing done and to begin
treatment. At that point, your dog goes home for you to administer medication. At first,
return visits are required every 3-7 days to monitor progress. It may take a month or more
to achieve good regulation.
The financial commitment may again be
significant if complications arise. We will work with you to try and achieve consistent
regulation, but a few dogs are difficult to keep regulated. It is important that you pay
close attention to our instructions related to administration of medication, to diet, and
to home monitoring. Another complication that can arise is hypoglycemia, or low blood
sugar; if severe, it may be fatal. This may occur due to inconsistencies in treatment.
Your personal commitment to treating this dog is very important in maintaining regulation
and preventing crises. Most diabetic dogs require insulin injections once or twice daily.
They must be fed the same food in the same amount on the same schedule every day. If you
are out of town, your dog must receive proper treatment while you are gone. These factors
should be considered carefully before deciding to treat a diabetic dog.
Consistency is vital to proper management
of the diabetic dog. Your dog needs consistent administration of medication, consistent
feeding, and a stable, stress-free lifestyle. To best achieve this, it is preferred that
your dog live indoors. Although that is not essential, indoor living removes many
uncontrollable variables that can disrupt regulation. The first step in treatment is to
alter your dog's diet. Diets that are high in fiber are preferred because they are
generally lower in sugar and slower to be digested. This means that the dog does not have
to process a large amount of sugar at one time. The preferred diets are Prescription Diet
Canine w/dJ and CNM OMJ. If your dog is overweight, Prescription Diet Canine r/dJ is fed
until the proper weight is achieved, then your dog is switched to one of the others.
Your dog's feeding routine is also
important. The average dog prefers to eat about 10-15 times per day, one mouthful at a
time. This means that food is left in the bowl at all times for free choice feeding.
However, this is not the best way to feed a diabetic dog. The preferred way is to feed
twice daily, just before each insulin injection. If your dog is currently eating on a free
choice basis, please try to make the change. However, if your dog will not change or if
you have several dogs that eat in a free choice fashion, you may find that this change is
not practical. If a two-meals-per-day feeding routine will not work for you, it is still
very important that you find some way to accurately measure the amount of food that is
consumed.
-- The foundation for regulating blood
glucose is the administration of insulin by injection. Many people are initially fearful
of giving insulin injections. If this is your initial reaction, consider these points.
-- Insulin does not cause pain when it is
injected.
-- The injections are made with very tiny
needles that your dog hardly feels.
-- The injections are given just under the
skin in areas in which it is almost impossible to cause damage to any vital organ. Please
do not decide whether to treat your dog with insulin until we have demonstrated the
injection technique. You will be pleasantly surprised at how easy it is.
Insulin comes in an airtight bottle that
is labeled with the insulin type and the concentration. Before using, mix the contents. It
says on the label to roll it gently, not shake it. The reason for this is to prevent foam
formation which will make accurate measuring difficult. Some of the types of insulin used
in dogs have a strong tendency to settle out of suspension. If it is not shaken properly,
it will not mix well, and dosing will not be accurate. Therefore, the trick is to shake it
vigorously enough to mix it without creating foam. Since bubbles can be removed (as
described later), it is more important to mix it well than to worry about foam formation.
Insulin is a hormone that will lose its effectiveness if exposed to direct sunlight or
high temperatures. It should be kept in the refrigerator, but it should not be frozen. It
is not ruined if left out of the refrigerator for a day or two, although this is not
advisable. Insulin is safe as long as it is used as directed, but it should be kept out of
the reach of children.
Have the syringe and needle, insulin
bottle, and dog ready. Then, follow these steps:
Remove the guard from the needle, and draw
back the plunger to the appropriate dose level.
Carefully insert the needle into the
insulin bottle.
Inject air into the bottle; this prevents
a vacuum from forming within the bottle.
Withdraw the correct amount of insulin
into the syringe.
Before injecting your dog with the
insulin, check that there are no air bubbles in the syringe. If you get an air bubble,
draw twice as much insulin into the syringe as you need. Then withdraw the needle from the
insulin bottle and tap the barrel of the syringe with your finger to make the air bubble
rise to the nozzle of the syringe. Gently and slowly expel the air bubble by moving the
plunger upward.
When this has been done, check that you
have the correct amount of insulin in the syringe. The correct dose of insulin can be
assured if you measure from the needle end, or "0" on the syringe barrel, to the
end of the plunger nearest the needle.
Hold the syringe in your right hand
(switch hands if you are left-handed).
Have someone hold your dog while you pick
up a fold of skin from somewhere along your dog's back with your free hand (pick up a
different spot each day).
Quickly push the very sharp, very thin
needle through your dog's skin. This should be easy and painless. However, take care to
push the needle through only one layer of skin and not into your finger or through two
layers of skin. The latter will result in injecting the insulin onto your dog's haircoat
or onto the floor.
To inject the insulin, place your thumb on
the plunger and push it all the way into the syringe barrel.
Withdraw the needle from your dog's skin.
Immediately place the needle guard over the needle and discard the needle and syringe.
Stroke your dog to reward it for sitting
quietly.
Be aware that some communities have strict
rules about disposal of medical waste material so don't throw the needle/syringe into the
trash until you know if this is permissible. If it is not, we can dispose of them for you.
There are four reasons why it is neither
necessary nor desirable to swab the skin with alcohol to "sterilize" it.
Due to the nature of the thick hair coat
and the type of bacteria that live near the skin of dogs, brief swabbing with alcohol or
any other antiseptic is not effective.
Because a small amount of alcohol can be
carried through the skin by the needle, it may actually carry bacteria with it into the
skin.
The sting caused by the alcohol can make
your dog dislike the injections.
If you have accidentally injected the
insulin on the surface of the skin, you will not know it. If you do not use alcohol and
the skin or hair is wet following an injection, the injection was not done properly.
Although the above procedures may at first
seem complicated and somewhat overwhelming, they will very quickly become second nature.
Your dog will soon learn that once or twice each day it has to sit still for a few
minutes. In most cases, a reward of stroking results in a fully cooperative dog that
eventually may not even need to be held.
It is necessary that your dog's progress
be checked on a regular basis. Monitoring is a joint project on which owners and
veterinarians must work together.
Home Monitoring
Your part consists of two forms of
monitoring. First, you need to be constantly aware of your dog's appetite, weight, water
consumption, and urine output. You should be feeding a constant amount of food each day
which will allow you to be aware of days that your dog does not eat all of it or is
unusually hungry after the feeding. You should weigh your dog at least once monthly. It is
best to use the same scales each time. You should develop a way to measure water
consumption. The average dog should drink no more than 7 1/2 oz. (225 mL) of water per 10
pounds (4.5 kg) of body weight per 24 hours. Since this is highly variable from one dog to
another, keeping a record of your dog's water consumption for a few weeks will allow you
to establish what is normal for your dog. Another way to measure water consumption is
based on the number of times it drinks each day. When properly regulated, it should drink
no more than six times per day. If this is exceeded, you should take steps to make an
actual measurement. Any significant change in your dog's food intake, weight, water
intake, or urine output is an indicator that the diabetes is not well controlled. We
should see your dog at that time for blood testing.
The second method of home monitoring is to
determine the presence of glucose in the urine. If your dog is properly regulated, there
should be no glucose present in the urine. There are several ways to detect glucose in
urine. You may purchase urine glucose test strips in any pharmacy. They are designed for
use in humans with diabetes, but they will also work in the dog. A fresh urine sample
should be collected and tested with the test strip. If glucose is detected, the test
should be repeated the next two days. If it is present each time, we should see your dog
for a blood test.
You should keep a small container to catch
urine as the dog voids. A large amount of urine is not needed to test for urine glucose;
it is not necessary to catch the entire amount of urine. Because the female dog usually
squats to urinate, a shallow pan or dish may be placed under the hindquarters when she
begins to urinate. For male dogs, urine can be collected as soon as the dog lifts the leg
to void. Male dogs often urinate small amounts in several different places and most often
urinate on vertical objects, such as bushes and trees.
Monitoring of Blood Glucose
Determining the level of glucose in the
blood is the most accurate means of monitoring. This should be done about every 3-4 months
if your dog seems to be well regulated. It should also be done at any time the clinical
signs of diabetes are present or if glucose is detected in the urine for two consecutive
days. Timing is important when the blood glucose is determined. Since eating will elevate
the blood sugar for several hours, it is best to test the blood at least 6 hours after
eating. When testing the blood we want to know the highest and lowest glucose readings for
the day. The highest reading should occur just before an injection of insulin is given.
The lowest should occur at the time of peak insulin effect. This is usually 5-8 hours
after an insulin injection, but it should have been determined during the initial
regulation process. Therefore, the proper procedure is as follows:
Feed your dog its normal morning meal then
bring it to hospital immediately. If you cannot a get it to the hospital within 30
minutes, do not feed it. In that situation, bring its food with you.
Bring your dog to the hospital early in
the morning without giving it insulin.
A blood sample will be taken immediately,
then we will give insulin and feed your dog if it did not eat at home.
A second blood sample will be taken at the
time of peak insulin effect.
If your dog gets excited or very nervous
when riding in the car or being in the hospital, the glucose readings may be falsely
elevated. If this occurs, it is best to admit your dog to the hospital the morning (or
afternoon) before testing so it can settle down for testing the next day. Otherwise, the
tests give us limited information.
Hypoglycemia means low blood sugar. If it
is below 40 mg/dl (2.2 mmol/L), it can be life-threatening. Hypoglycemia occurs under two
conditions:
If the insulin dose is too high
.
Although most dogs will require the same dose of insulin for long periods of time, it is
possible for the dog's insulin requirements to change. However, the most common causes for
change are a reduction in food intake and an increase in exercise or activity. The reason
for feeding before the insulin injection is so you can know when the appetite changes. If
your dog does not eat, skip that dose of insulin. If only half of the food is eaten
just give a half dose of insulin. Always remember that it is better for the blood sugar
to be too high than too low.
If too much insulin is given
. This
can occur because the insulin was not properly measured in the syringe or because two
doses were given. You may forget that you gave it and repeat it, or two people in the
family may each give a dose. A chart to record insulin administration will help to prevent
the dog being treated twice.
The most likely time that a dog will
become hypoglycemic is the time of peak insulin effect (5-8 hours after an insulin
injection). When the blood glucose is only mildly low, the dog will be very tired and
unresponsive. You may call it and get no response. Within a few hours, the blood glucose
will rise, and your dog will return to normal. Since many dogs sleep a lot during the day,
this important sign is easily missed. Watch for it; it is the first sign of impending
problems. If you see it, please bring in your dog for blood testing. If your dog is slow
to recover from this period of lethargy, you should give it corn syrup (1 tablespoon by
mouth). If there is no response in 15 minutes, repeat the corn syrup. If there is still no
response, contact us immediately for further instructions. If severe hypoglycemia occurs,
a dog will have seizures or lose consciousness. This is an emergency that can only be
reversed with intravenous administration of glucose. If it occurs during office hours,
come in immediately. If it occurs at night, call the Pierce County Animal Emergency Clinic
for instructions.