Third Street Veterinary Hospital, PC
McMinnville, Oregon 97128
Office phone: (503) 472-9418
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 is 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
is a failure of the pancreas to regulate blood sugar.
The Types of Diabetes
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.
1. 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.
2. 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.
The Purpose of Insulin
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 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 is unable to get into the cells. It accumulates in the blood, setting in
motion a series of events that 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. It may rise to 250-300 mg/dl following a meal. However, diabetes is the only common disease
that will cause the blood glucose level to rise above 400 mg/dl. Some diabetic dogs will have a glucose level
as high as 800 mg/dl, although most will be in the range of 400-600 mg/dl.
To
keep the body from losing its needed glucose, the kidneys do not allow glucose
to be filtered out of the blood stream until an excessive level is
reached. 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.
What Diabetes Means to You
and Your Dog
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 may 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 5-7 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. This will
be explained in subsequent paragraphs.
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.
Treatment
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/d, CNM-OM, and CNM-DCO. If your dog is overweight,
Prescription Diet Canine r/d is fed until the proper weight is achieved, and then your dog is
switched to one of the others.
Your
dog's feeding routine is also important.
Some dogs prefer to eat several times per day. This means that food is left in the bowl at all times for free
choice feeding. Another way is to feed
twice daily, just before each insulin injection. If a two-meals-per-day feeding routine does not work for you dog,
it is still very important that you 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.
1) Insulin does not cause pain when it is
injected.
2) The injections are made with very tiny
needles that your dog hardly feels.
3) 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.
The
injection technique is as follows:
About Insulin. 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 and not
exposed to direct sunlight, although this is not advisable. Insulin is safe as long as it is used as
directed, but it should be kept out of reach of children.
Drawing up the Insulin. Have the syringe and needle, insulin bottle, and dog ready. Then, follow these steps:
1) Remove the guard from the needle, and draw
back the plunger to the appropriate dose level.
2) Carefully insert the needle into the insulin
bottle.
3) Inject air into the bottle; this prevents a
vacuum from forming within the bottle.
4) 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.
Injecting the Insulin. The steps to follow for injecting insulin are:
1) Hold the syringe in your right hand (switch
hands if you are left-handed).
2) 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).
3) 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. The needle should be
directed parallel to the backbone or angled slightly downward.
4) To inject the insulin, place your thumb on
the plunger and push it all the way into the syringe barrel.
5) Withdraw the needle from your dog's
skin. Immediately place the needle
guard over the needle and discard the needle and syringe.
6) Stroke your dog to reward it for sitting
quietly.
7) 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.
It
is neither necessary nor desirable to swab the skin with alcohol to
"sterilize" it. There are
four reasons:
1) 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.
2) 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.
3) The sting caused by the alcohol can make
your dog dislike the injections.
4) 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.
Monitoring
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 that 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 his 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:
1) 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.
2) Bring your dog to the hospital early in the
morning without giving it insulin.
3) A blood sample will be taken immediately,
then we will give insulin and feed your dog if it did not eat at home.
4) 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
Hypoglycemia
means low blood sugar. If it is below
40 mg/dl, it can be life threatening.
Hypoglycemia occurs under two conditions:
1) 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.
2) 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 per 10 pounds of body weight 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 or
on the weekend, call our emergency phone number for instructions.
SUMMARY OF
INSTRUCTIONS
1) Read and reread this material so that you
understand the specifics of proper regulation and how to recognize and treat
hypoglycemia.
2) Get the supplies for treatment. Your prescription will specify the type of
insulin and syringes. If you will be
using urine glucose tests strips, they should be purchased at a pharmacy.
3) Give the first injection of insulin of
_____units at about_________AM/PM.
4) Return for a glucose curve, no later than
8:00 a.m., on ____________. Feed your
dog that morning and immediately bring it to the hospital. Do not give insulin, but bring it with
you. (If it will take more than 30
minutes to drive to the hospital, call for instructions on feeding.)
5) Following regulation in the hospital,
measure the urine glucose 2 consecutive days, then twice weekly for the next 2
weeks. If glucose is not detected,
measure the glucose 2 consecutive days every other week.
6) If you are unable to test the urine for
glucose, return to our hospital in 2-4 days for a blood glucose test. This should be done about 5-8 hours after an
injection of insulin. If two injections
are given each day, be sure the test is done
before the evening injection.
7) Return to our hospital for a blood glucose
test in 1 month. This should be done
about 5-8 hours after an injection of insulin.
If two injections are given each day, be sure the test is done before the evening injection.