Diabetes mellitus in dogs, cats and humans has a lot in common. However, the mechanism that leads to the development of diabetes and its manifestations often differ significantly depending on the type of animal. Consequently, the approaches to treatment are also not all the same. Therefore, we cannot blindly transfer everything we know about human diabetes to dogs.
So, for example, it is wrong to classify canine diabetes into type 1 and type 2 diabetes, as is the case in humans. In addition, many drugs that work well for humans work poorly or not at all on animals. There are other differences as well. So, we will only talk about dogs.
What’s going on normally
All cells in our body need glucose (“sugar”) as their main source of energy. Glucose enters the body through the intestines from food or from internal stores (liver glycogen, muscles, etc.). From the intestines or from internal stores to the places of consumption, glucose is carried by the blood. However, for most cells it is not enough for the blood to bring them glucose – it is also necessary for a hormone called insulin to transmit the corresponding signal to the cell, and the cell was able to perceive this signal. This hormone in the body is formed in the so-called islets of Langerhans in the pancreas.
So, after eating, glucose from the intestines enters the bloodstream and its level in the blood rises. The pancreas senses this increase and releases insulin into the bloodstream. The body’s cells pick up the insulin signal and carry glucose from the blood into the cytoplasm (inside the cells). The level of glucose in the blood drops, the cells feel “full”, the pancreas ceases to release insulin into the blood.
What Happens With Diabetes
In diabetes, one or both of the following occurs:
- The pancreas loses its ability to produce enough insulin
- Body cells lose their ability to perceive the insulin signal
In either case, the cells “do not understand” that there is already enough glucose in the blood, and they do not transfer it inside. As a result, blood glucose levels remain high while cells are “starving”. Hence, one of the symptoms of diabetes mellitus is high blood glucose.
Normally, the kidneys do not allow glucose to pass from the blood into the urine. However, when the blood glucose level rises above a certain limit, the kidneys fail and the glucose begins to pass through the urine. Thus, another symptom of diabetes mellitus appears – high glucose in the urine.
When there is a lot of glucose in the urine, it “pulls” water from the blood after it. As a result, the volume of urine increases and the animal begins to urinate a lot. Water is removed from the body, the body becomes dehydrated, the animal feels thirsty and begins to drink more. Hence the other two symptoms of diabetes: polyuria and polydipsia (drinking and urination).
Since cells cannot enter glucose inside, for the body this situation is essentially starvation. It includes compensation mechanisms: the animal feels hunger, and it starts eating more than usual (although this is not beneficial, since glucose remains in the blood and then leaves with urine), and internal energy reserves are mobilized. When the glycogen stores in the liver and muscles are no longer enough, the body begins to use the stores of protein and fat. Due to the breakdown of protein, muscle mass decreases. This is another symptom of diabetes mellitus – increased appetite along with weight loss.
With the massive breakdown of fats in the body, many ketone bodies are formed. Ketone bodies can also be found in urine. One of the ketone bodies is acetone, therefore, in animals with severe diabetes, you can notice the smell of acetone in their breath. In addition, blood acidity increases (pH decreases). This situation is called diabetic ketoacidosis and is critical. Without intensive treatment, it can lead to death in a matter of days, or even hours.
High blood sugar has a detrimental effect on many systems: diabetic cataract occurs (the lens of the eye becomes cloudy), due to damage to the nerve fibers, weakness of the hind limbs and a plantigrade gait appear (rarely in dogs). The presence of sugar in urine creates excellent conditions for bacterial growth, which is why cystitis is also a common complication of diabetes.
What dogs has diabetes?
It most commonly occurs in dogs between the ages of 7 and 9. Among dogs, unsterilized females are more likely to suffer from it.
What is the reason
In dogs, the main cause is hereditary predisposition.
Without delving into the mechanism of development of diabetes mellitus, we can say that in most cases it is impossible to establish the exact cause of its appearance. However, there are factors that predispose to diabetes and, together, can lead to it.
These factors are:
- Hormonal treatment
- The period of the first 1-2 months after estrus or pregnancy
- Other hormonal disorders.
How to make a diagnosis
To make a definitive diagnosis of diabetes mellitus, it is not enough to detect any one of the aforementioned signs, since there may be many other causes for each of them besides diabetes. So, for example, polyuria and polydipsia can be caused by chronic kidney failure, blood glucose can rise simply from stress, cataracts can simply be senile, and increased appetite along with weight loss can be caused by worms. For this reason, if you or your doctor suspect diabetes mellitus in an animal, it is often necessary to carry out a whole range of examinations, which are needed both in order to make an accurate diagnosis and in order to detect associated problems and complications. These examinations may include: blood tests (general, biochemical, acid-base balance, serial glucose measurements, hormone tests), urine tests, assessment of the amount of fluid consumed and urine output, X-rays, ultrasound, ECG.
What to do next
So, we know that our animal has diabetes mellitus, that is, the cells of the body do not enter glucose from the blood inside. In most cases, to overcome the lack of your insulin or low sensitivity to it, you need to administer insulin from outside.
It is impossible to predict in advance how much insulin will be required for a particular animal. However, based on the weight of the animal and previous experience, you can start with a specific dose, and then adjust the amount and frequency of insulin administration in accordance with the body’s response. For the most accurate and fastest dose selection, the best way is to build a glucose curve. To do this, blood glucose is measured every 1-2 hours after the administration of insulin for 8-24 hours. Thus, it is possible to find out at what interval after the administration of insulin begins to act, at what period does the peak of its action occur, how long and how strongly it acts.
The next step is to select the optimal feeding time for the animal. Depending on the type of insulin used (short, medium or long acting), on the type of food and on the individual characteristics of the animal, feeding simultaneously with the administration of insulin, some time after administration, fractional and frequent feeding in small portions or providing constant access may be recommended. to food.
Further supervision is carried out by the owner with regular monitoring by the attending physician. The condition of the animal may change, insulin sensitivity may increase or decrease, and co-morbid conditions may appear. For this reason, it is necessary to periodically come for follow-up examinations, conduct laboratory tests and sometimes repeat the construction of the glucose curve.
It is essential that the physician or assistant explains in detail and shows the owner how to store, how to draw up and how to administer insulin.
It is important to remember that the effect of too high blood glucose affects the body gradually, while a drop in glucose below normal levels (hypoglycemia) can lead to fatal consequences very quickly. Therefore, using insulin, the task is not to bring glucose to a normal level, but to keep it slightly above the upper limit of the norm. This way, we can be sure that we will not get hypoglycemia.
For the same reason, it is not as scary to “under-dose” insulin as to overdose it. Therefore, if you injected insulin, but were not sure that you got where you needed to (for example, you felt that the coat became wet at the injection site), or you do not know whether someone from your home has injected insulin before you, never re-inject insulin. It is better to skip the injection once than inject it twice by mistake.
Since there are often some difficulties in purchasing insulin from pharmacies, it is recommended that you always have one spare unopened pack of insulin at home. It is usually recommended to throw an opened package of insulin in 1.5-2 months, even if it is not used up completely.
Usually, immediately after a meal, glucose rises very much in the blood, and the body of a diabetic animal cannot cope with such a load. Therefore, the point of diabetic feeding is to ensure that glucose is transferred from the feed to the blood as slowly as possible. This is usually achieved by selecting specific sources of dietary fiber in the right proportion. In addition, feed must contain a limited amount of calories and sufficient protein. The best solution is feeding with special medicated feed. If, for any reason, this is not possible, you should discuss other options with your doctor. As we mentioned above, the frequency and time of feeding are adjusted individually.
As for the amount of feed consumed per day, it is very important to feed the animal in such an amount that it remains thin. Being overweight reduces the sensitivity of cells to insulin, which means it worsens diabetes.
When to sound the alarm
If the animal develops weakness, unsteady gait, trembling, loss of consciousness, convulsions, it is necessary to offer the animal to eat (if it is conscious), and if it refuses to feed, spread honey, sugar syrup or glucose solution on the mucous membrane of the mouth (tongue, gums) and contact a doctor immediately.
If your blood or urine glucose levels rise above their previous levels, you should contact your doctor within 1–2 days.
If the blood glucose level falls below 3 mmol / liter, it is necessary to offer the animal food (if it is conscious), and if it refuses to feed, smear honey, sugar syrup or glucose solution on the mucous membrane of the mouth (tongue, gums) and immediately contact a doctor.
If your urine glucose drops to zero and / or ketones appear in your urine, your blood glucose should be checked.
Diabetic ketoacidosis is a critical condition that usually appears after an animal has been suffering from diabetes for a long time. However, in some cases, diabetes can lead to ketoacidosis in a matter of days. As mentioned above, in this state, the body mobilizes large amounts of fat as an energy source. The liver of these fats forms ketone bodies, one of which is acetone. This leads to acidification of the blood and can lead to death in a short time.
Symptoms of diabetic ketoacidosis are: odor of acetone from the mouth, lethargy, refusal to eat, vomiting, diarrhea, rapid breathing, low temperature, coma.
If one or more of these symptoms appear, you should immediately contact your doctor.
Treatment of animals in a state of diabetic ketoacidosis consists primarily of the use of insulin and intensive care. Insulin in such cases is used not so much to lower blood glucose levels as to stop the production of ketone bodies in the liver. For this purpose, short-acting types of insulin are used, the drug is injected very often (every 1-2 hours) and under strict control of blood glucose levels. Droppers are needed in order to restore the water, acid-base and electrolyte balance in the body, in order to quickly remove ketone bodies from the body, and also to prevent blood glucose from falling below normal due to the introduction of insulin in large doses.
If it is not possible to stabilize the patient for a long time, the reason may be as follows:
- Incorrect intake and / or administration of insulin
- Inoperative insulin (expired or storage conditions have not been respected)
- Accelerated insulin metabolism (rapid excretion from the body)
- The Somoji effect (too high a dose of insulin can lead first to a sharp drop, and then to a strong and prolonged rise in glucose levels)
- Simultaneous use of other drugs (especially hormones)
- Changes in internal hormonal levels (sexual cycle in bitches, hyper- and hypo-adrenocorticism, acromegaly, etc.)
- Concomitant infections (in particular, cystitis, periodontal disease, dermatitis) and other diseases
- Obesity (see above)
- True insulin resistance
- Excess fat in the blood
- Antibodies against insulin.
What can be done besides insulin?
In most cases, no one can substitute insulin for the treatment of canine diabetes. However, there are a number of measures that can, if not negate, then at least significantly reduce the need for insulin in animals. For bitches, this is primarily sterilization (removal of the uterus and ovaries). If diabetes manifests itself during the first two months after estrus or pregnancy, then sometimes sterilization or simply the end of this period completely relieves the animal of the symptoms of diabetes. However, the predisposition to diabetes remains, and at any time it may reappear.
Another important point regarding fat animals is to reduce body weight to normal. It is also important to increase the physical activity of animals (longer walks and play with dogs).
You should switch to feeding with special medicinal feeds (Hill’s w / d, Royal Canin Diabetic, etc.).
Oral hypoglycemic agents
Glipizide (as well as glyburide and glibenclamide) – increases the production of insulin by the pancreas. This drug is not effective in treating canine diabetes. Metformin – increases tissue sensitivity to insulin, and also reduces the release of glucose from the body’s internal stores and glucose synthesis in the body.
Metformin could possibly help animals that still have some ability to produce insulin, but side effects (lethargy, loss of appetite, vomiting) limit its use. At this stage, additional research is required to draw conclusions about the appropriateness of its application.
Vanadium is an element found everywhere. It probably has insulin-like properties, and is also practically devoid of side effects, but, nevertheless, is ineffective in itself. Vanadium was studied in the form of dipicolinate. This form is not available for purchase. Vanadium sulfate is marketed as a vitamin supplement, but its effectiveness is unknown.
Chromium – in picolinate form enhances the effect of insulin in healthy dogs. However, this effect was not seen in diabetic dogs.
Acarbose – inhibits digestive enzymes responsible for breaking down starches (the main sources of glucose in the intestines). As a result, glucose is more gradually released into the intestines and a more even blood glucose level is maintained. The drug is expensive, has side effects (diarrhea, weight loss), so in dogs it is used only if insulin alone is not enough to control hyperglycemia.
Troglitazone – increases tissue sensitivity to insulin