Diabetes mellitus is one of the most frequent chronic diseases in small animal clinics, being especially frequent in females and in adult individuals (with an average age of 7-9 years). Despite the fact that it is an incurable disease, with the commitment of caregivers and proper management of treatment, diabetic dogs can enjoy a good quality of life.
If you are interested in learning more about diabetes mellitus in dogs, its symptoms and treatment, join us in the next article on our site in which we also explain the diagnosis of this chronic disease.
What is diabetes mellitus in dogs?
Diabetes mellitus is an endocrine disease characterized by a state of persistent hyperglycemia (elevated blood glucose levels), the which is caused by a deficiency in the production of insulin or by factors that prevent its action. To better understand how this disease develops, we will briefly explain its pathogenesis.
Insulin is a hormone secreted by the pancreas in response to the presence of glucose in the blood. When blood glucose levels rise, the pancreas releases insulin to allow glucose to enter cells and be used for energy. However, when for reasons that we will see below there is a deficiency in insulin production or there are factors that prevent its action, glucose accumulates in the blood producing a state of hyperglycemia.
When the blood glucose concentration exceeds the so-called “renal threshold”, glucose is excreted in the urine (glycosuria). At the same time, the absolute or relative lack of insulin causes the tissues to have a limited access to glucose, and therefore needbreak down the body's protein and fat reserves to obtain the energy they need.
Causes of diabetes mellitus in dogs
Diabetes is usually a multifactorial disease, that is, it is usually a process conditioned by various factors. Specifically, the causes of diabetes mellitus in dogs can be primary or secondary.
- Primary causes: those that affect the pancreas itself. This group includes pancreatitis, exocrine pancreatic insufficiency and immune-mediated insulitis, among others. To learn more about exocrine pancreatic insufficiency in dogs: symptoms and treatment, don't hesitate to read this article that we recommend.
- Secondary causes: those that do not directly affect the pancreas, such as glucocorticoid treatment, high levels of progesterone, obesity, infection or inflammation chronic and azotemia. Check out this post about the Consequences of obesity in dogs
Types of diabetes mellitus in dogs
In dogs, three distinct types of diabetes mellitus are recognized:
- Type I diabetes mellitus: also known as insulin-dependent diabetes. It is the most common form of diabetes mellitus in dogs. It occurs as a consequence of a primary injury to the pancreas that destroys the pancreatic cells responsible for insulin synthesis. As a consequence, there is an absolute deficiency of insulin in the body. This type of diabetes is irreversible, which means that patients require lifelong insulin treatment.
- Type II diabetes mellitus: also known as non-insulin dependent diabetes. Although it can occur in dogs, it is more common in cats. In this case, individuals are capable of producing insulin, but there are factors (essentially obesity) that induce resistance to insulin in the tissues, which prevents for the hormone to exert its effect. The advantage of this type of diabetes is that is reversible
- Type III or secondary diabetes mellitus: is a type of diabetes that occurs when combines certain diseases (such as pancreatitis, Cushing's syndrome, and acromegaly) together with certain drugs (such as glucocorticoids or progestins). Do not hesitate to read this article on our site to find out more about Cushing's Syndrome in dogs: symptoms and treatment.
Symptoms of diabetes mellitus in dogs
The symptoms associated with diabetes mellitus in dogs are quite obvious, allowing handlers to detect the signs easily and go to the vet in the early stages of the disease.
Specifically, the clinical picture of diabetic patients is characterized by “the four P's”: polyuria, polydipsia, polyphagia and loss of weight. We explain these clinical signs in more detail below.
- Polyuria: increase in urine volume. As we explained at the beginning of the article, when the blood glucose level exceeds the "renal threshold", glucose is eliminated through the urine. Glucose acts as an osmotic diuretic, drawing large amounts of water with it and increasing the volume of urine.
- Polydipsia: increased water intake. The polyuria produced by the presence of glucose in the urine gives rise to compensatory polydipsia, in order to prevent dehydration of the animal. We leave you this other post about Polyuria and polydipsia in dogs: causes and what to do to learn more about the subject.
- Polyphagia: increased appetite. As the tissues are not capable of capturing glucose, a negative energy balance is produced that the animal tries to compensate by increasing food consumption.
- Weight loss: The lack of intracellular glucose leads the body to break down fat and protein stores for energy, which results in weight loss.
Furthermore, diabetes can lead to a number of complications as a result of long-term sustained hyperglycaemia. The main complications associated with diabetes mellitus in dogs are:
- Cataracts: lens opacity. It is the most common complication of diabetes mellitus in dogs. They are irreversible and can evolve rapidly. Do not hesitate to read more about Cataracts in dogs: symptoms, causes and treatment, here.
- Bacterial infections: Oral, urinary and skin infections are very common in diabetic dogs.
- Hepatic lipidosis: accumulation of fat in the liver that occurs as a result of the mobilization of reserves to obtain energy.
- Pancreatitis-Although pancreatitis is a cause of diabetes, it can also be a complication. This is because the mobilization of fat reserves gives rise to a state of hyperlipemia that can predispose to the appearance of acute pancreatitis. We leave you this other post on our site about Pancreatitis in dogs: symptoms, causes and treatment so you can learn more about the subject.
- Peripheral neuropathy: although it is more common in cats, it can also occur in dogs
- Glomerulopathies: this is a group of diseases that lead to a loss of the glomerular filtration membrane and its integrity.
- Diabetic Ketoacidosis: This is the most serious complication of diabetes mellitus. If not treated promptly, the death of the patient occurs as it implies an absolute deficiency of insulin.
Diagnosis of diabetes mellitus in dogs
The diagnostic plan for diabetes mellitus in dogs is based on the following points:
- Medical history: As we have mentioned, the most common signs of diabetes in dogs are polyuria, polydipsia, polyphagia and loss of weight.
- Blood analysis: hyperglycemia (>200 mg/dl) is detected in all diabetic animals. In the event that it is in a doubtful phase (180-200 mg/dl), the animal is considered to be prediabetic. In prediabetic or potentially diabetic animals, it is recommended to measure the levels of glycated proteins (fructosamine and glycated hemoglobin) that indicate glycaemia in recent weeks. In addition to hyperglycemia, hyperlipidemic fasting plasma, as well as increased liver enzymes GPT and alkaline phosphatase, can be seen in many diabetic patients.
- Urinalysis: When the renal threshold is exceeded, glucose will be detected in the urine (glycosuria). Although the animal has polyuria (increased urine volume), urine density is normal or even increased because the presence of glucose in the urine increases its osmolarity. In addition, ketonuria (presence of ketone bodies in the urine) and proteinuria (presence of protein in the urine) may be observed in some patients.
- Diagnosis by imaging: Given the large number of complications that can develop in diabetic patients, it is advisable to carry out diagnostic imaging tests (mainly X-rays and ultrasounds) to detect these complications early.
Treatment of diabetes mellitus in dogs
Diabetes mellitus is a chronic disease for which there is no curative treatmentHowever, with correct pathology management, diabetic dogs can live with a good quality of life. Therefore, it is essential to diagnose and control the disease as soon as possible, to reduce or eliminate clinical signs and delay the onset of complications.
In any case, it is essential that caregivers of diabetic dogs understand the disease, its risks and its treatment, since their collaboration will be essential to control the pathology. In fact, caregiver involvement is one of the most important factors determining treatment success or failure.
Specifically, the treatment of diabetic dogs is based on four fundamental pillars:
- Insulin: Diabetic dogs require lifelong insulin therapy, and unlike people, diabetic dogs Insulin cannot be replaced by any other compound. There are several types of insulin depending on their strength and the duration of their effect. In dogs, the first option is Caninsulin, a slow-acting insulin of porcine origin and structurally identical to canine insulin. It is administered subcutaneously, 2 times a day. To administer the dose, it is essential to use specific syringes of veterinary insulin, since if syringes for human medicine are used, important dosing errors can be made. Read this post on our site about Insulin for dogs: dosage, types and price.
- Regular diet and exercise: Diabetic dogs must have a special diet that helps, on the one hand, to regain lost weight and, on the other hand, to reduce postprandial hypoglycemia. Specifically, a diet low in fat (<15% fat), rich in fiber (15-22% fiber) and with normal protein levels (20% protein) should be administered. The ideal is to divide the ration into 2 meals a day and use a specific feed for diabetic dogs. It should be noted that you should always administer food first and then insulin, and adjust the insulin dose based on what the animal is eating (for example, if you only eat half the ration, only half the insulin dose should be given). We leave you this article with some Diets for dogs with diabetes, so you can learn more about the subject.
- Control of other diseases and concurrent processes: any pathological or even physiological process (such as oestrus or pregnancy) can cause a diabetic patient decompensates, since these phenomena can produce insulin resistance. Therefore, it is important to detect and treat these processes early to keep diabetes under control.
- Treatment regulation (revisions): the treatment of diabetes mellitus is dynamic and requires adjustment of the insulin dose throughout the life of the animal. For this reason, diabetic patients should attend periodic reviews in which a blood glucose curve will be performed and weight, polyuria, polydipsia and polyphagia will be controlled. Based on the results of these reviews, your insulin dose will be adjusted.
How to prevent diabetes mellitus in dogs?
The prevention of diabetes mellitus in dogs is not a simple matter, since in most cases the pathology is caused by processes that cannot be avoided. However, there are certain risk factors that must be taken into account to prevent the onset of diabetes mellitus as much as possible:
- Castration: High levels of progesterone can lead to insulin resistance. For this reason, castration is especially recommended in female dogs as a preventive measure for diabetes mellitus. In addition, in bitches in which the disease has already been diagnosed, castration is always indicated since it can reverse diabetes. Don't hesitate to read this article about Neutering a dog: price, postoperative period, consequences and benefits.
- Obesity: Preventing obesity through a balanced diet and regular physical exercise will prevent some of the causes of diabetes, such as pancreatitis. Check out this post about Exercise for obese dogs, here.
- Periodic veterinary check-ups: Through these check-ups prediabetic animals can be detected that require specific management to prevent diabetes from finally developing. These reviews are especially recommended in breeds predisposed to diabetes mellitus such as: terriers (particularly the West Highland terrier), poodle, dachshund, schnauzer and golden retriever.
