Hormone disorders

Underactive thyroid (hypothyroidism)

The thyroid gland is a small organ in the neck area that produces the hormones thyroxine (T4) and triiodothyronine (T3). These hormones influence your dog's energy expenditure, body temperature, cardiovascular system and nervous system. If the thyroid gland produces too few hormones, this is known as an underactive thyroid or hypothyroidism.

The most common causes of hypothyroidism in dogs are

• An autoimmune disease in which the immune system attacks and destroys the thyroid gland (lymphocytic thyroiditis)
• An age-related regression of the thyroid gland (atrophy)
• A rare congenital malformation of the thyroid gland
• A tumor disease of the thyroid gland or the pituitary gland (hypophysis) that impairs hormone production
• A drug overdose or radiotherapy that damages the thyroid gland

The typical symptoms of hypothyroidism in dogs are

• Weight gain despite reduced food intake
• Lethargy, tiredness, reduced activity
• Hair loss, dry and flaky skin, increased susceptibility to infections
• Sensitivity to cold, low body temperature
• Slowed heartbeat, low blood pressure
• Behavioral changes such as aggressiveness, anxiety or depression

Hypothyroidism in dogs is diagnosed by a blood test that measures the concentration of thyroid hormones and other parameters. Treatment consists of lifelong administration of synthetic thyroid hormones in tablet form. The dosage must be adjusted individually and monitored regularly. With timely and consistent therapy, most dogs can lead a normal life.

Cushing's syndrome (hyperadrenocorticism)

Cushing's syndrome or hyperadrenocorticism is a disease in which the adrenal glands produce too much cortisol. Cortisol is a stress hormone that affects your dog's blood sugar levels, fat metabolism, immune system and blood pressure, among other things. If the cortisol level is permanently elevated, this can lead to various health problems.

The most common causes of Cushing's syndrome in dogs are

• A benign tumor of the pituitary gland (hypophysis) that produces too much adrenocorticotropic hormone (ACTH). This hormone stimulates the adrenal glands to produce cortisol. This case is called pituitary hyperadrenocorticism and accounts for about 80-85% of all cases.
• A benign or malignant tumor of one or both adrenal glands that autonomously produces cortisol. This case is referred to as adrenal-dependent hyperadrenocorticism and accounts for around 15-20% of all cases.
• Long-term administration of cortisone or other glucocorticoids as medication, for example to treat allergies, inflammation or autoimmune diseases. This case is known as iatrogenic Cushing's syndrome and is reversible when the medication is discontinued.

The typical symptoms of Cushing's syndrome in dogs are

• Increased thirst and urination
• Increased hunger and food intake
• Weight gain, especially in the abdominal area
• Hair loss, thin and brittle skin, poor wound healing
• Muscle weakness, atrophy, difficulty standing up
• Shortness of breath, coughing, heart problems
• Behavioral changes such as restlessness, nervousness or apathy

Cushing's syndrome in dogs is diagnosed by means of a blood test in which the concentration of cortisol and other hormones is measured. Imaging techniques such as X-rays, ultrasound or computer tomography are also used to assess the size and shape of the pituitary gland and adrenal glands. Treatment depends on the cause of Cushing's syndrome. In the case of pituitary hyperadrenocorticism, medication is usually administered to inhibit cortisol production. In the case of adrenal-dependent hyperadrenocorticism, surgery is usually performed to remove the affected adrenal gland. In the case of iatrogenic Cushing's syndrome, the medication is gradually reduced or replaced. The prognosis varies depending on the severity and concomitant diseases. With early and consistent therapy, many dogs can achieve a good quality of life.

Diabetes mellitus

Diabetes mellitus is a disease in which the blood sugar level is chronically elevated. This is because the pancreas produces too little or no insulin or the body's cells no longer respond to insulin. Insulin is a hormone that enables glucose to be transported from the blood into the cells. Glucose is the most important source of energy for your dog's body. If the glucose does not enter the cells, it remains in the blood and can lead to various complications.

The most common causes of diabetes mellitus in dogs are

• An autoimmune disease in which the immune system attacks and destroys the insulin-producing cells of the pancreas (type 1 diabetes)
• A genetic predisposition, obesity, age or other factors that lead to reduced insulin action or production (type 2 diabetes)
• Inflammation or a tumor of the pancreas that impairs insulin production
• A hormonal disorder such as Cushing's syndrome or hyperthyroidism that increases blood sugar levels
• Medication such as cortisone or other glucocorticoids that increase blood sugar levels

The typical symptoms of diabetes mellitus in dogs are

• Increased thirst and increased urination
• Increased hunger and food intake
• Weight loss despite good food intake
• Fatigue, weakness, reduced activity
• Vomiting, diarrhea, loss of appetite
• Urinary tract infections, skin infections, poor wound healing
• Cataracts (cataracts), blindness

Diabetes mellitus in dogs is diagnosed by means of a blood test in which the blood sugar level and other parameters are measured. A urine test is also carried out to determine the glucose content in the urine.