Endocrine Diseases in Dogs: Causes, Diagnosis & Treatment

A dog's endocrine system is critical to their overall health, regulating essential bodily functions through the release of hormones. When this system malfunctions or hormone levels become imbalanced, dogs may develop serious health conditions that require prompt veterinary attention. Hormones produced by glands like the thyroid and pancreas travel through the bloodstream to regulate metabolism, growth, and organ function. Disruption of these hormonal pathways can lead to various endocrine diseases affecting a dog's quality of life.

Understanding the Causes of Endocrine Diseases in Dogs

Endocrine diseases occur when there is either an overproduction or underproduction of hormones, or an interruption in their normal pathways. Causes can include damage to hormone-producing glands, tumours within or outside the endocrine system, or metabolic issues such as obesity.

• Tumours causing hormone overproduction, for example in adrenal or pituitary glands
• Damage or destruction of endocrine glands leading to hormone deficiency
• Hyperthyroidism resulting in excess thyroid hormone
• Hypothyroidism causing insufficient hormone production
• Obesity impacting hormone function and metabolic processes

Common Endocrine Diseases in Dogs

1. Hypothyroidism

Hypothyroidism is one of the most frequent endocrine disorders in dogs and results from insufficient production of thyroid hormone. This hormone regulates metabolism, so a deficiency can slow bodily functions.

Symptoms: Weight gain, lethargy, symmetrical hair loss especially on the trunk and tail (sometimes called "rat tail"), dry skin, and a cool skin temperature.

Treatment: This condition is usually managed with daily thyroid hormone replacement therapy, which dogs often respond well to.

2. Cushing's Disease (Hyperadrenocorticism)

Cushing's disease arises from excess cortisol production, frequently caused by tumours in the adrenal or pituitary glands.

Symptoms: Increased thirst and urination, panting, a pot-bellied abdomen, symmetrical hair loss, thinning skin, and increased appetite.

Treatment: Treatment options include medications to regulate hormone levels, surgical removal of tumours when possible, and radiotherapy.

3. Diabetes Mellitus

This metabolic disorder results from insufficient insulin production or the body's resistance to insulin, leading to elevated blood sugar levels.

Symptoms: Increased thirst, frequent urination, weight loss despite normal or increased appetite, and lethargy.

Treatment: Management requires insulin injections and careful dietary regulation to maintain blood glucose within normal limits.

4. Addison's Disease (Hypoadrenocorticism)

Although less common, Addison's disease is a serious condition caused by insufficient cortisol production.

Symptoms: Lethargy, weight loss, poor appetite, vomiting, and weakness.

Treatment: Lifelong hormone replacement therapy is essential to manage this condition effectively.

Diagnosing Endocrine Diseases

Early and accurate diagnosis relies on a detailed medical history, physical examination, and specific diagnostic tests to assess hormone levels and organ function.

• Complete blood count and biochemical profile
• Urinalysis
• Specific hormone assays (e.g., thyroid panel, cortisol levels)
• Imaging studies to detect tumours, such as ultrasound or MRI

Close collaboration with your vet ensures timely diagnosis and management to support your dog's health.

Treatment and Management

Treatment depends on the underlying cause of the hormone imbalance. For tumours, surgical removal may be possible, often in conjunction with a veterinary oncologist's care. Radiotherapy might also be advised.

In hormone deficiency cases, such as hypothyroidism or diabetes, hormone replacement like thyroid medication or insulin injections can effectively control symptoms. Regular veterinary follow-up is crucial to monitor treatment response and adjust doses to avoid side effects.

Living with and Managing Endocrine Diseases

Most dogs diagnosed with an endocrine disease will require ongoing treatment for life. Regular veterinary checks help monitor their condition ensuring the best possible quality of life. Sensitivity to changes in symptoms or behaviour by pet owners aids in early intervention for complications.

Responsible pet ownership includes providing a supportive environment, proper diet, and adherence to treatment plans prescribed by your vet.

Summary Table of Common Endocrine Diseases in Dogs