Diabetes insipidus in dogs: Symptoms, causes & treatment

When we think of diabetes in dogs, most of us think of diabetes mellitus, which relates to insulin and blood sugar regulation. However, another, less common form known as diabetes insipidus also exists. This rare endocrine disorder involves the antidiuretic hormone (ADH), which controls water balance in the body, and though it shares a name with diabetes mellitus, the two are very different conditions.

In this article, we’ll explore what diabetes insipidus is, what causes it in dogs, how to spot the symptoms, and the treatment options for managing this condition responsibly, ensuring a good quality of life for affected dogs.

What is diabetes insipidus?

Diabetes insipidus (DI), sometimes called "water diabetes," occurs when a dog's kidneys cannot conserve water properly. As a result, dogs experience intense thirst (polydipsia) and produce large volumes of very dilute urine (polyuria).

There are two main types of diabetes insipidus in dogs to be aware of:

• Central Diabetes Insipidus (CDI): Caused by insufficient production of ADH due to damage or disease affecting the hypothalamus or pituitary gland in the brain. Causes may include trauma, tumours, infections, or congenital defects.
• Nephrogenic Diabetes Insipidus (NDI): Occurs when the kidneys do not respond properly to ADH, despite normal or high hormone levels. This can result from genetic defects, side effects of some medications, infections, or metabolic diseases affecting kidney function.

What causes diabetes insipidus in dogs?

Diabetes insipidus rarely arises without an underlying cause. Conditions affecting hormone production in the brain, particularly vasopressin (ADH), or kidney function can contribute to DI:

• Brain injuries, tumours, infections, or congenital defects impacting the hypothalamus or pituitary gland
• Kidney conditions that reduce sensitivity to ADH
• Side effects of medications such as steroids or certain diuretics
• Metabolic or endocrine diseases like Cushing’s or Addison’s disease
• Hereditary risk in breeds like the Afghan hound puppies and German shorthaired pointer puppies, which are thought to be more predisposed

Recognising the symptoms of diabetes insipidus

Affected dogs often show symptoms related to excessive water loss and compensatory drinking. Key signs include:

• Excessive thirst and drinking, sometimes leaving the water bowl empty multiple times daily
• Frequent urination with very large volumes of pale, diluted urine
• Accidents inside the house due to the increased need to urinate
• Potential dehydration if water intake is restricted or if the condition is not managed

Diagnosis of diabetes insipidus in dogs

If you notice these symptoms in your dog, especially if they have existing kidney or hormonal conditions, a veterinary assessment is crucial. Diagnosis typically involves:

• Physical examination and medical history review
• Urinalysis to assess urine concentration and electrolyte balance
• Blood tests for electrolyte levels and kidney function
• Water deprivation and ADH response tests to differentiate type of diabetes insipidus
• Imaging (e.g., MRI) if neurological causes are suspected

Treating and managing diabetes insipidus

While diabetes insipidus cannot be cured outright, management strategies can greatly improve your dog's quality of life. Treatment depends on the type of DI:

• Central DI: Hormone replacement therapy with desmopressin acetate, a synthetic ADH, often administered via eye drops, nasal spray, or orally.
• Nephrogenic DI: Treatment focuses on addressing underlying causes, such as stopping offending medications or treating infections. Thiazide diuretics may be prescribed to reduce urine volume paradoxically.
• Supportive care includes ensuring constant access to fresh water to prevent dehydration.

Regular veterinary check-ups are essential to monitor treatment effectiveness, adjust medication dosage, and manage any complications early.

Prognosis and responsible care

Most dogs with diabetes insipidus, when properly diagnosed and managed, can lead comfortable lives. Untreated DI risks dehydration and serious health problems, so early veterinary care is vital.

If you suspect your dog has diabetes insipidus, consult your vet promptly. Supporting your dog with ongoing care and appropriate treatment ensures the best possible outcome.

Remember to always seek puppies from reputable breeders or consider adopting to promote responsible ownership and healthy pets.