Endocrine Diseases

I.      The Adrenal Glands

1.     Adrenal Cortex

A.     Hyperadrenocorticism (Cushing’s disease) 

Hyperadrenocorticism may be the most frequent endocrinopathy in adult to aged dogs but is infrequent in other domestic animals. For more information click here or call your veterinarian.

  1. B.      Hypoadrenocorticism (Addison’s disease)

A deficiency in adrenocortical hormones is seen most commonly in young to middle-aged dogs. The disease may be familial in Standard Poodles, Bearded Collies, and Portuguese Water Dogs. For more information click here or call your veterinarian. 

2.     Adrenal Medulla

The adrenal medulla, although apparently not essential to life, plays an important role in response to stress or hypoglycemia. Pheochromocytomas may develop in dogs. These secrete epinephrine, norepinephrine, or both. For more information click here or call your veterinarian.

    II.      The Pancreas

1.     Diabetes Mellitus 

Diabetes mellitus is a chronic disorder of carbohydrate metabolism due to relative or absolute insulin deficiency. Most cases of spontaneous diabetes occur in middle-aged dogs and cats. For more information click here or call your veterinarian.

      2.     Functional Islet Cell Tumors 

The most frequent pancreatic islet tumor is an islet cell carcinoma derived from insulin-secreting β cells. These neoplasms frequently are hormonally active and secrete excessive amounts of insulin, which causes hypoglycemia. For more information click here or call your veterinarian.

      3.     Gastrin-secreting Islet Cell Tumors 

Gastrinomas of the pancreas have been reported in humans, dogs, and a cat. For more information click here or call your veterinarian.

 III.      The Parathyroid Glands and Disorders of Calcium Metabolism

      1.     Hypercalcemia in Dogs and Cats

 

  1. A.     Hypercalcemia of Malignancy 

Malignancy is the most common cause of persistent hypercalcemia in dogs and is a common cause in cats. For more information click here or call your veterinarian.

  1. B.      Hypercalcemia Associated with Hypoadrenocorticism 

Mild hypercalcemia (≤15 mg/dL) has been reported in up to 30% of dogs with hypoadrenocorticism (Addison’s disease). For more information click here or call your veterinarian.

  1. C.     Renal Failure

In cats, chronic renal failure (usually associated with chronic interstitial nephritis) appears to be the most common cause of hypercalcemia. For more information click here or call your veterinarian.

  1. D.     Primary Hyperparathyroidism 

Primary hyperparathyroidism results from excessive secretion of PTH by one or more abnormal (usually neoplastic) parathyroid glands. It is relatively rare in dogs and cats. For more information click here or call your veterinarian.

  1. E.      Other Causes of Hypercalcemia 

 

    1. a.      Hypervitaminosis D

Vitamin D toxicity refers to the effects of excessive intake of bioactive metabolites of vitamin D. For more information click here or call your veterinarian.

    1. b.      Granulomatous Disease

Hypercalcemia associated with granulomatous disease arises from an alteration of endogenous vitamin D metabolism. For more information click here or call your veterinarian.

    1. c.      Idiopathic Hypercalcemia of Cats

In recent years, a hypercalcemic syndrome in cats has emerged. Affected cats range in age from 2-13 yr, with no gender predilection. For more information click here or call your veterinarian.

    1. d.      Houseplants

Certain houseplants (e.g., Cestrum diurnum [the day-blooming jessamine], Solanum malacoxylon, Triestum flavescens) may contain a substance similar to vitamin D that may cause hypercalcemia when ingested. For more information click here or call your veterinarian.

    1. e.      Osteolytic Lesions

Hypercalcemia resulting from tumor invasion or metastasis to bone develops very rarely in animals. For more information click here or call your veterinarian.

2.     Hypocalcemia in Dogs and Cats

  1. A.     Hypoparathyroidism 

Hypoparathyroidism is a metabolic disorder characterized by hypocalcemia and hyperphosphatemia and either transient or permanent PTH insufficiency. The spontaneous disorder is uncommon in dogs and rarely reported in cats. For more information click here or call your veterinarian.

  1. B.      Other Causes of Hypocalcemia 

 

    1. a.      Renal Disease

Chronic renal failure is probably the most frequently encountered cause of hypocalcemia For more information click here or call your veterinarian.

    1. b.      Hypoproteinemia

Animals with hypoalbuminemia may be hypocalcemic because of a decrease in the protein-bound fraction of calcium, but the ionized calcium fraction may remain normal. For more information click here or call your veterinarian.

    1. c.      Pancreatitis

Hypocalcemia, when it occurs in animals with pancreatitis, is usually mild and subclinical. For more information click here or call your veterinarian.

    1. d.      Puerperal Tetany

Puerperal tetany (eclampsia) is an acute, life-threatening disease caused by an extreme fall in circulating calcium concentrations in the lactating bitch or queen. For more information click here or call your veterinarian.

    1. e.      Phosphate Enema Toxicity

Hypertonic sodium phosphate (e.g., Fleet®) enemas may result in severe biochemical abnormalities, especially when administered to dehydrated cats with colonic atony and mucosal disruption. For more information click here or call your veterinarian.

    1. f.       Chelating Agents

EDTA (ethylenediaminetetraacetic acid), citrated blood, and oxalic acid (a metabolite of the ethylene glycol in antifreeze) all complex calcium and can cause hypocalcemia. For more information click here or call your veterinarian.

  IV.      The Pituitary Gland

    1.     Hyperadrenocorticism 

Functional tumors in the pituitary gland, derived from corticotroph (ACTH-secreting) cells, result in a clinical syndrome of cortisol excess. This disease is common in dogs but not other species. For more information click here or call your veterinarian.

    2.     Nonfunctional Pituitary Tumors 

These tumors are uncommon in most species. Chromophobe adenomas appear to be endocrinologically inactive, but they may cause compression atrophy of adjacent portions of the pituitary gland and extend into the overlying brain. For more information click here or call your veterinarian.

    3.     Adult-onset Panhypopituitarism 

Endocrinologically inactive, nonfunctional pituitary tumors develop most commonly in adult to aged animals; there is no apparent breed predisposition. For more information click here or call your veterinarian.

    4.     Juvenile-onset Panhypopituitarism  (Pituitary dwarfism)

Pituitary dwarfism occurs most frequently in German Shepherds, but has been reported in other breeds. Dwarf pups are indistinguishable from normal littermates up to 2 mo of age. It is an inherited disease. For more information click here or call your veterinarian.

    5.     Diabetes Insipidus 

Central diabetes insipidus is caused by reduced secretion of antidiuretic hormone (ADH). It occurs infrequently in dogs and cats. For more information click here or call your veterinarian.

    6.     Feline Acromegaly 

Acromegaly, or hypersomatotropism, results from chronic, excessive secretion of growth hormone in the adult animal. For more information click here or call your veterinarian.

     V.      The Thyroid Gland

    1.     Hypothyroidism 

In hypothyroidism, impaired production and secretion of the thyroid hormones result in a decreased metabolic rate. This disorder is most common in dogs but also develops rarely in cats. For more information click here or call your veterinarian.

    2.     Non-neoplastic Enlargement of the Thyroid Gland (Goiter)

Non-neoplastic and noninflammatory enlargements of the thyroid gland develop in all domestic mammals. The major causes of goiter include iodine deficiency, goitrogenic substances, dietary iodine excess, and inherited enzyme defects in the biosynthesis of thyroid hormones. For more information click here or call your veterinarian.

    3.     Hyperthyroidism 

Excessive secretion of the thyroid hormones, T4 and T3, results in signs that reflect an increased metabolic rate and produces clinical hyperthyroidism. It is most common in middle-aged to old cats but also develops rarely in dogs. For more information click here or call your veterinarian.

  VI.      Neuroendocrine Tissue Tumors

1.     Adrenal medulla; Pheochromocytomas

These tumors of chromaffin cells are almost always located in the adrenal glands. They are the most common tumors in the adrenal medulla of animals; they develop most often in dogs. For more information click here or call your veterinarian.

    2.     Chemoreceptor organs

Although chemoreceptor tissue appears to be widely distributed in the body, tumors develop principally in the aortic and carotid bodies. These tumors are found primarily in dogs and rarely in cats. For more information click here or call your veterinarian.