Endocrine Pancreatic Disorders

• Overview
• Diabetes Mellitus
• Gastrinoma
• Insulinoma

Thyroid Gland Disorders

• Hyperthyroidism
• Hypothyroidism

Adrenal Gland Disorders

• Hyperadrenocorticism
• Catecholamine-Secreting Adrenal Tumors
• Sex Hormone–Secreting Adrenal Tumors
• Hyperaldosteronism
• Hypoadrenocorticism

Pituitary Disorders

• Anatomy and Physiology
• Diseases of the Pituitary Gland

Disorders of Calcium Metabolism

• Calcium Homeostasis
• Approach to the Cat with Hypercalcemia
• Increased Parathyroid Hormone with Hypercalcemia
• Decreased Parathyroid Hormone with Hypercalcemia
• Normal Parathyroid Hormone with Hypercalcemia
• Other Causes of Hypercalcemia
• Treatment of Hypercalcemia
• Hypocalcemia

FIGURE 8-5. Diagnostic approach to hypoglycemia in dogs and cats. ACTH, Adrenocorticotropic hormone; ALT,alanine aminotransferase; CBC, complete blood count; SAP, serum alkaline phosphatase; US, ultrasound; WBC, white blood cell.



Diagnostic evaluation of hypercalcemia in dogs and cats.

The range of serum calcium and phosphorus concentrations for the more common causes of hypercalcemia and for hyperparathyroidism in dogs. HP, Hyperparathyroidism; 2°, secondary.

Range of serum calcium (Ca) and parathyroid hormone (PTH) concentrations for the more common disorders causing alterations in serum calcium or parathyroid gland function.

Diagnostic evaluation of hypocalcemia in dogs and cats. 

Diagnostic approach to persistent or inappropriate hyperglycemia in diabetics treated with insulin. 

Diagnostic approach to hyperlipidemia in the dog and cat.

Evaluation of cats with suspected hyperthyroidism based on history, clinical signs (i.e., weight loss, polyphagia, polyuria-polydipsia, hyperactivity, cervical mass) or laboratory findings (i.e., increased serum alkaline phosphatase [SAP], increased serum phosphorus).

Interpretation of thyroid-stimulating hormone (TSH) stimulation test in dogs. 
 

Endogenous plasma adrenocorticotropic hormone (ACTH) concentrations from clinically normal dogs, dogs with adrenal-dependent hyperadrenocorticism (adrenocortical carcinomas or adenomas), and dogs with pituitary-dependent hyperadrenocorticism.

Endogenous plasma adrenocorticotropic hormone (ACTH) concentrations in normal dogs, dogs with secondary adrenal failure, and dogs with primary adrenal failure.

Evaluation of patients with suspected hyperadrenocorticism based on history (polyuria-polydipsia, polyphagia, panting, weakness), physical examination (truncal alopecia, potbelly, calcinosis cutis, hepatomegaly), or laboratory findings (increased serum alkaline phosphatase [SAP], lymphopenia, eosinopenia, hypercholesterolemia, urinary tract infection). ACTH, Adrenocorticotropic hormone; PDH, pituitary-dependent hyperadrenocorticism; UCCR, urine cortisol : creatinine ratio.

Patterns of plasma cortisol responses during high-dose (0.1 mg/kg) dexamethasone suppression testing in dogs with pituitary-dependent or adrenal-dependent hyperadrenocorticism.

Adrenal Gland Disease

History and Physical Examination

Clinical Pathology and Diagnostic Testing

Possible Concurrent Abnormalities

Management

Adrenal Histopathology

Prognosis

Pheochromocytomas

Thyroid Disease

Diabetes Mellitus

History and Physical Examination

Clinical Pathologic and Diagnostic Testing

Treatment

Prognosis

Pancreatic Islet Cell Tumors

Etiology

Pathophysiology

Clinical Features

Clinical Pathologic Abnormalities

Differential Diagnoses for Fasting Hypoglycemia

Diagnostic Approach

Diagnostic Imaging

Management of Islet Cell Tumors

Histopathology

Prognosis

Although veterinary clinicians commonly rely on panels of laboratory tests with individual results flagged when abnormal, care should be taken in interpreting normal test results as well.  There are several examples of this in evaluating patients with endocrine disease.  The finding of a normal leukogram (absence of a stress leukogram) can be indicative of adrenal insufficiency in dogs, and this disorder can be especially elusive when there are no overt indicators of mineralocorticoid deficiency.  

Cats with hyperthyroidism can have normal serum thyroid hormone concentrations, normal hematocrits, and normal serum concentrations of creatinine despite the presence of disease that affects these parameters.  A normal serum phosphorus concentration, in the face of azotemia, isosthenuria, and hypertension can point a clinician toward a diagnosis of primary hyperaldosteronism rather than primary renal disease.  A normal serum parathyroid hormone concentration in the face of hypercalcemia is inappropriate and can indicate the presence of primary hyperparathyroidism.  Similarly, hypoglycemia accompanied by a normal serum insulin concentration can be found in cases of hyperinsulinism.  These normal findings in abnormal patients, and their mechanisms, are reviewed.

FIGURE 9-3. A, A canine rectal scraping showing a macrophage with numerous engulfed yeasts. These are Histoplasma capsulatum. B, A canine rectal scraping that shows inflammatory cells and spherical organisms with a clear halo. The organisms are Prototheca.