Endocrine diseases E. Simko WCVM Zona glomerulosa -- Aldosterone Zona fasciculata - Cortisol … Zona reticularis - Dihydroepiandrosterone Adrenal medulla TestosteroneEstradiol

Endocrine diseases Most common in dogs Clinical signs are predominantly due to lack of aldosterone E. Simko WCVM (Addison’s dz) Glomerular filtrate Epithelium of distal nephron Na + Cl - H2OH2O K+K+ H+H+

Endocrine diseases Most common in dogs Clinical signs are predominantly due to lack of aldosterone E. Simko WCVM (Addison’s dz) Glomerular filtrate Epithelium of distal nephron Na + Cl - H2OH2O K+K+ H+H+

Endocrine diseases - Hypoadrenocorticism Clinical presentation: Hyponatremia, hypochloremia, dehydration Hyperkalemia, acidosis Weakness, depression Bradycardia Hypovolemia, shock “Great pretender” E. Simko WCVM

Endocrine diseases - Hypoadrenocorticism Diagnosis: Blood chemistry: Na, Cl, K CBC: PCV ACTH stimulation – no cortisol response Necropsy (if animal died) E. Simko WCVM

Endocrine diseases E. Simko WCVM Most common in adult cats Increased incidence since 1970 Awareness and detection Change in life style of feline pets Etiology: Nodular thyroid hyperplasia Functional thyroid adenoma

Endocrine diseases - Hyperthyroidism Palpable mass(es) in one or both glands Increased basal metabolism Weight loss Hyperactivity Cardiomyopathy (Usually hypertrophic) Tachycardia Weakness when stressed Changes E. Simko WCVM

Endocrine diseases - Hyperthyroidism Clinical signs Palpable mass(es) in one or both glands Increased T4 & T3 blood concentration Diagnosis E. Simko WCVM

Endocrine diseases E. Simko WCVM Physiology and endocrinology is complex. (Independent review) Pathology is relatively simple resulting in: Excessive hormonal production Insufficient hormonal production Most commonly these disorders are due to proliferative lesions that are: Functional and over produce hormones Compressive and prevent normal production of hormones

Endocrine diseases - Pituitary gland E. Simko WCVM ACTH secreting - Most common in dogs – Cushing’s dz Adenomas of pars intermedia Most common in horses Second most common in dogs Endocrinologically inactive ACTH secreting Endocrinologically inactive adenomas Common in dogs, cats, and rodents Compression Pituitary dysfunction, CNS signs Pituitary adenomas

Endocrine diseases - Pituitary gland E. Simko WCVM Pars intermedia origin Lesions are secondary to: Thalamic compression Production of beta endorphin Probably due to ACTH Pituitary adenomas in horses

Endocrine diseases - Pituitary adenomas in horses E. Simko WCVM Thalamic compression results in: Intermittent pyrexia Hyperhidrosis (Increased sweating) Hirtuism (hypertrichosis) Polyphagia with huperglycemia and glycosuria Polyuria/polydipsia Production of beta endorphin Docility Diminished responsiveness to pain

Endocrine diseases - Pituitary gland E. Simko WCVM Clinical signs Glycosuria, glycemia ACTH / cortisol concentration MRI Diagnosis

Endocrine diseases – Calcium and Phosphorus E. Simko WCVM Parathyroid hormone Calcitonin (Thyroid C cells) Vitamin D Major regulators of Ca and P:

Endocrine diseases – Calcium and Phosphorus E. Simko WCVM Ca reabsorption from bone P excretion by kidney Formation of active Vit D by kidney Ca absorption from gut and reabsorption from renal tubules (minor) Ca PTH promotion of: serum Ca, serum P, renal excretion of P

Endocrine diseases – Calcium and Phosphorus E. Simko WCVM Ca Calcitonin : E. Simko WCVM Inhibition of PTH stimulated bone absorption Increased P excretion by kidney serum Ca, serum P

Endocrine diseases – Calcium and Phosphorus E. Simko WCVM Ca and P absorption by intestines May facilitate PTH action (1,25-dihydroxycholecalciferol)

Endocrine diseases – Calcium and Phosphorus E. Simko WCVM Intestinal Lumen Renal tubules Urine Extracellular fluid Bone P PTH + Vit D + PTH + Ca Calcitonin Ca Vit D + PTH + P Calcitonin PTH +

Endocrine diseases – Calcium and Phosphorus E. Simko WCVM Neoplasias Lymphoma Anal apocrine gland tumor (PTH-rP) Tumors metastatic to bone Hyperparathyroidism Parathyroid functional neoplasia Vitamin D toxicity Major clinical conditions:

Endocrine diseases – Calcium and Phosphorus E. Simko WCVM Major clinical conditions: Hypoparathyroidism Parathyroiditis Iatrogenic – excision with thyroid glands Nutritional hyperphophatemia Renal failure Milk fever C-cell thyroid neoplasia

Endocrine diseases – Calcium and Phosphorus E. Simko WCVM Primary: Parathyroid tumors Secondary: Renal failure Nutritional imbalance

Endocrine diseases – Calcium and Phosphorus E. Simko WCVM Secondary hyperparathyroidism: Nutritional imbalance ( P, Ca) Renal failure GFR Vit D Hyperphosphatemia Hypocalcemia Parathyroid hyperplasia Increased production of PTH Ca reabsorption from bone Osteodystrophy fibrosa

Describe basic structure, function and response to injury of CNS and PNS Define nomenclature of neuropathological terms and conditions Describe pathogenesis of Wallerian degeneration and axonal regeneration Define terminology of CNS traumatic injury We know NS 1:

We know NS 2: Cytotoxic, osmotic and vasogenic brain edema) Thiamine-responsive polioencephalomalacia of ruminants Thiamine deficiency in carnivores Lead Poisoning Salt Poisoning Toxin-induced vasogenic brain edema You should be able to define, describe pathogenesis, list lesions and know how to diagnose the following conditions:

We know NS 3: You should be able to define, describe pathogenesis, list lesions and know how to diagnose the following conditions: Meningitis ITEME Listeriosis TSE Rabies Distemper West Nile Viral encephalitis Equine protozoal encephalomyelitis

Define following conditions and give examples: Denervation atrophy Disuse atrophy Malnutrition atrophy Muscular hypertrophy Ischemic myopathy - Occlusion of the vascular system - External pressure on a muscle - Swelling of a muscle in a non-expandable compartment We know Muscle 1: E. Simko WCVM Describe mechanisms of: Muscular regeneration Muscular repair

We know Muscle 2: E. Simko WCVM You should be able to define, describe pathogenesis, list lesions and know how to diagnose the following conditions/diseases: Nutritional myopathy (White muscle disease) Toxic myopathy (Monensin toxicity) Exertional myopathy Gas gangrene and malignant edema Blackleg Botulism Tetanus Myasthenia gravis Masticatory muscle myositis

We know Skin dz: E. Simko WCVM See STUDY GUIDE FOR SKIN

We know Endocrine dz: E. Simko WCVM Endocrine dermatoses – see skin guide plus Adrenal neoplasms of ferrets Hypoadrenocorticism Hyperthyroidism Pituitary tumors ACTH secreting in Ca Pars intermedia in Eq Ca & P metabolism Hypocalcemia and hypercalcemia Hyperparathyroidism