endocrine diseases e. simko wcvm zona glomerulosa -- aldosterone zona fasciculata - cortisol …...
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Endocrine diseases
E. Simko WCVM
Zona glomerulosa -- Aldosterone
Zona fasciculata - Cortisol …
Zona reticularis - Dihydroepiandrosterone
Adrenal medulla
Testosterone Estradiol
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- H2O
K+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- H2O
K+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 catsIncreased 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 productionInsufficient hormonal production
• Most commonly these disorders are due to proliferative lesions that are:
Functional and over produce hormonesCompressive 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 intermediaMost common in horsesSecond most common in dogs
Endocrinologically inactiveACTH secreting
• Endocrinologically inactive adenomasCommon in dogs, cats, and rodentsCompression Pituitary dysfunction, CNS signs
Pituitary adenomas
Endocrine diseases - Pituitary gland
E. Simko WCVM
• Pars intermedia origin• Lesions are secondary to:
Thalamic compressionProduction of beta endorphinProbably 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 tubulesUrine
Extracellular fluid
Bone
P
PTH +
Vit D +PTH +Ca
Ca
Calcitonin
Ca
Vit
D +
PT
H +
P
Cal
cito
nin
PT
H +
Endocrine diseases – Calcium and Phosphorus
E. Simko WCVM
• NeoplasiasLymphoma 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:
• HypoparathyroidismParathyroiditisIatrogenic – excision with thyroid glands
• Nutritional hyperphophatemia• Renal failure• Milk fever• C-cell thyroid neoplasia
Endocrine diseases – Calcium and Phosphorus
E. Simko WCVM
Primary: Parathyroid tumorsSecondary:
Renal failure Nutritional imbalance
Endocrine diseases – Calcium and Phosphorus
E. Simko WCVM
Secondary hyperparathyroidism:Nutritional imbalance ( P, Ca)
Renal failure
GFRVit D
HyperphosphatemiaHypocalcemia
Parathyroid hyperplasiaIncreased 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 CaPars intermedia in Eq
• Ca & P metabolism• Hypocalcemia and hypercalcemia• Hyperparathyroidism