LIFE“Smooth seas do not make skillful

sailors.”

-African proverb

DISEASES OF THE ADRENAL GLANDS

CUSHING’S DISEASE(__________________________)

ADDISON’S DISEASE(__________________________)

Adrenal Glands

ADRENAL GLANDS

mineralocorticoids

Glucocorticoids

Androgens

EpinephrineNorepinephrine

Physiology

• Hypothalamus – Corticotropin realeasing factor (CRF) >>> ____________________________________________________________________(ACTH)

– >>> ADRENAL CORTEX

• _________________ hormone

• __________________ hormone

• ___________________ (Androgens)

• SNS >>> ADRENAL MEDULLA >>> _____________ and ____________________

– Increase HR, Inc. BP, Dilated air passages – lungs, dec. GI function, vasoconstriction

Hormone Functions

Hyperadrenocorticism (Cushings Disease)

• Definition: Disorder caused by deleterious effects of ________________________ circulating cortisol concentrations on multiple organ systems

• Systems affected: Pansystemic disease– Renal– Skin– Cardiovascular– Respiratory– Endocrine/metabolic– Musculoskeletal– Nervous– Reproductive

Cushing’s Disease

Effects of excess glucocorticoids:1. ____________________ inflammation2. ____________________ immune system3. ___________________ cartilage growth, development,

and repairCauses: 1. ___________________________ (pituitary-dependent disease) –

85% of cases2. ____________________________ (excess cortisol secretion

independent of pituitary control) – 15-20% of cases3. Overmedication with glucocorticoids -________________

Cushing’s Disease

Cushing’s Disease

____________________________, pot-belly, pyoderma

Cushing’s Disease

Pot belliedPU/PDMuscle wastingThin coat

Cushing’s Disease

• signs are slow to develop and usually go unnoticed by owner

Clinical Signs:1. Some are similar to hypothyroidism2. Dog >6 yr old (most are female)3. PU/PD/PP4. Pot bellied; obese5. Muscle atrophy and weakness, lethargy, excess panting6. Bilateral symmetric alopecia; pruritis; pyoderma (↓

immune response)7. ___________________ (firm plaques of Ca++ under

skin)8. Abnormal gonadal function (lack of estrus; soft, small

testicles)

Cushing’s Disease: Calcinosis cutis

Commonly seen on the dorsal midline, ventral abdomen and inguinal region. Skin is usually thin and atrophic

Cushing’s Disease: DxChemistry Panel1. ↑ _________, _______________, _________________, _______________2. ↓ BUN3. Lipemia4. ________________ USG < 1.015, proteinuria, hematuria, pyuria, bactiuria

Urine cortisol/creatinine ratios (sample collected at home)1. Normal ratio=no Cushing’s2. Elevated ratio= __________ be Cushing’s

ACTH Stimulation test1. Normal patients show an increase of plasma cortisol2. Pituitary dependent disease (excess ACTH release) and Adrenal tumors: 60-

85% show ____________________________ cortisol response3. Does _______________________ differentiate between Pit disease and

Adrenal tumor

ACTH Stimulation for Hyperadrenocorticism

• Take a pre blood sample.

• Inject ACTH stimulation gel or liquid– Verify amounts with lab as there is

difference between amount to be injected with gel and liquid.

• Wait two hours and take a post sample

Cushing’s Disease: Dx

Low-Dose Dexamethasone Suppression Test1. Inject low dose of steroid (should suppress ant. pit [ACTH])

2. Measure plasma cortisol at 0, 4, 8 h

Interpretation:1. Normal dogs will show ________________ in plasma cortisol

2. Pituitary tumor and adrenal tumor will not show any effect at 8 h (cortisol will still be __________________)

Cushing’s Disease: Dx

High-Dose Dexamethasone Suppression Test (used to ______________________ between Pit Dis and Adrenal tumor)

1. Dosing: 0.1 mg/kg IV

2. Collect plasma cortisol at 0, 4, and 8 h

Interpretation:1. Pituitary dependent disease—70-75% will show

__________________ at 4 or 8 h

2. Adrenal tumor—__________________ change in plasma cortisol level (tumor is autonomous)

Cushing’s Disease

ACTH stimulation:Exaggerated response

High dose dexPit: Decrease 4, 8 hrsAdrenal: No change

Low dose dexNormal: reducePit/Adr tumor: high

Cushing’s Disease: Rx

_____________________ removal—1. Specialized surgery; most vets would refer surgery

2. Pituitary tumors are not surgically removed

Medical treatment

1. Lysodren (o,p,DDD)—necrosis of z fasiculata (middle), z reticularis (deep)

-repeat ACTH stimulation q 7-10 d until cortisol normal

-like chemotherapy

-excess dose affects z glomerulus (_____________________)

Cushing’s Disease: Rx

2. trilostane (Vetoryl®)—less side-effects than o,p,DDD

-interfers with cortisol production (doesn’t kill cells)

-FDA approved

Cushing’s Disease: Client info

• Serious disease; life-long treatment

• Periodic monitoring required

• Addison’s disease may result (_________, _____________, _______________)

• Prognosis: average life expectancy is 20-30 mo on therapy with frequent recurrence of clinical symptoms – varies with cause (pit vs adrenal, tumors)

HARD TIMES“In the depths of winter, I finally

learned that within me there lay an invincible summer.”

-Albert Camus

Addison’s Disease (Hypoadrenocorticism)

• Definition: Disorder caused by _________________ production of glucocorticoids (cortisol) or mineralocorticoids (aldosterone) or both

• Secondary disease caused by chronic administration of _______________________

Addison’s Disease (Hypoadrenocorticism)

• Not as common as Cushing’s Disease; rarely seen in cats

• Deficiency of Glucocorticoids and Mineralocordicoids

• Clinical signs due to Mineralocorticoid (____________________) deficiency

Clinical Signs:1. lethargy, weakness, anorexia, wt loss

2. Vomiting/Diarrhea

3. PU/PD, dehydration

4. _________________________________________

Addison’s Disease

• Pathophysiology– Decreased aldosterone => Increased ____

and decreased _________________– => decreased volume =>_______________,

hypotension, dehydration, weakness, depression

– Hyper K => heart (____________________)– Glucocorticoid deficiency => vomiting,

diarrhea, melena, lethargy, wt loss, hypoglycemia (less common than expected)

Addison’s Disease: Dx

Chem Panel

Na:K ratio <___________________ !!!(normal=27:1 to 40:1)

↑ BUN, Creatinine, Ca++

↓ blood glucose, albumin (less common)

ACTH Stimulation test (________________________ test)

normal dog= ↑ cortisol

hypoadrenocorticism dog= _______________ , unchanged cortisol level

Endogenous ACTH will be increased (1º hypoadrenocorticism; lack of neg feedback)

What is your Dx?

Chem Panel (What is not normal?)

Parameter Value Normal valueBUN 81 mg/dl 7-27 mg/dlCreatinine 2.1 mg/dl 0.4-1.8 mg/dlSodium 131 meq/L 141-156 meq/LPotassium 6.5 meq/L 4.0-5.6 meq/LNa:K ratio 20 27-40

What is your Dx?

ACTH Stimulation Test ResultsValue Normal

Plasma Cortisol

Pre-ACTH 0.2 2-6 Post-ACTH 0.3 6-18

Addison’s Disease: RxAcute Crisis (may be life-threatening situation)1. Normal saline IV (low _____________ is hallmark finding of Addison’s)

2. Glucorticoid replacement(cortisol will also be low)a. Dexamethasone or Prednisone (IV or IM)

3. Mineralocorcorticoid replacementa. ____________________ (fludrocortisone acetate)—po

b. _____________________-V (desoxycorticosterone pivalate) injection

Chronic Management1. Glucocorticoid replacement

a. Prednisone

b. Prenisolone

2. Mineralocorcorticoid replacementa. Florinef® (fludrocortisone acetate)—po daily (not cheap; 50¢/tab)

b. Percortin-V (desoxycorticosterone pivalate)—inj ~monthly (expensive)

3. Monitor electrolytes, BUN/Creatinine, clinical signs

Addison’s disease: Client info

1. Mineralocorticoid deficiency is life-threatening

2. Animal requires periodic blood tests

3. Glucocorticoids needed in times of stress

4. Always remind attending vet of pet’s condition

5. Hormone replacement therapy continued for life of pet

6. Prognosis: Good to excellent after stabilization and treatment