Less common - V/D/Fever/Ventroflexion of neck (thiamine def, hypokalemia), ataxia (mm. weakness)
CBC: Stress leuk Heinz bodies (LSA, DM will have this too)
CHEM: HYPOcholesterolemia Mild/mod inc ALP and/or AST Mild inc ALT (hepatotoxic, ishemia) Hepatic lipidosis (anorexic) in ALP DM or stress
1006-1060, GFR, renal, ADH
PU/PU in hyperthyroidism: Azotemia with a USG from _____ - _____ Increased T4 causes and increase in _____ Increased GFR = hyperfiltration, which may mask _______ disease. Decreased USG due to increased medullary flow Thyroid hormones also will inhibit _____
No, (Serum) Total T4
If a hyperthyroid cat has a USG below 1035, can you say this is renal or prerenal? If not, what other tests should you run?
Free T4 (ED)
Best test for hyper and hypothyroid?
If an animal tests positive for hyperthyroidism using total T4, but you also suspect a concurrent non-thyroid DZ, when should you retest?
T3 (suppression test)
What is a SUPPRESSION test you can use to DX hyperthyroid?
Little to none
If an animal has hyperthyroidism, what effect will a T3 stim have on it?
Owner compliance (check if correctly dosing when doing a T3 suppression stim)
When is the ONLY time you would measure T3?
Plain (red top)
What tube should you collect blood for a T3 suppression stim?
PHARM Q: Drug used to TX hyperthyroidism in CATS?
CRH, ACTH, Cortisol (stress response)
The hypothalamus secretes ______ which causes a release of ______ at the pituitary, which causes secretion of ______ at the adrenal glands.
Is the most common cause of Cushings primary (adrenal cortical adenoma) or secondary (Pituitary dependent HyperA)?
What happens IN THE LIVER when cortisol is high? Deposition of ________ Steroid ________ Induction of enzyme: _______ (DOGS) Increase in ______ ______
catabolism, gluco(neogenesis) and lipolysis
What happens in TISSUES when cortisol is high? Overall tissue _________ via ____neogenesis and ________.
In Cushings animals PU/PD due to inhibition of ______
Low (T4, T3)
What thyroid levels do Cushings patients have? AKA Euthyroid sick syndrome!
Cushings can result in another endocrine disease called _____ due to ______ resistance in CATS (sometimes dogs)
PDA (ADA -> SX)
In DOGS Cushings has to be distinguished b/w PDA and ADA, becuase _____ can be treated medically.
In CATS with Cushings, most cases are treated with ____
Regular Insulin (IV)
PHARM Q: Drug used to TX Insulin dependent Ketotic DM =
NPH Lente Ultralente Protamine zinc
PHARM Q: Drugs (4) used to TX Insulin dependent DM (no ketosis) =
Sulfonylureas (MOA = stimulate Beta cells to secrete insulin)
PHARM Q: Drug used to TX insulin resistant DM =
Mitotane (Ketoconazole can also be used)
PHARM Q: Drug of choice to TX Pituitary Dependent Cushings =
Selective destruction of adrenal cortex
PHARM Q: MOA of Mitotane
PHARM Q: Drug used to TX PPID in HORSES =
Binds and stimulates DOPAMINE receptors in pars intermedia
PHARM Q: MOA of Pergolide mesylate
2 common signs of PPID in HORSES:
C/S: CYSTITIS AND RECURRENT UTI HYPERTENSION -Truncal obesity/alopecia, Pot Belly, abdominal distention -Polyphagia -PU/PD (ADH suppression) -Muscle weakness (abd. distension)/wasting -Thin skin (opposite hypoT4) -Comedomes -Pyoderma (immunosuppression and thin skin) -Polypenia (weak resp muscles) -Neuro signs (PDA) -Pulmonary thromboembolism
Emphysematous cystitis (E. Coli proliferate and produce gas bubbles in wall)
PATH II Q: What is commonly seen with DM patents in the u. bladder?
What reproductive changes could you see in Cushings patients? ______ due to gonadotropin suppression (females) ______ atrophy (males)
CATS (But, severe thinning of skin - wounds by grooming)
What species with Cushings may not show any signs at all?
CBC: (Dogs) POLYCYTHEMIA STRESS LEUKOGRAM Left shift if pyoderma Inc PCV, nRBC without regeneration
CHEM: INCREASED ALP (5-45x normal) HYPERglycemia (CATS - IRDM) UTI without PYURIA (immunosuppressed) LOW Urea (PU/PD) USG - Hyposthenuric, Isosthenuric (ADH suppression)
Dexamethasone (.1% cortisol)
What is the steroid of choice to test for Cushings?
Cushings (DM increased)
Using a serum fructosamine test, which will have a normal level of fructosamine, Cushings or DM?
How long should you GRADUALLY wean an animal off of cortisol based drugs before testing for Cushings?
Urinary cortisol:creatinine ratio (UCCR) ACTH stim
Name 2 SCREENING tests for Cushings (Can't use to confirm Cushings)
What will stress, PU/PD and Cushings do to a UCCR?
Which UCCR will be very high, stress, PU/PD and Cushings?
High (high true positives), low (lots of false + --> a lot of things can look like Cushings)
UCCR has a ____ sensitivity, but _____ specificity.
How do you avoid stress when taking a UCCR? Sample urine in the _____ (time of day) 2 days after the vet visit
A low/normal UCCR will rule in or out Cushings?
The UCCR can rule in DM, DI, Pyometra, hypercalcemia, renal/liver failure by showing an ________ (increase or decrease).
ACTH stim LDDS (Low dose dex suppression)
What 2 adjunctive tests asses the hypothalamic-pituitary-adrenal gland axis?
If results in dogs are not definitive of Cushings, you can do UCCR over ___ consecutive days
What is the ONLY SCREENING TEST that can be used to (DX) 1. Iatrogenic Cushings 2. Addison's 3. Treatment assesment using Mitotane / Trilosane
Which test is more sensitive, ACTH or LLDS?
maximally, adrenal, cortisol
The goal of a ACTH stim is to ________ stimulate the _______ cortex to make as much ________ as possible
ACTH stim will not 100% diagnose an animal with PDA (84%), ADA (51%) or iatrogenic CUSHINGS (14%). This is b/c it has a lower ________ than LDDS.
Drugs such as __________ and glucocorticoids can elevate the post ACTH value and well as increase liver enzymes (ALP).
ACTH (Pituitary neg. feedback)
What will a LDDS suppress?
Normal animals will ____ the amount of cortisol produced when given Dex
CUSHINGS patients (All ADA and most PDA) are resistant to negative feedback of Dex, so ______ levels remain high when you give Dex.
Illness Chronic Stress
What, besides Cushings, can also override the negative feedback of Dex?
If the LDDS is more sensitive than ACTH stim, it will have less ____ _____
If an animal responds by a decrease in cortisol 4 hours hours after given Dex this could mean they're healthy or have ______
There is a high false positive rate when using LDDS because lots of things like stress won't allow the animal to suppress (keep cortisol low). This means LDDS has a low _________
You can say it's probably Cushings when the __hr value is above the cutoff.
1.45, 50 baseline 50% baseline
What are the 3 critiera used to help distinguish between PDA from ADA? 1. 4hr plasma cortisol <____microg/dl 2. 4hr plasma cortisol <______%of _______ 3. 8hr plasma cortisol >______ or 1.45
No (Only 60-65% will - Some won't even suppress AT ALL)
Will ALL PDA suppress below 1.45mircog/dl at 4 hours?
No suppression (at 4 or 8hr)
What is expected of ADA Cushings using the LDDS?
Oral-LDDS (test urine instead of plasma)
If IV-LDDS and UCCR inconclusive, what other method could you use?
HDDS (10x Dex dose)
After a DX of Cushings has been made with ACTH or LDDS, how else can you confirm a PDA or ADA? What discriminatory test can you use?
What is a more sensitive diagnostic test you can utilize to DX ADA?
If Cushings, how would you know it's an adrenal carcinoma aka ADA? ______ enlargment.
If Cushings, how would you know it's a pituitary adenoma aka PDA/ _____ enlargement.
Using a HDDS test, if you have suppression at 4hr and 8hr, what can you definitively diagnose?
NEITHER!!!! (15% of PDA won't suppress at all)
Using a HDDS test, if you don't have any suppression at all at 4hr and 8 hr, which form can you DEFINITIVELY diagnose?
What is another, relatively not available unfortunately, test to distinguish between PDA and ADA?
High (It's an ACTH secreting tumor!)
Using endogenous ACTH, what will the levels of ACTH be if PDA?
Low (Suppresses pituitary)
Using endogenous ACTH, what will the levels of ACTH be if ADA?
Plastic EDTA tube (spin down and freeze plasma ASAP)
What tube should you use to collect blood for an endogenous ACTH assay?
Occult HyperA - "Alopecia X" Syndrome diagnosed with a _____ ___ test to measure sex hormones and aldosterone
19hr dex suppression test
What test can be used to DX PPID in a HORSE?
What is the most common cause of Addisons, primary (detroyed adrenals) or secondary (pituitary deficiency of ACTH)?
What drug can cause Addisons?
Trichuris vulpis (whip worm)
What parasite mimic's Addisons on a CBC/Chem profile?
HYPO Na, Cl HYPER K
What are the main (3) electrolyte imbalances with Addisons?
Secondary (ACTH does not affect Aldosterone!)
Which form of Addison's DOES NOT have electrolyte imbalance?
C/S: Episodic frequency of dec mineralocorticoid signs = -Weight loss -Weak pulse and BRADYCARDIA (High K) -DEPRESSION & WEAKNESS -DECREASED GLUCOCORTICOID -Dehydration or HYPOTENSION -PU/PD due to ELECTROLYTE imbalances -V/D -Shivering, shaking, shock. collapse -Hyperpigmentation -Stress intolerance
FALSE! (Hypo Na,Cl - med washout)
T/F: PU/PD in Addisonians is due to an inhibition in ADH?
CBC: -Hemoconcentration -Mild, non-regenerative anemia (~MASKED) -High Lymphocytes and Eosinophils =REVERSE STRESS LEUKOGRAM, even when very sick
CHEM: -HYPER K, Phos, HYPER Ca (n = iCa) -HYPO Na, Cl -Metabolic acidosis (Dec HCO3) *Na:K <15* -Dehydration CAN MASK electrolyte LOWs -Hypovolemia dec GFR -Dec GFR -> PRERENAL AZOTEMIA -Gastric hemorrhage increases UREA -USG <1.025; med washout
What is the Na:K likely to be in: Addisons Uroabdomen CRF GI DZ (Whips, Salmonella) Chylothorax Severe metabolic acidosis CHF Breeds: Shiba inu, Shar Pei Young horses Clotting process releases K (Lots of platelets)
Basal cortisol ACTH stim Endogenous ACTH
3 Tests used for Addisons:
What is the only endocrine test that you only have to take a blood sample for once to make a diagnosis?
What is the gold standard test for Addisons?
What is diagnostic for Addisons using a ACTH stim? Failure of cortisol to _______ from baseline or increase >___microg/dl
No, Endogenous ACTH
Does an ACTH stim DX between primary or secondary Addisons? If not, what can?
HIGH (Pituitary senses low electrolytes and is trying to tell the adrenals to make glucocorticoids! Also, there is no negative feedback coming from the adrenals)
Primary Addisons will have _____ ACTH using an endogenous assay.