Exam 1- Endocrine and Neuro

Question 1

What is the etiology of primary hypothyroidism?

Answer 1

Immune mediated destruction of thyroid cells—> aka Lymphocytic thyroiditis

Question 2

What are the iatrogenic causes of hypothyroidism?

Answer 2

I-131 Tx
Antithyroid drugs
Thyroidectomy

Question 3

What is euthyroid sick syndrome?

Answer 3

Syndrome where patient has non-thyroid disorder/illness which can cause abnormal thyroid function test results (will have lowered T3 level (most common) and T4 level (if severe and prolonged disease))

Question 4

Which drugs can cause hypothyroidism?

Answer 4

Sulfonamides

Phenobarbital

Question 5

What is the signalment for hypothyroidism?

Answer 5

Middle age to older

Medium to Large breed dogs

Question 6

What clinical signs will you see with hypothyroidism?

Answer 6

Weight gain
Lethargy
Bilateral truncal alopecia
Rat Tail
Seborrhea
Hyperpigmentation
Myxedema/Myxedema coma

Question 7

What CBC and Chem changes would you see with a hypothyroid dog?

Answer 7

Mild non-regenerative anemia
Hypercholesterolemia
Hypertriglyceridemia

Question 8

True or false:

Does a normal T4 level rule out hypothyroidism?

Answer 8

True

Question 9

What will the thyroid hormone and TSH levels look like in a hypothyroid dog?

Answer 9

Decreased T4, decreased fT4, increased TSH

Question 10

Name of t he drug used to treat hypothyroidism

Answer 10

Levothyroxine

Question 11

When should blood levels be drawn to evaluate if the therapy is working?

Answer 11

4-6 hours after 1st pill
Then 1 month later
**If on BID treatment

Question 12

What disease is caused by the excessive production of T3 and T4 (thyroid hormones) due to a functional tumor?

Answer 12

Hyperthyroidism

Question 13

What is the signalment of hyperthyroidism?

Answer 13

Older cat (mean age of 12 years old)

Question 14

List the clinical signs of hyperthyroidism.

Answer 14

Weight loss
Unkempt/scraggly coat
PU/PD
GI signs: Vomting and Di

Hyperactive, tachycardic, vocalization, grumpy, ravenous appetite

Question 15

What is apathetic hyperthyroidism?

Answer 15

Subset of hyperthyroid cats

-Lethargic, poor appetite, weight loss

Question 16

What are th physical exam findings with hyperthyroidism?

Answer 16

Goiter, palpable thyroid slip

Tachycardia, murmur/gallop

Question 17

What are the CBC/Chem/UA changes in a hyperthyroid cat?

Answer 17

Stress leukogram
Increased ALT
Increased ALP (rare)
Variable BUN, Crea, P
Isosthenuria or hyposthenuria (low USG)

Question 18

What is the test to perform in order to get a definitive diagnosis for hyperthyroidism?

Answer 18

T4 level

Question 19

What will the levels look like in a hyperthyroid cat?

Answer 19

Increased T4, increased fT4, decreased TSH

Question 20

What are the non-reversible and reversible treatment options for hyperthyroidism?

Answer 20

Non reversible: Surgery, I-131

Reversible: Methimazole, Diet

Question 21

What is the MOA for methimazole?

Answer 21

Inhibits the synthesis of thyroid hormone by blocking the incorporation of iodine

Question 22

Why would you do a 30 day trial of methimazole before pursuing surgery in a hyperthyroid cat?

Answer 22

To see if azotemia is unmasked/to see if the cat will go into renal failure if the hyperthyroidism is corrected

Question 23

What is the cause of pituitary dependent HAC?

Answer 23

Functional ACTH secreting pituitary tumor

Question 24

True or false:

Adrenal dependent HAC results in bilateral adrenocortical hyperplasia.

Answer 24

False- Pituitary dependent HAC causes bilateral adrenocortical hyperplasia

Question 25

How will the adrenals appear if there is an adrenal tumor present?

Answer 25

One normal/larger gland with contralateral gland atrophy

Question 26

Which form of HAC causes bilateral adrenal gland atrophy??

Answer 26

Iatrogenic HAC, due to the excessive/prolonged use of glucocorticoids

Question 27

What is the signalment for HAC?

Answer 27

Middle age to older age Avg age of 12 years old Seen in Poodles, Dachshunds, Schnauzers, GSDs

Question 28

What are the 5 Ps of HAC?

Answer 28

Panting Potbelly PU/PD Polyphagia

Question 29

What are clinical signs you will see with a HAC patient?

Answer 29

``` Bilateral symmetrical alopecia Muscle/ligament weakness Calcinosis cutis Hyperpigmentation Resp signs: dyspnea CNS: seizures, circling, ataxia ```

Question 30

What CBC/Chem/UA changes will you see with HAC?

Answer 30

``` Stress leukogram Increased ALP Hypercholesterolemia Mild hyperglycemia Mildly increased ALT Low USG- isosthenuria, hyposthenuria ```

Question 31

True or false: | A. Positive UCCR (urine creatinine-cortisol ratio) means that the dog 100% has HAC.

Answer 31

False- Performing a UCCR screens for HAC and a positive result makes HAC more of a possibility (It is NOT diagnostic)

Question 32

What response do you want to see with a LDDST?

Answer 32

1. 50% suppression at 8h sample =PDH 2. 4h sample is less than 1 mg/dL= PDH 3. 4h sample is 50% of baseline sample= PDH

Question 33

True or false: | An exaggerated response (huge increase) on a ACTH stim test means that your patient has HAC.

Answer 33

TRUE

Question 34

What result will you see on a ACTH stim test if the dog has iatrogenic HAC?

Answer 34

Diminished/suppressed response to the ACTH due to gland atrophy (can’t respond)