Feline Adrenal

Question 1

A 14 year old DSH presents for PU/PD/PP and occasional vomiting and diarrhea. On exam, the coat quality is poor, the cat is weak, and BCS is 6/9. The liver is palpable. Before drawing blood, what test should you do on this cat?

Answer 1

Blood pressure

*Anything over 200 is sketchy. 250 is where we expect blood draws to raise ICP and cause a brain bleed.

Question 2

Labs on the cat show a lymphopenia, and increased cholesterol, glucose, and ALP. T4 is within normal range. How can we know if the elevated glucose is from stress or diabetes mellitus?

Answer 2

Get a fructosamine level

Question 3

T/F: It is common for a cat with hyperadrenocorticism to also have diabetes mellitus.

Answer 3

TRUE

Question 4

A cat presents PU/PD/PP, BCS 5/9, and lethargic. You note calcinosis cutis bilaterally on the dorsum. LDDS test supresses at both the 4HR and 8HR evaluations. What other laboratory test can you do to try to confirm HAC in this patient?

Answer 4

ACTH stim

*Can also do cortisol:creatinine ration on the urine but it’s not very specific.

*

Question 5

What is the main cause of primary hypoadrenocorticism in cats?

Answer 5

Idiopathic

*occasionally due to neoplasia/trauma

Question 6

Secondary hypoadrenocorticism in cats is frequently iatrogenic, after administration of what drugs?

Answer 6

Corticosteroids

Megestrol acetate

Question 7

A 6 year old MN DSH presents with a history of intermittently not feeling well for awhile. At this time the cat is not eating and is lethargic. He has lost weight over the past couple months and is vomiting more. The owner also states that he has been drinking more and making more trips to the litter box. Despite a history of drinking more water, you find the cat to be 10% dehydrated. Lab results:

Liver enzymes are mildly increased

Decreased Na+ and Ca++

Increased K+

USG: 1.020

What specialty lab test would you like to do next?

Answer 7

ACTH stim

Question 8

You perform an ACTH stim on the 6 year old cat. Baseline cortisol is below reference range. You inject ACTH and wait one hour to take the next sample, which is also below reference range. What does this confirm?

Answer 8

Hypoadrenocorticism

Question 9

ECG on the cat with hypoadrenocorticism. What is the reason for the abnormal waves?

Answer 9

Hyperkalemia

*Absence of P wave, tall, spikey T wave

Question 10

The USG from the cat with hypoadrenocorticism was 1.020. This is too low for a cat who you estimated to be 10% dehydrated. Does this confirm kidney disease as well?

Answer 10

No. Patients with hypoadrenocorticism are losing Na+ in the urine due to lack of mineralocorticoids. Decreased Na+ concentrations mean the animal is unable to concentrate urine due to medullary washout in the kidney.

Question 11

What is the treatment for the cat with hypoadrenocorticism?

Answer 11

Aggressive IVF to replace deficits

Address hyperkalemia

Fludricortisone or DOCP (mineralocorticoids)

Prednisolone (glucocorticoids)

Question 12

What causes Conn’s Syndrome in cats?

Answer 12

Hyperplasia or neoplasia of the adrenal glands

*overproduction of mineralocorticoids (aldosterone)

Question 13

What are the effects of aldosterone on the kidney?

Answer 13

Na+ resorption

K+ excretion

H+ excretion

Question 14

What channels does aldosterone activate in the kidney to reabsorb Na+ and excrete K+?

Answer 14

ENaC

NCC

Na/K-ATPase

Question 15

Overall, aldosterone mediates (vasoconstriction/vasodilation) by upregulating ET, ACE, and production of Angiotension II.

Answer 15

Vasoconstriction

Question 16

A 10 year old DSH presents with a history of not eating and apparent blindness. On opthalmic exam, you discover retinal detachment and ocular hemorrhage. The cat is weak and underweight. Labs show increased Na+ and markedly decreased K+. BP is 210mmHg.

What diagnostics do you need to confirm your diagnosis?

Answer 16

Aldosterone level (high)

Ultrasound of the adrenals (enlarged)

*Conn’s Syndrone. Clinical signs related to hypokalemia and hypertension.

Question 17

What is the MST in cats with Conn’s syndrome if they are treated medically vs surgically?

Answer 17

2-3 years

*MST is the same whether they are treated medically or surgically, have unilateral or bilateral disease, or have adenoma vs adenocarcinoma.

Question 18

What is the treatment for cats with Conn’s syndrome?

Answer 18

Amlodipine

Potassium supplememt

Spironolactone

or surgery