Feline Endocrinopathies

Question 1

You are presented with a diabetic cat that is showing signs of insulin resistance, which endocrine diseases are more likely to cause insulin resistance in a diabetic cat?

Answer 1

(Hyperadrenocorticism and acromegaly; also hyperthyroidism but not as commonly as the other two)

Question 2

What are some of the more common clinical signs and PE findings associated with hyperadrenocorticism in cats?

Answer 2

(PU/PD, abdominal enlargement, polyphagia, skin atrophy; also but less commonly muscle wasting, weight loss, alopecia, skin fragility, unkempt haircoat, plantigrade stance, hepatomegaly, and weight gain)

Question 3

(T/F) It is very common, 80% of cases, for hyperadrenocortic cats to also have diabetes mellitus.

Answer 3

(T)

Question 4

Why do cats not have severe increases in ALP when they have hyperadrenocorticism like dogs do?

Answer 4

(Because cats do not have the cortisol isoenzyme that increase ALP in dogs, so ALP elevation is less common in cats with hyperadrenocorticism when compared to dogs)

Question 5

What laboratory (blood work, UA) findings do you expect to find in a cat with hyperadrenocorticism?

Answer 5

(Diabetes mellitus/hyperglycemia, hypercholesterolemia, increased ALT and +/- ALP, glucosuria, proteinuria, and minimally concentrated USG)

Question 6

Which Cushing’s test would you reach for in a cat you suspect has hyperadrenocorticism based on clinical findings?

Answer 6

(LDDST, ACTH stim has poor sensitivity in cats)

Question 7

What organ has to be abnormal to cause feline acromegaly?

Answer 7

(The pituitary gland, either tumor or pituitary overgrowth leading to excess release of growth hormone)

Question 8

How does feline acromegaly cause the following possible presentations:

• Stridor
• Heart failure
• Neurological signs

Answer 8

• Stridor (From narrowing of nasal cavities d/t facial bone growth d/t excess growth hormone)
• Heart failure (From heart enlargement d/t excess growth hormone)
• Neurological signs (From tumor growth)

Question 9

Is weight gain or weight loss more common in a case of acromegaly in cats?

Answer 9

(Weight gain)

Question 10

What might you find during a physical exam of a cat with acromegaly?

Answer 10

(Abdominal organomegaly, broad facial features, clubbed paws, prognathia inferior, widening interdental spaces, enlarged tongue, and heart murmur)

Question 11

What can you test for in a cat’s blood to indicate they have acromegaly?

Answer 11

(IGF-1 levels, otherwise need CT/MRI to diagnose an enlarged pituitary)

Question 12

What are the two preferred treatment options for feline acromegaly?

Answer 12

(Hypophysectomy or radiation therapy; medical therapy is not as effective as the other two options)

Question 13

What are the two drug options for treatment of feline acromegaly and what do those drugs do?

Answer 13

(Pasireotide → somatostatin analog (has negative feedback on GH excretion); cabergoline → dopamine receptor agonist (has negative feedback on the pituitary in general))

Question 14

What can occur with the common simultaneous diabetes mellitus in cases of acromegaly where you choose to not treat?

Answer 14

(It will become hard to control, you’ll need to use high doses of insulin, and there is a possibility of sudden hypoglycemia)

Question 15

Why do cats with hyperaldosteronism have signs such as cervical ventroflexion, weakness/collapse, dysphagia, and ataxia?

Answer 15

(Bc they are hypokalemic)

Question 16

Why are cats with hyperaldosteronism hypertensive?

Answer 16

(Bc they are retaining sodium and water)

Question 17

What other disease does hyperaldosteronism look a lot like (which has caused it to go underdiagnosed)?

Answer 17

(Looks a lot like CKD (hypokalemia, azotemia, increased CK), if you are treating a cat for CKD and they are not responding, consider testing for hyperaldosteronism)

Question 18

How do you diagnose hyperaldosteronism?

Answer 18

(Test plasma aldosterone concentration and/or perform US and look for an adrenal tumor or bilateral enlargement of the adrenals)

Question 19

What is the preferred treatment for primary hyperaldosteronism in cats?

Answer 19

(Unilateral adrenalectomy, can use spironolactone as an aldosterone antagonist, amlodipine, and potassium supplementation for medical)

Question 20

What are differentials for secondary hypertension?

Answer 20

(Renal disease (look for azotemia), hyperthyroidism (test T4), hyperaldosteronism (test aldosterone), and pheochromocytomas (rare))