Feline Hyperadrenocorticism Flashcards

1
Q

What’s the prognosis of feline HAC compared to the dog?

A

worse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What’s the most common form of feline HAC?

A

85% = PDH, the remainder = ADH (adrenal dependent hyperadrenocorticism)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are some common dermatological changes with feline HAC?

A
  • skin hyperfragility – watch for tears!
  • skin infections (bacterial, fungal)
  • symmetrical, truncal & abdominal alopecia, non pruritic
  • Calcinosis cutis = NOT a thing in cats
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are some metabolic changes noted in feline HAC?

A
  • PU/PD/PP: due to glucocorticoid diabetogenic effects
  • concomitant CKD (not a thing in dogs)
  • if not diabetic or have CKD, then NO PU/PD
  • can have weight loss (minor) or weight gain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are some PE changes for feline HAC?

A
  • poor haircoat
  • pendulous abdomen
  • generalized muscle wasting
  • weight gain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are some concurrent illness that cats with HAC can also have?

A
  1. diabetes mellitus. Typically insulin resistant
  2. frequent, resistant/ hard to resolve infections - a combination of immunosuppression, skin fragility, and concurrent illness
  3. CKD - no causation between CKD and HAC. Cats with USG < 1.020 likely have concurrent CKD
  4. Pancreatitis
  5. Hypertension
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the most common blood work abnormalities noted for feline HAC?

A

about 80% = hyperglycemic, even those that don’t have overt diabetes mellitus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What biochemistry changes are noted with feline HAC?

A
  • hyperglycemia
  • hypercholesterolemia (poor controlled diabetes and increased lipolysis)
  • increased BUN (>50%)
  • increased BUN and creatinine (>25%)
  • cats don’t get steroid induced ALP, so only a mild increase in noted (likely from diabetes, such for ALT increase)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are some CBC changes noted with cats with HAC?

A

Occur in consistently
- lymphopenia
- neutrophilia
- eosinophilia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Is USG > 1.020 possible for feline HAC?

A

yes, the non-diabetic ones can still concentrate urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Overall how does the blood work abnormalities for cat differ from the dog with HAC?

A
  • cat bloodwork = less profound vs the dog
  • but, cat’s PE is more dramatic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What’s the utility of abdominal x-rays for cats with HAC?

A

always need to correlate imaging findings with c/s as presence of mass does NOT equal function’
- increased abdominal enhances abdominal imaging
- but only a small number of cats have visible adrenal mass
- survey rads (chest and abdomen) can help to identify concurrent illness, which may influence treatment/ prognosis
- adrenal mineralization can be an incidental old-age finding in cats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What’s the utility of AUS for cats with HAC?

A
  • experienced ultrasonographer can identify the adrenal glands in healthy cats
  • challenge in differentiating between hyperplastic vs normal
  • malignant ones tend to have vascular invasion
  • if an adrenal mass is noted, should check the liver and spleen for metastasis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What’s the utility of CT/MRI for cats with HAC?

A
  • useful in the diagnosis of adrenal hyperplasia, adrenal tumour, and pituitary tumour
  • can assess for vascular invasion, which can help with adrenalectomy planning
  • correlation of pituitary tumour size and presence of neurological signs is not clear
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Is basal cortisol test effective for feline HAC?

A

No, basal cortisol value is not useful for assessment of adrenal function in cats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What’s the diagnostic value of ACTH stim test for cats with HAC?

A
  • sensitivity = 56-80%
  • DDX = feline hyperthyroidism (for increased post ACTH stim cortisol)
  • cats tend to have less dramatic response compared to the dog
  • peak timing and magnitude is variable
  • typically test 60 & 90min post ACTH
17
Q

What’s the diagnostic value of dexamethasone suppression test for cats with HAC?

A
  • the “low dose” for cat = “high dose” for dogs
  • it’s a good initial screening tool to rule in HAC
  • could possibly aid in ADH vs PDH (PDH will suppress at 8h)
  • if the cat suppresses with low dose but has clinical signs consistent with HAC, can try a “dog low dose” (0.01mg/kg vs 0.1mg/kg)
18
Q

What’s the diagnostic value of UCCR for cats with HAC?

A
  • it’s a good screening (sensitivity) but has poor specificity (ex. feline hyperthyroidism also can have increased UCCR)
19
Q

What’s the treatment for ADH in cats?

A

Adrenalectomy
- will need imaging to assess for possible invasion into major blood vessels or kidneys
- post-op hypoadrenocorticism = common
- will need fludrocortisone supplementation long term; prednisolone can usually be tapered overtime
- will help with glycemic control/ insulin dose

20
Q

What are the surgical options for PDH in cats?

A
  • trans-sphenoidal hypophysectomy & bilateral adrenalectomy
  • will require lifelong supplementation (fludrocortisone and prednisolone) and treatment for diabetes insipidus
21
Q

What’s the utility of trilostane for cats with HAC?

A

Trilostane = competitive inhibition of 3-beta hydroxysteroid dehydrogenase
- can be effective, though no PK studies done
- manufacturer does NOT recommend its use in patients with hepatic or renal compromise
- side effects: lethargy, anorexia, hyponatremia, hyperkalemia
- no published data on monitoring
- initially though ACTH stim, but it is unreliable
- best to base on history and PE findings

22
Q

What are some other medical therapy options for feline HAC?

A

Mitotane
- well tolerated by cats
- however, frequently ineffective at controlling c/s

Metyrapone
- inhibits 11 beta-hydroxylase, used in conversion to cortisol
- it’s at least transiently effective

Ketoconazole
- ineffective in cats
- can inhibit steroid production in dogs and people

23
Q

What’s the role of radiation therapy in PDH cats?

A
  • can resolve neurological and (some) endocrine signs
  • improve glycemic control in acromegaly, unsure about HAC
24
Q

What’s the prognosis of feline hyperadrenocorticism?

A

poor if untreated or unresponsive to treatment
- die of severe infection, or uncontrollable diabetes mellitus

With appropriate treatment, can have good to excellent outcome.