29. Diseases of the adrenal glands in dogs and cats Flashcards
Addison’s Disease
Decreased adrenal gland hormones
rare but life threatening
Predisposed to Addison’s Disease
Young / middle aged animals
Bitches
great dane, rottweiler, poodle, schnauzer, westie
Primary Addison’s Disease
if 90% of adrenal cortex tissue is lost
decreased cortisol & aldosterone
Increased ACTH
Cause of primary Addison’s Disease
autoimmune destruction of AC
bilateral adrenal tumour
amyloidosis
infection
iatrogenic treatment of cushing’s
Secondary Addison’s Disease
decreased cortisol
normal aldosterone
decreased ACTH
causes of Secondary Addison’s Disease
long term gcc therapy with abrupt stop
hypophyseal tumour
pituitary tumour
trauma
inflammation
gcc/ cortisol deficiency
decreased; GNG, GGL, energy metabolism, fat metabolism, water excretion, mentation & stress tolerance
Aldosterone deficiency
loss of Na, Cl, H20
Retention of K+
hypovolaemic shock
Hypovolaemic shock signs
Decreased; cardiac conduction, output
Decreased; BP, renal perfusion
muscle weakness
nausea
Clinical signs of Addison’s Disease
vomit
diarrhoea
weakness
PU/PD
anorexia
lethargy
dehydration
abdo pain
weight loss
tremor
hypothermia
depression
shock
bradycardia
increased crt
Lab d of Addison’s Disease
Mild normocytic normochromic anaemia
eosinophilia
lymphocytosis
Decreased Na, Cl, cholesterol
Increased - Ca, K
Diagnosis of Addison’s Disease
ACTH stimulation test
ECG
XRAY
Abdo US
ACTH Stimulation test in case of Addison’s Disease
Give 5ug/kg IV tetracosactite
take blood sample at 0 and 1 hr
ECG of Addison’s Disease
Spiked T wave
Increased QT distance
Wider QRS complex
Decreased P wave
Increased PR distance
Bradycardia
Treatment of Addison’s Disease
Correct any perfusion and dehydration deficits
Correct any electrolyte and acid base imbalance
Steroid supplement - hydrocortisone then dex
Mineralocorticoid supplement
Maintenance therapy of Addison’s Disease
Fludrocortisone / DOCP
Prednisolone
NaCl mixed with food
Cushing’s disease of a dog
Increased cortisol
Predisposed to Cushing’s disease of a dog
middle/ old aged dogs
poodle
dachshund
yorkie
vizsla
boxer
Pituitary dependent cushing’s
increased cortisol
increased ACTH
excess acth secretion –> bilateral AC hyperplasia
due to ; hypophysis hyperplasia, adenoma
smaller dogs
Adrenocortical tumours
larger dogs
increased cortisol
decreased ACTH
independent from acth secretion
contralateral adrenal hyperplasia
due to ; adenoma, carcinoma
iatrogenic form of cushing’s disease
long lasting gcc therapy
decreased cortisol
decreased acth
due to ac atophy
Clinical signs of Cushing’s disease of a dog
Polyphagia
PU/PD
Centripetal obesity
Hepatomegaly
Abdominal enlargement
Thin skin
muscle wasting
Atrophied skin
Secondary infections
Alopecia
Hyperpigmentation
Panting
Calcinosis cutis
Anoestrous
Testicular atrophy
Keratin plugs
Lab D of Cushing’s disease of a dog
Increased; proteolysis, GNG, lipogenesis, ALP, cholesterol, lipaemia, blood glucose
decreased ; USG
leucocytosis
neutrophilia
Diagnosis of Cushing’s disease of a dog
Low dose dexamethasone suppression test
ACTH stimulation test
Low dose dexamethasone suppression test
0.01mg/ kg IV dexamethasone
take blood at 0, 4, 8hrs
Treatment of Cushing’s in dogs
Mitotane
Trilostane
Hypophysectomy
Adrenalectomy
Average lifespan of Cushing’s in dogs
2 yrs
Predisposed of Cushing’s disease of cats
Middle/ old aged cats
Clinical signs of Cushing’s disease of cats
Alopecia
Hyperpigmentation
DM
Keratin plugs
fragile skin
Treatment of Cushing’s disease of cats
Mitotane is ineffective
give- trilostane,
hypophysectomy
bilateral adrenalectomy
