Endocrine

Question 1

diabetes mellitus

Answer 1

dog - type 1 - not producing insulin

cat - type 2 - not responding to insulin (reversible)

signs -
PUPD
weight loss
recurring infections - skin and urinary
cloudy eyes - dogs (diabetic retinopathy –> glaucoma)

Question 2

hyperadrenocorticism (cushings)

Answer 2

Adrenal or pituitary dependant
overproduction of cortisol from adrenals

increased ACTH –> increased Cortisol –> decreased ADH (decreased ability to concentrate urine)

signs -
PUPD
Pot belly
muscle weakness - affects respiration
hypercoagubility - thromboembolism peri-operative)
hair loss, poor coat condition

Question 3

hypoadrenocorticism (addisons)

Answer 3

underproduction of cortisol and aldosterone
from damage to adrenal glands - neoplasia, granulomatous disease, infarction or iatrogenic
varied signs

reverse stress leukogram

Question 4

paraneoplastic syndromes

Answer 4

clinical signs caused by tumour distant to the tumour or its metastases

anal sac carcinoma - hypercalcemia
sertoli cell tumour - hyperoestrogenism
pituitary tumours -
- rat - prolactin secretion affected –> mammary neoplasia
- cat - growth hormone affected –> acromegaly, myocardial hypertrophy, diabetes
- dog –> downstream cushings
- horse –> PPID

Question 5

hypothyroidism

Answer 5

Immune mediated thyroid destruction

hair loss and oedematous skin

Question 6

hyperthyroidism

Answer 6

overproduction of thyroid hormones –> increased metabolism –> weight loss in cats

Question 7

pheochromocytomas

Answer 7

adrenal medulla tumour
overproduction of catecholamines –> increased blood pressure
anaesthetic risk (CV effects of catecholamines)

tumour can invade caudal vena cava - life threatening

Question 8

PPID

Answer 8

overproduction of cortisol from pituitary dependant - hperplasia/hypertrophy of pars intermedia
hyperadrenocorticism
antigonises insulin production

pathophysiology -
increased gluconeogenesis
decreased glucose utlisation
increased glucose deposition in liver
decreased protein synthesis in muscles
increased fat breakdown and deposition
decreased production and function of WBCs
decreased cell division

signs -
lethargy/poor performance
coat abnormailities
skeletal muscle abnormalities
rounded abdomen
PUPD
regional adiposity/weight gain
laminitis
susceptibility to secondary infections

diagnosis -
basal ACTH assay
TRH- stimulation test

management -
weight loss
minimise post-prandial insulin surges

Question 9

Pituitary hyperplasia and neoplasia

Answer 9

hyperplasia - proliferation of normal cells. no evidence of capsule formation, so significant compression of adjacent tissues

adenoma - compression of surrounding parenchyma, cells have more cytoplasm, psuedocapsule formation, pale or slightly basophilic cytoplasm

carcinoma - needs evidence of metastasis for diagnosis

diagnosis -
gordon and sweets reticulin stain - differentiate between hyperplasia and adenoma - loss of tissue structure in adenoma

different downstream effects by species - see paraneoplastic slide

Question 10

EMS

Answer 10

endocrine or metabolic abnormalities -
insulin dysregulation
regional adiposity
hypertriglyceridemia
seasonal hypertension
systemic inflammation

signs -
laminitis - from insulin dysregulation
obesity and resistance to weight loss
poor performance/lethargy
swelling around groin

diagnosis -
baseline insulin (fasting)
post-prandial insulin - 2 hours after insulin administration