ENDO

Question 1

What helps increase blood calcium

Answer 1

PTH and Vitamin D
Pulls Ca from bone and GIT

Question 2

What protein can cause calcium to be low

Answer 2

Bound to albumin
low albumin = low calcium
(But there may still be some iCa so check) ionised

Question 3

What high electrolyte can cause calcium to be low

Answer 3

Phosphate binds to calcium (complexed fraction)
High phosphate = more bound = low readings

Question 4

Causes of hypercalcaemia in dogs and cats

Answer 4

commonly increased PTH, PTH-like, VD activity, or ostemolyitis
Dogs: malignancy, Hypoadrenocorticism common
cats: idiopathic, renal failure common

Categories:
Parathyroid dependent: neoplasia of the gland or hyperplasia
- see high PTH and high Ca

Parathyroid independent: Malignancy, vitamin D, feline idiopathic, renal failure, osteomyelitis, hypoAC
- see low PTH and high Ca

Question 5

way to remember some hyperCa causes

Answer 5

• H - Hyperparathyroidism
  
  • A - Addison’s
  • R – Renal (total Ca, horses)
  • D - Vitamin D
  • I - Idiopathic
  • O - Osteolysis
  • N - Neoplasia
  • S - Spurious

Question 6

Categories of parathyroid independent causes of HyperCa

Answer 6

Malignancy: Lymphoma, anal sac adenocarcinoma, myeloma, bone caner, parathyroid adenoma

Vitamin D excess: poor diet or supplements, rodenticide

Question 7

How to tell apart PTH mediated and vitamin D mediated hhypercalcamia on bloods

Answer 7

PTH: causes high calcium but low phosphorus (lost at kidneys)

Vitamin D: high calcium and phosphorus (causes both to be absorbed from GIT and bone)

Question 8

What else can be measured in blood to investigate causes of hypercalcaemia (Other than calcium)

Answer 8

PTH and iCA

High iCa and low PTH = independent of parathyroid as gland is behaving as expected (Vit D and malignancy)

Originates from parathyroid gland:
- High iCa and high PTH = parathyroid not supressed appropriately so issue of parathyroid gland origin
- Low iCa and low PTH = Parathyroid not working as it should be secreting PTH to raise calcium, so issue originates from parathyroid gland

Question 9

causes of hypocalcaemia in dogs

Answer 9

primary hypOparathyroidism (Low iCA and low PTH)
- Disease destroying cells or post thyroid surgery in cats

demands exceed supplies
- paripartuient (eclampsia), poor diet, renal issue
- this leads to secondary hyperparathyroidism, as iCa is low so PTH is high

Question 10

types of Hyperadrenocorticism (Cushing’s)

Answer 10

Pituitary deponent = excess ACTH (and cortisol)
Adrenal dependent = excess cortisol
Iatrogenic = exogenous steroids

Question 11

CS of HyperAC (Cushing’s)

Answer 11

PUPD (Cortisol antagonises ADH)
Hepatomegaly
Muscle wastage and weakness (Pot belly)
Polyphagia
DERM: Skin thinning, calcinosis cutis, symmetrical alpopecia

Bloods: high ALP, ALT, bile acids, glucose and low urea, stress leukogram (high N, low Ly)

Question 12

Dx of Cushings (screening)

Answer 12

Screening:
Low dose dexamethasone test
- Normal = negative feedback leads to low cortisol (and low ACTH)
- Failure of cortisol suppression following dexamethasone administration. Pituitary may see slight decrease or flatline, adrenal will remain always high
- Long test (8 hours) and multiple samples (3)

ACTH stimulation test
- Normal = cortisol will rise with ACTH
- Adrenal dependent = exaggerated response as adrenals are larger (tumour or hyperplasia from steroids)

• Urine cortisol:creatinine – high ratio means animal might have HAC

Question 13

Diagnosis of Cushing’s (differentiation)

Answer 13

Differentiation
- Endogenous ACTH
Pituitary = high ACTH
Adrenal = low ACTH through negative feedback

• High dose dexamethasone suppression test
  adrenal = cortisol stays high
• Imaging (Brain and adrenals)
  Pituitary - both enlarged,
  adrenal = one atrophy and one hypertrophy

Question 14

Tx for Cushing’s

Answer 14

Trilostane (synthetic steroid with no hormonal activity= competitive inhibition at adrenals)
lowers glucocorticoid levels
give SID

also Selegiline and Mitotane (not licensed)

Question 15

what does a Phaeochromocytoma screte

Answer 15

catecholamine

Question 16

3 roles of insulin

Answer 16

inhibits ketogenesis
stimulates cell glucose uptake
stimulates cell K+ uptake

Question 17

Two types of diabetes:

Answer 17

T1 Insulin deficiency diabetes: Most common in dogs, occurs when the pancreas is damaged or not functioning properly

T2 Insulin resistant diabetes: More common in older or obese dogs or temporarily in female dogs during heat (Mammary growth hormone drives insulin resistance)

T2 more common in cats but often not due to obesity

Question 18

Signs of diabetes

Answer 18

PUPD (Osmotic diuresis)
Polphagia
Weight loss/ex intolerance/ lethargy
Recurrent infections (especially UTI)
Ketotic breath
Cataracts (omstic effects of glucose => sorbital in lens)

Question 19

Dx for diabetes

Answer 19

Fasting hyperglycaemia
Glucosuria (has to be in combo with hyperglycaemia)

also:
high liver enzymes, cholesterol and TAG, fructosamine

Question 20

Tx for diabetes

Answer 20

Insulin injections
- Caninsulin has immediate action and is BID
- ProZin is BID as it has a longer action

If collapsed: IVFT, soluble insuline

diet and exercise:
- High quality protein with fibre and complex carbohydrates
- Consistent diet
- Regular, small and frequent exercise

Monitor: blood glucose checks to generate blood glucose curves

Question 21

Interpreting glucose curves

Answer 21

Want to see small fluctuations in glucose, remaining within normal values

Outside of normal = dose too low

Very low then very high = SID not enough, change to BID

Question 22

what is a nadir on a glucose curve

Answer 22

Lowest glucose concentration attained (nadir concentration)
Time of nadir represents time of peak effect

Question 23

Seeing a lack of response to what amount of insulin means resistance should be investigated

Answer 23

over 2iu/kg

Question 24

How is fructosamine useful

Answer 24

· Indicates the average BG during the preceding 1-3 weeks
· Often not affected by transient stress hyperglycaemia

Question 25

what is the somogyi effect

Answer 25

Somogyi effect = we induce hyperglycaemia by giving too much insulin

Hypoglycaemia develops initially so the body has an exaggerated response to induced hyper-glycaemia

Question 26

how do some feline diet lead to death of beta cells

Answer 26

inappropriate carbohydrates in diet = glucose toxicity = high BG = glycogen deposition in the pancreas = apoptosis of beta cells = less insulin so hyperglycaemia

Question 27

feline dietary treatment for DM

Answer 27

low carbs high protein (good quality)

Question 28

What leads to diabetic ketoacidosis

Answer 28

Reduced insulin → Reduced glucose uptake into cells → metabolic energy deficit
Ketones produced instead (from glucagon)

Ketones lead to:
- metabolic acidosis
- inappetence, nausea, reduced mentation, vomiting

Question 29

Signalment and presentation of DKA

Answer 29

Middle aged to older, newly diagnosed often
Since diagnosis – PUPD hasn’t resolved, weight loss has continued.
Progressive lethargy, anorexia and vomiting.

dehydrated, hypovolaemic

Question 30

Dx of DKA

Answer 30

BHB ketone in blood
metabolic acidosis on blood gas analysis

Also:
- Electrolytes: Low phosphorus, potassium, sodium, chloride, calcium
- Potassium can sometimes look high due to haemoconcentration (but really is slow due to anorexia, vomting, and PU)

Question 31

Tx of DKA

Answer 31

IVFT (Hartmann’s) to restore volume
Only give insulin once hydration stabilised to create normal glucose levels

Question 32

What is Hyperglycaemic Hyperosmolar Syndrome

Answer 32

Rare (<5%) but important.
Pathogenesis is similar to DKA BUT ketones not elevated
* Hyperglycaemia → glucosuria → osmotic diuresis → haemoconcentration → hyperglycaemia increases → osmotic diuresis ect ect

Get crazy high levels of glucose (over 33) and blood osmolality (measure this to differentiate)