Endocrine

Question 1

How would you diagnose Diabeties Insipidus?

Answer 1

• CBC/Biochem = Normal
• USG = Low <1.005
• Confirm diagnosis with water depravation test once all other PU/PD causes have been ruled out

Question 2

What are some clinical signs/features of Diabeties Insipidus?

Answer 2

• Any age/breed/sex
• Marked PU/PD with nocturia
  
  • Seeking water in strange places
  • Water in preference of food
  • Vomiting after rapid water intake
• Marked signs of water depravation
  
  • Hypertonic dehydration
  • Anorexia, Weakness
  • Disorentiation, ataxia, seizures

Question 3

What tests can you run to investigate adrenal function?

Answer 3

• ACTH stimulation test
• Low Dose Dexamethasone suppression test (LDDST)

Question 4

Diabetes insipidus is rare in dogs and cats - What are the 2 causes of it?

Answer 4

• Central Di - Defective secretion / synthesis of vasopressin(ADH)
• Nephrogenic Diabetes insipidus - primary inability of the renal tubule to respond to vasopressin

Question 5

When investigating PU/PD after running your routine tests what do you do next and how?

Answer 5

1. Investigate

• Eliminate Hepatic Disease
  
  • Pre and Post prandial bile acids
  • Plasma Ammonia
• Investigate adrenal function
  
  • ACTH Stimulation
  • Low Dose Dexamethasone Test
• Perform diagnostic Imaging
  
  • Pyelonephritis, renal failure, hyperadrenocorticism, pyometra
  • Liver disease

2. Remaining Possibilities are :-

• Central Di
• Primary Polydipsia
• Primary Nephrogenic Diabeties Insipidus

Question 6

What tests would you run to routinely screen for PU/PD?

Answer 6

• Urinalysis
• CBC (Haematology)
• Serum BioChem
• Electrolytes
• Total T4 (Hyperthyroidism is very common in cats)

Question 7

What is the normal intake of water for a dog?

What is the normal Urine output for a dog?

Answer 7

• Water intake = 50 - 60mL/kg/day
• Urine output = 20-40mL/kg/day

Question 8

How do you do a water deprivation test on a dog?

Answer 8

• Test USG
• Withhold water
• Retest USG, if normal the Urine should become concentrated

Question 9

What is the normal USG range for Dogs and Cats?

Answer 9

• Dogs
  
  • 1.015-1.045,
  • >1.030 = Normal
• Cats
  
  • 1.35-1.060,
  • >1.035 = Normal

Question 10

What lever of input/output do we class as

Polyuria

Polydipsia

for cats and dogs

Answer 10

• Polyuria
  
  • Urine output = >50mL/kg/Day
• Polydipsia water intake
  
  • Dog = >100mL/kg/day
  • Cat = >45mL/kg/day

Question 11

Name the common causes of PU/PD in Cats

Answer 11

• Chronic Renal Failure
• Diabeties Mellitus
• Hyperthyroidism
• Hypercalceamia
• Pyelonephritis
• HypoKalaemia
• Argomegaly
• Hyperadrenocorticism (Cushings)
• Hypoadrenocorticism
• Diabeties Insipidus

Question 12

Name the common causes of PU/PD in Dogs

Answer 12

• Hyperadrenocorticism (Cushings)
• Diabeties Mellitus
• Chronic Renal Failure
• Pyelonephritis
• Pyometrra
• Hypercalcaemia
• Liver Disease
• Hypoadrenocorticism
• Diabeties Insipidus
• Psychogenic polydipsia

Question 13

What are some reasons for

Central Diabeties Insipidus

Nephrogenic Diabeties Insipidus

Answer 13

• Primary Central Diabeties Insipidus
  
  • Idiopathic
  • Congenital
• Secondary Central Di
  
  • Head Trauma
  • Neoplasia
    
    • Craniopharyngioma
    • Chromophobe adenoma/adenocarcinoma
    • Metastatic neoplasia
• Primary Nephrogenic Diabeties Insipidus
  
  • Congenital V2 receptor defect: Rare (Born with a defect int he receptors in the renal tubials)

Question 14

What is the reference range for Hyposthenuria?

Answer 14

USG<1.007

Question 15

What is the reference range for Isosthenuria?

Answer 15

1.08-1.012