Approach to Polyuria/Polydipsia

Question 1

What is the specific gravity of urine relative to plasma if Hyposthenuria

Answer 1

1.000 to 1.008

Question 2

What is the specific gravity of urine relative to plasma if Isosthenuria

Answer 2

1.008 to 1.012

Question 3

What is the specific gravity of urine relative to plasma if Hypersthenuria

Answer 3

1.030 to 1.055

Question 4

Causes of Polyuria / polydipsia in the dog

Answer 4

Diabetes mellitus
Renal failure
Hyperadrenocorticism
Hypercalcaemia
Neoplasia
Liver failure
Pyogenic foci
Diabetes insipidus

Question 5

Causes of Polyuria / polydipsia in the cat

Answer 5

Renal failure
Hyperthyroidism
Diabetes mellitus
Pyogenic foci (CBA)
Liver failure
Neoplasia

Question 6

Causes of hyposthenuria

Answer 6

Loss of conc gradient-diuresis/hypoadrenocorticism
Loss of ADH or receptors- primary diabetes insipidus
Antagonism of ADH- Hyperadrenocorticism
Excessive water consumption

Question 7

Causes of isothenuria

Answer 7

Loss of nephrons/Normal

Question 8

Causes of Hypersthenuria

Answer 8

Decreased renal perfusion

Question 9

Most dogs with PUPD have a normal SG of urine (T/F)

Answer 9

True!

Question 10

SG of 1.008 – 1.035 excludes diabetes insipidus (T/F)

Answer 10

True!

Question 11

No glucose in urine excludes diabetes insipidus (T/F)

Answer 11

True!

Question 12

High levels of liver enzymes in a biochemistry test suggest a cause of PUPD (T/F)

Answer 12

False! Every disease cause liver disease. Test also does not test liver function.

Question 13

Diabetes insipidus-

Answer 13

Lose ADH hormones (DDAVP)

Question 14

What does the water deprivation test differentiate

Answer 14

Diabetes Insipidus and Psychogenic polydipsia

Question 15

Indications for water deprivation test

Answer 15

Severe PU/PD
Normal renal function
Not hypercalcaemic
Not hyperglycaemia
Not hypercortisolaemic

Question 16

Summarise water deprivation test

Answer 16

Phase 1 - water restriction
Phase 2 – water deprivation- dehydrate 5.8% of body weight
Empty bladder and weigh every 2 hours
Check urea and creatinine every 2 hours
Preserve urine and plasma samples

Question 17

What is DDAVP

Answer 17

Desmopressin

Question 18

Why is rectal exam relevant for PUPD cases

Answer 18

Anal adenocarcinoma release hormones cause hypercalcaemia causing PUPD

Question 19

Why is thyroid exam relevant for PUPD cases

Answer 19

Hyperthyroidism esp cats cause PUPD

Question 20

Top 3 Important tests in PUPD (Bloods)

Answer 20

Glucose
Calcium
Urea and Creatinine

Question 21

Does high liver value mean anything in a PUPD case

Answer 21

Not really, high liver values happens in most systemic diseases and does not measure liver function. It will be high anyway

Question 22

What could neutrophilia with left shift be diagnostic with patient with PUPD when doing cytology

Answer 22

Pyogenic focus

Question 23

What could neutrophilia with lymphopenia be diagnostic with patient with PUPD when doing cytology

Answer 23

Hyperadrenocorticism

Question 24

Why could survey radiographs be important in PUPD patients

Answer 24

Picture non palpable lymph nodes
Neoplasia- Metastatic
Changes in organ size e.g Pyometra

Question 25

Is ultrasound a good diagnostic tool in PUPD patients

Answer 25

Limited value in survey scans but good when disease is identified
Hard to do

Question 26

How to differentiate between central and nephrogenic diabetic inspidious

Answer 26

Central DI will respond to water deprivation test ( USG will increase after administering DDAVP)