Endoscopy and Urine sampling

Question 1

What is Urethroscopy?

Answer 1

Looking into the urethra with an endoscope

Question 2

What is Cystoscopy?

Answer 2

Looking into the bladder with an endoscope

Question 3

What are the two types of cystoscopy?

Answer 3

Transurethral cystoscopy

Prepubic percutaneous cystoscopy (Puncture the skin eg if there is a blockage)

Question 4

What endoscope would you use in a bitch bladder?

Answer 4

Rigid or semi-rigid endoscopes with sheath

Question 5

What endoscope would you use in a male dog bladder?

Answer 5

Flexible endoscopes

Question 6

What must we do to view the detail of the urethra?

Answer 6

Fluid irrigation (with saline)

Question 7

What will we carry out in a full urinalysis?

Answer 7

Macroscopic examination (colour, transparency/turbidity)
Microscopic examination (preferably undertaken by experienced personnel)
Chemical examination (dipstick tests and urine specific gravity)
Microbiological examination by culture

Question 8

How can we collect urine?

Answer 8

Midstream Sample Urine (MSSU) - grab urine from peeing animal
Cystocentesis
Catheterisation

Question 9

What are the advantages of Midstream Sample Urine (MSSU)?

Answer 9

Easy (generally) and may be left to owner (naturally voided - dog)
Non-traumatic
Use of modified litter tray using glass beads can be used for initial screening of cats

Question 10

How do we manually express the bladder for a MSSU?

Answer 10

Manually compressing the bladder may induce the micturition reflex
More effective in small dogs and cats
Bladder must contain reasonable volume of urine
Direct compression towards neck of bladder

Question 11

What are the disadvantages of MSSU?

Answer 11

Risk of non-compliance, resentment (dog)
Need to avoid residue at end of urination, i.e. bacteriology required
Risk of haematuria and bladder rupture with manual expression
Variable volume
Risk of faecal contamination/sample unsuitable for culture

Question 12

What are the advantages of cystocentesis?

Answer 12

Quick with no need to wait for spontaneous urination
Aseptical collection with no urethral contamination (so ideal for culture)
Easy to perform when bladder moderately distended and patient (dog or cat) adequately restrained
Lower risk of iatrogenic haematuria (cf. catheterisation)

Question 13

What are the disadvantages of cystocentesis?

Answer 13

Requires some experience
Needs adequate volume of urine in bladder
Iatrogenic micro-/(macro-)scopic haemorrhage possible
Contraindicated if:
bladder severely diseased – risk of rupture or clotting problems

Question 14

What are the advantages of catheterisation?

Answer 14

No need to wait for spontaneous micturition
Relatively, rather than absolutely, free of risk of bacterial contamination
Usually an ample sample volume

Question 15

What are the disadvantages of catheterisation?

Answer 15

Some experience and a suitable speculum/light source may be needed (bitch)
Risk of iatrogenic infection, haematuria +/- mucosal damage (with some modification of urine cytology findings)
Cost of equipment and disposable catheter

Question 16

What are the advantages of collecting urine in the early morning or after fasting?

Answer 16

Most concentrated sample (relative water deprivation overnight) – evaluates concentrating capacity
Gives the highest yield of cells, casts and bacteria

Question 17

What are the disadvantages of collecting urine in the early morning or after fasting?

Answer 17

Glucosuria may be less obvious than in a post-prandial sample
Cytology – cells may be altered due to prolonged exposures to variations in pH and osmolality

Question 18

What are the advantages of sampling recently formed urine?

Answer 18

Cells more easily recognisable on microscopy

Fastidious bacteria which are inhibited by urine may be easier to detect

Question 19

What are the disadvantages of sampling recently formed urine?

Answer 19

Sample more dilute as animal has drunk recently – concentrating ability more difficult to assess
More dilute samples may cause lysis of cells

Question 20

What tube should we put the urine into?

Answer 20

Plain sample (no additive)
Boric acid (preserved)
Formaldehyde (cytology)

Question 21

If we have to do the urinalysis after 1 hour post collection how should we store the urine?

Answer 21

Preferably < 1hr post collection

Otherwise refrigerate and warm to room temp before analysis

Question 22

What do we look at during macroscopic urinalysis?

Answer 22

Colour: Light yellow or amber
Odour: Should not be offensive
Transparency/turbidity: Concentrated and end flow samples more likely to be turbid

Question 23

What do we look at during routine urine chemistry?

Answer 23

Specific gravity (SG)
pH
Dipstick tests for protein, glucose, ketones, bilirubin, blood, leukocytes

Question 24

What do we look for on microscopic urine examination?

Answer 24

Crystalluria
Renal tubular casts
Epithelial cells
Blood cells
Bacteria

Question 25

What causes Crystalluria?

Answer 25

When urine saturated with dissolved minerals these crystals precipitate out
Cold temperature/prolonged storage increases formation in vitro – so use fresh, non-refrigerated sample within 1 hour

Question 26

What are renal tubular casts?

Answer 26

Proteinaceous plugs of dense, mesh-like mucoprotein +/- cells accumulate in distal portion of renal tubule

Question 27

Are epithelial cells in the urine normal?

Answer 27

Up to 2 per field 
Try to ID type of cell:
Transitional cells (renal pelvis, ureter, bladder, proximal 2/3 urethra
Squamous cells (distal to above)

Question 28

What container should we put urine in to culture bacteria?

Answer 28

Usually boric acid container