Urinalysis sample collection and handling procedures

what is the very first step in performing a complete urinalysis?

proper sample collection

ideally, urine samples should be collected before the administration of______.

therapeutic agents

why are morning urine samples preferred for analysis?

they are the most concentrated samples

besides morning collection, when is a urine sample most concentrated?

after several hours of water deprivation

what are the three main techniques for collecting urine?

bladder expression, catheterization, and cystocentesis

what is the primary diagnostic limitation of a voided (free catch) urine sample?

contamination by the distal genital tract

why should samples not be used for bacteriologic examinations?

they are frequently contaminated by bacteria in the distal tract

how does inflammation in the distal genital tract affect a free catch urine sample?

it can lead to an increased white blood cell count

when performing a free catch, what type of container is required?

a clean but non-sterile container

what is the purpose of cleaning the vulva or prepuce before a voided collection?

to decrease contamination of the sample

which portion of the urine stream is best for a voided sample collection?

midstream

why is a midstream urine sample preferred over the initial stream in free catch?

it contains less contamination from the distal tract

what tool is commonly used to facilitate voided collection in dogs?

ladles or cup on poles

how can a voided urine sample be collected from a cat?

by using nonabsorbent granules in the litter box

what technique is used to induce voiding in cattle?

rubbing straw or a hand ventral to the vulva in a circular fashion

how is urine collection induced in sheep?

by occluding the nostrils

what physical stimulation can be used to collect urine from a horse?

rubbing a warm cloth on the ventral abdomen

besides physical stimulation, how can urine be collected from a horse?

by placing the animal a clean stall with fresh hay

what is the technique of manually compressing the bladder to collect urine called?

bladder expression

bladder expression is unsuitable for which type of laboratory test?

bacterial culturing

in what positions can an animal be placed for manual bladder expression?

standing or lateral recumbency

what type of pressure should be applied during manual bladder expression?

gentle but steady pressure

what is the primary risk of using excessive force during bladder expression?

bladder rupture

under what clinical condition is manual bladder expression strictly contraindicated?

urethral obstruction

urinary catheterization involves the insertion of a catheter through the_____ and into the bladder.

urethra

what materials are typically used to manufacture urinary catheters?

polypropylene or rubber

what is required for the catheterization procedure to prevent introducing infection?

a sterile technique

what must be applied to a urinary catheter before insertion to prevent trauma?

lubrication

why should the first portion of urine collected via catheterization be avoided?

it may contain increased RBCs and epithelial cells from the procedure

what size polypropylene catheter is most commonly used in dogs?

4 to 10 Fr

what specific catheter type and size is used for male cats?

3 ½ Fr tom cat catheter

when catheterizing a male cat, how is the penis extruded?

by pushing the penis caudally and pulling the prepuce forward

what tool is used to visualize the urethral orifice during catheterization of a female dog?

a vaginal speculum

in a female dog, the urethral orifice is located on the____ floor of the vagina.

ventral

which collection method is used to obtain sterile samples for culture and sensitivity?

cystocentesis

what physical requirement must the bladder meet before performing cystocentesis?

it must be sufficiently distended

what imaging tool can be used as a guide during cystocentesis?

ultrasound

what needle size is typically used for cystocentesis in small animals?

22 or 22 gauge

what is the standard needle length for cystocentesis?

1 to 1 ½ inch

why must the needle never be redirected once it has passed through the skin during cystocentesis?

to avoid damaging internal organs

when should suction be released during a cystocentesis procedure?

after the sample is obtained but before withdrawing the needle

at what angle should the needle be directed through the bladder wall during cystocentesis?

an oblique angle

within what timeframe should urine be analyzed to avoid artifacts?

30 minutes to 1 hour

if immediate analysis is impossible, how long can urine be refridgerated?

6 to 12 hours

which specific urinalysis parameter should be measured before refrigerating the samples?

specific gravity

what artifact commonly forms when urine is cooled?

crystals

what must be done to a refrigerated urine sample before evaluation?

warm it to room temperature

how should a urine sample be handled immediately before evaluation to ensure consistency?

gently mix the sample

how does leaving urine at room temperature for too long affect glucose concentrations?

concentrations decrease

what happens to the pH of a urine sample if it is not refrigerated?

the pH increases

how does delayed analysis at room temperature affect red blood cells and casts?

they begin to break down

what biological process increases in a urine sample left at room temperature?

bacteria growth

when using formalin for preservation, what is the required ratio?

1 drop of 40% formalin per 1 oz of urine

what test must be performed before adding formalin to a urine sample?

glucose test

how is toluene used as a urine preservative?

it is added to form a layer on top of the sample

what chemical can be added in a 1:9 ratio to preserve urine for reference laboratories?

5% phenol

what single solid additive can be used to preserve a urine specimen?

one thymol crystal

what info must always be noted regarding the urine samples’s origin?

the method of collection