Methods of urinalysis

General info about urine

• Kidneys are big filters

• Make sure we are excreting what we want to

• Pulls back in what we don’t want to be excreted e.g. glucose

• Urethra is where excretion takes place

What are the 4 different methods of urine collection

• Free catch

• Catheter (rigid or foley)

• Cystocentesis

• Manual expression

What is the different between rigid and foley catheters

• Rigid-short use

• Foley-long use

What is the purpose of taking a urine sample

• To determine kidney functions-dipstick, SG, cytology

• Presence of urine crystals-cytology

• Presence of infection—dipstick, cytology

• Glucose-dipstick

• Hydration-SG

• Presence of blood in urine-dipstick, cytology

What is normal urine output for cats

18-25mls/hr

What is the normal urine output for dogs

20-40mls/hr

What is the golden rule for urine output

1-2mls/kg/hr

What are the free flow sample rules

• If obtaining from horses or dogs make sure it is mid flow-avoids getting old urine and decreases contamination

• Always take a urine sample before starting treatment as can affect results

• Can be useful to collect urine sample at same time as other tests-compare results

What equipment do you need to take a free catch

• Gloves

• Kidney dish

• Syringes

• Urine pot

What are the advantages of free catch

• Non invasive

• Owners can do it

• Simple

• Cheap

What are the disadvantages of free catch

• Risk of contamination-unsuitable in leptospirosis patients or those with urine infections

• Can take forever-waiting for animal to pee

• Getting owners to bring in suitable pots and right away can be challenging

• Can’t do urinary culture as urine will be contaminated

What equipment do you need for manual expression

• Non-sterile gloves

• Kidney dish/litter tray

• Syringes

• Inco pads

• Handler

• Urine pot

What are the advantages of manual expression

• Non invasive

• Good for neurological patients

• Quick once they have a full bladder

• Can be done conscious

• Can measure urine output

What are the disadvantages of manual expression

• Risk of contamination-non sterile sample

• Not suitable for culture

• Not suitable for blocked patients

• Not suitable for those who have had abdominal surgeries, coagulapothy issues or overweight 

• Requires skill

What equipment do you need for cystocentesis’

• Sterile gloves

• Syringes

• Needles

• Urine pot

• Vet

• Spirit

• Ultrasound

What are the advantages of cystocentesis’

• Quick

• Sterile sample

• Bladder decompression

What are the disadvantages of cystocentesis’

• Vet only

• Bladder trauma

• Can cause trauma to other organs

• Requires skill

• Uncomfortable

• Might need sedation

What equipment do you need for short term catheters

• Sterile gloves

• Lube-KY jelly

• Assistant

• Rigid catheter

• Kidney dish

• Can use a syringe

• Speculum if female

• Dilute hibi to clean

What are the advantages of short term catheters

• Sterile sample

• Don’t need to wait for a big bladder

• Suitable for blocked pateints

• Nurse or vet

What are the disadvantages of short term catheters

• Females must have sedation

• Not suitable for coagulopathic patients

• Can cause urethral trauma

• Expensive

• Risk of introducing infection

What equipment do you need for indwelling (long term) catheters

• Guide wire

• Sterile gloves

• Suture material-normally for cats

• 5mls of water for ballon (depends on size of ballon)

• Urine collection bag

What are the advantages of indwelling urinary catheters

• Sterile sample

• Don’t need to wait for patient to urinate

• Can use for blocked patients

• Can measure urine output over long period of time

What are the disadvantages of indwelling catheters

• Expensive

• Require skill

• Uncomfortable

• Not suitable for coagulopathic patients

• Patient interference-BC

• Risk of introducing infection

What are the differences between plain tubes and boric acid tubes for storing urine

• Plain tubes must be processed within 2 hours (room temp) or refrigerate for 24 hours

• Plain tubes cannot be used for urine culture if sample is over 24 hours old

• Boric acid tubes prevent bacterial overgrowth if above 24 hours to analysis

What factors do we need to make a diagnosis using urine

• Patient history-clinical signs, changes in output etc

• Urinalysis

• Physical examination-abdominal palpation

• Definitive diagnosis must have ultrasonography urinary tract, radiography, contrast radiography

what initial assessments of we make (macro analysis)

• Colour

• Smell

• Amount

• Turbidity-cloudiness

What species have cloudier urine

Horses and rabbits

What can we use to measure the volume of urine

• Syringe-smaller animals

• Jug

• Catheter bag

What does anuria mean 

• Not enough urine

• <0.5mls/kg/hr

What does oliguria mean

• Lack of urine

• 0.5-1ml/kg/hr

What does polyuria mean

• >2mls/kg/hr

What does light yellow urine mean

• Normal

• Low concentration

What does yellow urine mean

• Normal

• Normal concentration

What does amber urine mean

• Normal

• High concentration

• Can be presence of bilirubin

What does red urine mean

• Haematuria

• Haemoglobinuria- presence of haemoglobin as RBCs have broken down

What does brown urine mean

• More common in equine

• Myoglobin is muscle damage

• Methaemoglobin is common in cats

• Bilirubinuria is hepatic or bilirubin disease

What is the difference with rabbit urine

Colourful anyway and depends on what they eat

What does clear urine mean

What does slightly cloudy urine mean

What does cloudy urine mean

What does turbid urine mean

How do you obtain smell of urine

• Waft in front of nose

• DO NOT put nose into the pot

What urine has a stronger smell

Concentrated urine

What does bacterial infection urine smell like

Can smell like faeces

What does toxins smell like in urine

Ketones can smell like pear drops

What are the urine requirements for dipsticks

• Warm refrigerated urine prior to testing

• Don’t dip a dipstick, use a pipette

What are the advantages of dipsticks

• Rapid results

• Non-invasive

• Good early indicator

• Can give pre-clinical signs data

What are the disadvantages of dipsticks

• Not reliable for SG

• Timings

What do we ignore on dipsticks

• Urobiligen

• TS

• Nitrates

• Leukocytes

Which animals have acidic urine

Dogs and cats

Which animals have alkaline urine

Cows and horses (above 8.5)

More pH info

Which urine protein is primarily detected

Albumin

More urine proteins