Lecture 1 - Part 2: Physical Properties Urinalysis

What are some of the physical characteristics measured in a urinalysis?

Colour, transparency, odour, volume, specific gravity (USG)

What are some of the chemical characteristics measured in a urinalysis?

Protein, glucose, ketones, bilirubin, occult blood, pH

What are some additional tests that can be done in a urinalysis?

- Culture and sensitivity;

- Urine protein to creatinine ratio;

- Evaluation or urinary calculi/ plugs;

- Neoplasia tests

What colour should the urine of a healthy dog or cat be?

Light yellow to amber

What colour could the urine of a healthy rabbit be?

varies from yellow to white but may turn orange-red-brown depending on diet

What colour could the urine of a healthy horse be?

yellow but often turns brown upon standing due to oxidation

What might orange urine indicate?

Bilirubinuria

What might pink-red or red-brown urine indicate?

Hematuria, hemoglobinuria, or myoglobinuria

How would hematuria appear after centrifugation?

Clear supernatant with a RBC pellet

How would hemoglobinuria appear after centrifugation?

Red to red-brown supernatant with no RBC pellet

How would myoglobinuria appear after centrifugation?

Red-brown to brown supernatant with no sediment

What can cause myoglobinuria?

Severe muscle damage - equine exertional rhabdomyolysis

What are some terms that can be used to describe urine transparency?

Clear, slightly cloudy, cloudy, turbid/ opaque

What type of transparency might be seen in a healthy dog urine sample

Clear when fresh

What type of transparency might be seen in a healthy horse urine sample

Cloudy

What type of transparency might be seen in a healthy rabbit, hamster, or guinea pig urine sample

Slightly cloudy

What type of transparency might be seen in a healthy feline urine sample

Slightly cloudy due to fat

What are some causes of turbid urine? (List at least 3)

Cells

Cellular debris

Crystals

Bacteria

Casts

Mucus

Sperm

Lipids

Feces

What might a fruity/sweet smelling urine indicate?

- Ketosis in cows;

- Pregnancy toxemia in ewes;

- Diabetic ketoacidosis in dogs and cats

What factors can affect urine odour?

Health, medications, and diet

What factors can affect urine volume?

Fluid intake

Fluid loss (e.x V/D)

Diet (e.g. wet food vs dry)

Activity

Size of animal

Species

Environmental conditions (e.x. high temperatures/ fever)

What is the normal urine volume of a cat?

10-20 ml/kg/day

What is the normal urine volume of a dog?

20-100 ml/kg/day

What is the normal urine volume of a horse?

3-18 ml/kg/day

What is the normal urine volume of a cow?

17-45 ml/kg/day

What is urine specific gravity a measurement of?

The concentration of solutes in a sample and the ability of the kidneys to concentrate or dilute urine compared with the SG of plasma

What are some tools that can be used to measure specific gravity?

Refractometer, urinometer, and reagent strips

What effect would a large amount of protein or glucose have on the USG?

Increase USG

True or False: a canine urine sample with a USG of 1.040 is considered healthy

True - 1.030 or higher is considered healthy

3 multiple choice options

True or False: a feline urine sample with a USG of 1.025 is considered healthy

False - 1.035 or higher is considered healthy

3 multiple choice options

True or False: an equine or ruminant urine sample with a USG of 1.025 is considered healthy

True - 1.020 or higher is considered healthy

3 multiple choice options

What would a low USG and azotemia indicate?

Renal failure

True or False: most neonates (except calves) do not have efficient concentrating mechanisms

True

1 multiple choice option

What is hypersthenuria?

USG is greater than SG of plasma - this is normal/ healthy

What USG level would we expect to see in a dog with hypersthenuria?

USG greater than or equal to 1.030

What USG level would we expect to see in a cat with hypersthenuria?

USG greater than or equal to 1.035

What USG level would we expect to see in a horse or ruminant with hypersthenuria?

USG greater than or equal to 1.020

What does it mean for a urine sample to be of minimal concentration?

Urine is inappropriately dilute compared with plasma

What USG level would we expect in a minimal concentration canine urine sample?

1.012 - 1.030

What USG level would we expect in a minimal concentration feline urine sample?

1.012 - 1.035

What USG level would we expect in a minimal concentration equine or ruminant urine sample?

1.012 - 1.020

What is isosthenuria?

The SG or the urine and plasma are the same

What USG level would we expect in a dog or cat with isosthenuria?

1.008 - 1.012

What is hyposthenuria?

USG is lower than SG of plasma

What USG level would we expect in a cat or dog with hyposthenuria?

Less than 1.008