Urinary

The renal tubular system can absorb yp to ____ of the water in the glomerular filtrate

99%

T/F: the renal system maintains normal extracellular K+ concentration

true

_____ is formed in the kidney secondary to decreased oxygen tension & released into blood where it stimulates RBC production in the bone marrow

erythropoietin

kidneys are a sure conversion of ____ to its most active form which aids with intestinal calcium aborsption

Vitamin D

passive process which is the selective excretion of water & solutes in the kidney

glomerular filtration

the rate at which plasma filtrates over into the kidney & is greatly affected by renal plasma blood flow

glomerular filtration rate (GFR)

process in the kidneys which is active or passive & responsible for managing amino acids & glucose levels through the proximal tubule

tubular resportion

ADH and aldosterone act on the ___ of the kidney

collecting ducts

the urine collection container needs to be ___ for culture

sterile

method of urine collection which has a higher chance of contamination from external genitalia and you are trying to catch mid-stream

free flow

true/false: artifactual hemorrhage and squamous or epithelial cells may be seen with urinary catheterization

true

Method of urine collection which is the gold standard for culture as it is the most likely to be sterile. May still pick up skin bacteria or potential enterocentesis

cystocentesis

Increased volumes being produced and eliminated from the body

polyuria

Production of decreased volumes of urine and/or eliminated of urine

oliguria

no urine being produced or eliminated from the body

anuria

classification of cloudy urine where the letters of a paper are visible but cannot be read

moderately cloudy

Classification of cloudy urine where the letters of a paper are still able to be read

slightly cloudy

Classification of cloudy urine where you cannot see the letters of a paper through it

markedly cloudy

T/F: Slightly cloudy urine is normal in all species except horses

false; only horses should have slightly cloudy urine, all other species should have clear urine

T/F: Normal urine can vary from clear to more of an amber colour depending on concentration

true

Pigmenturia due to erythrocytes, myoglobin, or hemoglobin in urine

red to brownish

pigmenturia due to methemoglobin

dark brown to black

T/F: Aged urine samples can give a foul odour

true

Sweet smell to urine that can be detected by some people

ketonuria

Estimate of urine concentration based on the number and molecular weight/size of particles

urine specific gravity (USG)

Used to measure USG

refractometer

T/F: USG should not be done on the supernatant

false

T/F: Normal USG values can be varied based on the patient's hydration status

true

Normal range for USG

1.001-1.060

USG range for isothernuria

1.008-1.012

USG for hyposthenuria

<1.008

USG value in dogs which shows adequate renal concentrating ability

>1.030

USG value in cats which shows adequate renal concentrating ability

>1.035

USG value in cattle & horses which shows adequate renal concentrating ability

>1.025

T/F: If a patient has a random low USG but is otherwise clinically normal and biochemistry values are normal then you should recheck the USG at another time as it may be a chance finding

true

T/F: If USG is higher than normal for the species and they're dehydrated then this suggests a tubular concentrating problem

false

4 causes of impaired ability to concentrate urine

central DI, nephrogenic DI, solute overload, decreased medullary hypertonicity

T/F: Chemical analysis of urine should be done in light of the USG

true

Carnivores and suckling herbivores have ____ urine pH

acidic

Adult herbivores have _____ urine pH

alkakline

The following are all causes of this urine pH anomaly:
- Respiratory and metabolic acidosis
- Hypochloremic metabolic alkalosis
- High protein diets or protein catabolism (starvation)
- Hypokalemia

aciduria

The following are all causes of this urine pH anomaly:
- Urea degradation
- Post-prandial tide (monogastrics)
- Respiratory or metabolic alkalosis

alkalinuria

Urinary ___ is evaluated using urine dipstick, sulfosalicylic acid precipitation or automated chemistry analyzers

protein

T/F: urine dipsticks for protein measure albumin more than globulins

true

alkalinuria & disinfectants can cause ____ on protein dipsticks

false positives

Test for urinary protein where a certain volume of acid is added to the urine sample and if there are proteins in the urine then it will cause them to precipitate out which are then compared to pre-made standards

precipitation by sulfosalicylic acid

The only common domestic species which normally have a small amount of protein present in adequately concentrated urine

dogs

T/F: There is usually a lack of urinary protein in neonates <48hrs old due to absorption of colostrum

false

Which classification of proteinuria do these causes align with?
- Hemoglobinuria
- Myoglobinuria
- Abnormal protein production

pre-renal

Which type of renal proteinuria does this describe?
- Mild and transient
- Stress, pyrexia, strenuous exercise

functional

Which type of renal proteinuria does this describe?
- Glomerular disease
- Tubular or interstitial disease

pathological

Which classification of proteinuria do these causes align with?
- Urinary hemorrhage or inflammation
- Genital hemorrhage or inflammation

post-renal

Increased number of RBCs in urine sediment

hematuria

____ hemoglobinuria is seen with intravascular hemolysis and will see concurrent pink plasma

true

___ hemoglobinuria is due to lysis of RBCs in urine

false

Blood in the urine due to muscle injury

myoglobinuria

Blood in the urine where you expect concurrent hemoglobinuria

methemoglobinuria

Hydrogen peroxide and sodium hypochlorite cause ___ on glucose dip sticks

false positives

The renal threshold of glucose in cats is ____ mmol/L

16.1

The renal threshold of glucose in dogs is ____ mmol/L

9.9-12.2

The renal threshold of glucose in horses is ____ mmol/L

8.3

The renal threshold of glucose in cattle is ____ mmol/L

5.5

If the renal glucose threshold is surpassed, the distal convoluted tubule will no longer be able to reabsorb anything more so you will get...

glucosuria

____ glucosuria is seen when the BG is above the renal threshold

hyperglycaemic

____ glycosuria is seen when the blood glucose is not above the renal threshold

normoglycemic

Ketone which cannot be picked up on a urine dipstick

B-hydroxybutyrate

Ketonuria occurs when animals are in a _____ energy balance

negative

Only ___ bilirubin is excreted in urine

conjugated

Species in which there is normally a small amount of bilirubin present in urine

dog

Conditions which you think of if you have bilirubinuria

hepatobiliary or extravascular hemolysis

Which epithelial cell urine sediment does this describe?
- Large flattened angular cells
-Can be a nuclear but usually have a condensing nucleus
- Do not have clinical significance

epithelial cells

Which epithelial cell urine sediment does this describe?
- Smaller than squamous and more ovoid to polygonal in shape
- Have a round nucleus with size varying
- In health low numbers can be seen in any type of sample
- Can originate anywhere from the kidneys to the proximal urethra

transitional epithelial cells

T/F: Carcinomas are the most common neoplastic cells seen in urine sediments and need to have severe malignant criteria

true

_____RBCs/400x is considered hematuria

>5

If present in urine sediment, can indicate there is a pyuria present may be present with infectious or inflammatory processes

pyuria

Form due to protein leaking from the renal tubules

casts

T/F: Casts can be formed from the proximal tubules

false

Casts are composed of ______ +/- cells

tamm-horsfall mucoproteins

Which urinary casts does this describe?
- Clear and colourless so difficult to diagnose
- Margins are smooth
- Just the Tamm-Horsfall mucoprotein with no cells
- Less than 1-2 at the 10x objective is normal

hyaline casts

Urinary casts which are a continuum as the cast breaks down and may be seen in varying lengths/widths and in low numbers are incidental

renal epithelial, granular & waxy casts

High numbers of renal epithelial, granular, and waxy casts indicate...

renal tubular degeneration or necrosis

Urinary cast which is most commonly seen in felines

fatty casts

Urine sediment finding which are narrow twisted ribbons which stain pale pink

mucus

Urine sediment finding which are varying sized clear spheres that often are found on a different area of focus than the rest of urine findings

lipid

T/F: Knowing the urine sampling method is important to determine the clinical relevance of bacteria

true

T/F: Stored urine can cause crystal precipitation and dissolution

true

Which type of urinary crystal does this describe?
- Yellow
- Typically linear structures and can form clumps but other shapes exist

bilirubin

Which type of urinary crystal does this describe?
- Little square shaped crystals with an x in them
- In health, any species can have small numbers
- If we see really high numbers in small numbers can be seen with ethylene glycol toxicity

calcium oxalate dihydrate

Which type of urinary crystal does this describe?
- Most often rectangular with a coffin lid shape
- Can have an angular shape but should have a linear line up the center
- Can be a shorter shape (more square) but should still have the coffin lid

triple phosphate

Which type of urinary crystal does this describe?
- Tend to be tan-yellowish
- Normal in urine of species that secrete a lot of calcium in their urine (i.e. horses, rabbits, guinea pigs, and goats)
- Most often quite large but smaller clearer ones may also be present (usually forming)

calcium carbonate

Which type of urinary crystal does this describe?
- Crystals that don't have a particular shape
- Type determined by urine pH
- Most often don't have any clinical significance

amorphous urates or phosphates

Which type of urinary crystal does this describe?
- Varying sized tan to sometimes golden yellow spheres
- Sometimes can have projections off them
- Dalmatians or English bulldogs are predisposed
- Other species the primary differential is hepatic dysfunction

ammonia urate

Which type of urinary crystal does this describe?
- Classic form are the "picket fence" shape
- Can also have a dumbbell shape or hemp seed shape
- Low numbers of these can be seen normally
- Don't normally don't see picket fence form in health
- Ethylene glycol is primary differential if high numbers or picket fence shape present

calcium oxalate monohydrate

Which type of urinary crystal does this describe?
- 6 sided clear crystals
- Uncommon but seen with congenital defect in ability to resorb cystine in the proximal convoluted tubule

cystine

T/F: If you see fungal structures or parasites in urine then you should always be concerned about a true urinary infection as stain is always sterile

false

decreased excretion or GFR

renal causes of increased urea

The following are non-renal causes of ____ urea
- Increased protein catabolism
- High protein diet
- Upper GIT hemorrhage as blood is acting like a protein meal

increased

The following cause a ____ in urea
- Decreased hepatic production such as with hepatic insufficiency or dysfunction
- If the patient isn't eating or not able to absorb protein
- If the patient is being diuresed as it increases urea excretion

decrease

Creatinine originates from ___ and is primarily excreted through the kidneys with a small amount excreted through the GIT

muscle

T/F: Increased creatinine is most often due to decreased GFR or decreased urinary excretion

true