Routine Urinalysis Flashcards
What is the number one body fluid likely to be helpful in the evaluation of patients for urinary disease?
Urine
What are the 3 different methods of urine collection?
- Free Catch
- Catheterization
- Cystocentesis
Pros:
- No risk of complications
- Sample may be collected by client
Cons:
- Subject to contamination by the urethra and genital tract
Free Catch - Midstream voided sample
Pros:
- Simple to perform
- Can get sample even when bladder is small
Cons:
- Risk of introducing urinary tract infection especially in female dogs (approximately 20% risk in females) following a single catheterization; far more risk when urinary catheter is indwelling
- May result in increased numbers of red cells and epithelial cells in the sediment due to micro-trauma from catheter
- Fairly technically easy in male dogs, requires anesthesia/sedation and skill in female dogs and female and male cats
Catheterized Sample
Which method of urine collection is considered routine for use in dogs and cats, and for some ruminants and foals with ultrasound guidance?
Cystocentesis Sample
Pros:
- No risk contamination by urethra or genital tract
- Simple to perform when the bladder is palpable with ultrasound guidance
- Negligible risk of introducing infection
- Useful in animals at high risk for infection (e.g. those with diabetes mellitus or hyperadrenocorticism)
- Well-tolerated by both dogs and cats
- Ultrasound guidance can be helpful in gaining sample when bladder is not full
- “Blind” techniques for sample collection are successful in about 50% of the attempts
Cons:
- Possibility of introducing red cells in the sediment due to iatrogenic trauma
- Theoretical risk of leakage of urine from bladder
- Potential risk of puncturing other abdominal viscera
- Methods for use in horses or ruminants have not been developed; ultrasound guidance for collection in foals and small ruminants is a possibility
Cystocentesis Sample
(T/F) You don’t have to report how the sample was obtained
False
What is the only portion of the urinalysis that provides information about a level of renal function?
Specific Gravity
What are the three components of a complete urinalysis?
- Urine Collection
- Perform Urinalysis
- Interpretation of the Urinalysis
is a reflection of the total solute concentration in urine
Specific Gravity (SpG, USG)
Which of the following represents more severe proteinuria:
Scenerio 1- 4+ or 1000 mg/dL protein in 1.045 urine
Scenerio 2- 4+ or 1000 mg/dL protein in 1.010 urine
Scenerio 2
Defined as elevation, or buildup of, nitrogenous products (BUN-usually ranging 7 to 21 mg/dL), creatinine in the blood, and other secondary waste products within the body
Azotemia
What do you do when refractometer won’t read high enough?
Dilute sample 1:1 with distilled water and double the last 2 digits
Specific gravity tends to be _______ in puppies under three weeks of age, even if they are dehydrated.
low (1.018 -+ 0.010)
When the SpGr is anywhere from 1.007-1.008 up to 1.012- 1.015, it is known as:
Isosthenuria
Urine Osmolarity = ______________
Plasma Osmolality
In a Chemistry (Dipstrip) we mostly pay attention to?
- pH
- Protein
- Glucose
- Ketones
- Occult Blood
- Bilirubin
- WBC’s
In a Chemistry (Dipstrip) we mostly pay attention to?
- pH
- Protein
- Glucose
- Ketones
- Occult Blood
- Bilirubin
- WBC’s (not as useful)
The normal urine pH of carnivores (eg, dogs, cats) is:
5.0-7.5 (acidic)
The normal urine pH of herbivores (eg, horses, cattle, small ruminants)
is:
7.5-8.5 (alkaline)
the period or condition of increased alkalinity of the body fluids and urine during digestion associated with the loss of acid by secretion of gastric juice
Alkaline Tide
(1) Meat diet
(2) Administration of acidifying agents
(3) Metabolic acidosis
(4) Respiratory acidosis
(5) Paradoxical aciduria in metabolic alkalosis with potassium and chloride depletion
(6) Protein catabolic states
Causes of acidic urine pH
(1) Plant based diet
(2) Urine allowed to stand open to air at room temperature
(3) Post-prandial alkaline tide
(4) Urinary tract infection by a urease-positive organism
(5) Administration of alkalinizing agents
(6) Metabolic alkalosis
(7) Respiratory alkalosis
(8) Distal renal tubular acidosis
Causes of alkaline urine pH
The protein pad on the dipstick detects ______ more than it detects _______
albumin, globulin
What is something that can falsely elevate the protein in the urine?
Red Blood Cells in the Urine, but there has to be enough blood in the urine to make the urine look reddish or pink
or
significant pyuria
There is _____ of creatinine in very concentrated urine and there is ______ creatine in very dilute urine
a lot, less
What are the three categories of proteinuria?
- Pre-glomerular proteinuria
- Post-glomerular proteinuria
- Glomerular proteinuria
Functional (also called physiologic). Usually benign and transient. Abates when the underlying cause is corrected—poorly documented in veterinary medicine as a cause of proteinuria.
Pre-glomerular proteinuria
Overload. Tubular resorptive capacity for certain proteins is exceeded when serum concentrations of these proteins become abnormally increased. The amount that passes into the glomerular ultrafiltrate is greater than the resorptive capacity of the tubules, and thus the urine concentration of these proteins increases.
Examples:
- Bence Jones
- Hemoglobinuria
- Myoglobinuria
Pre-glomerular proteinuria
If the sediment is active (i.e. other cellular elements
are evident), and proteinuria is mild to moderate, consider inflammatory renal disease or disease of the lower urinary tract or genital tract
Post-glomerular proteinuria
Disruption of the normal filtration barrier. Persistent proteinuria in the absence of hyperglobulinemia, hemolysis, or muscle damage, and when no other urine sediment abnormalities are evident, is highly suggestive of glomerular disease.
Glomerular proteinuria
Can be a marker of inflammation in the Urinary Tract, Kidney Disease, or Systemic Inflammation
Proteinuria
(must rule out urinary tract disease before looking at systemic disease)
___________ is almost completely reabsorbed from the glomerular filtrate in the Proximal Tubules and is not normally present in the urine of dogs and cats.
Glucose
What is the plasma glucose renal threshold for a dog?
approximately 180 mg/dl
What is the plasma glucose renal threshold for a cat?
approximately 300 mg/dl
____________ is a major abnormal finding in results of urinalysis. Documentation of ______________ obligates consideration of diabetes mellitus as the clinican’s number one disorder to confirm or deny
Glucosuria
Presence of glucosuria with normoglycemia indicates a _________________ problem
Proximal Tubular
_______________ are the products of exaggerated and incomplete oxidation of fatty acids. They are not normally present in the urine of dogs and cats.
Ketones
Inadequate consumption of carbohydrates or impaired endogenous utilization of carbohydrates for energy can increase oxidation of fatty acids. Incomplete oxidation of fatty acids leads to _____________ production.
ketone
The ketone pad on the Dipstick DOES NOT detect which of the following?
- Acetoacetate
- Acetone
- beta-hydroxybuterate
beta-hydroxybuterate
(1) Diabetic ketoacidosis (most common)
(2) Starvation or prolonged fasting in an immature animal
(3) Glycogen storage disease
(4) Low carbohydrate, high fat diet (the Atkins diet)
(5) Persistent hypoglycemia
Causes of ketonuria
Bilirubin in what species is NEVER normal?
Cats
If the urine is still pink after centrifuging it, then it is probably ______________
free hemoglobin
(T/F) Normal urine contains very few elements and very little should be seen microscopically
True
the presence of pus in the urine, typically from bacterial infection
Pyuria
Sediment Examination
RBCs
WBCs
Epithelial Cells
Casts
Crystals
Bacteria
Other
Average 10 fields
What are some causes for erythrocytes (RBCs) in the urine?
- Inflammation
- Glomerular or tubular damage
- May see more in cystocentesis or catheterization sample
What would you might want to do if you see abnormal levels of red blood cells?
Does this animal have urinary tract infection?
if yes, consider culture and/or imaging
If a young cat has blood in the urine, what is one thing that you know for sure?
That it is not associated with UTI
What can give you an idea of where the blood might be coming from?
timing of blood in the urine stream may be a clue as to its source
How many WBCs might you see on a cystocentesis sample?
0-3/hpf
How many WBCs might you see on a n free catch or catheterized sample?
5-8/hpf
What might happen to WBCs if there is a UTI?
Clumping
(T/F) WBCs always indicate infection
False
- do not always indicate infection, can just mean inflammation
What are reasons for seeing renal tubular cells?
- Indicate that something nasty has happened, to the kidneys and killed off a bunch of the tubular lining in the nephrons
- Can also be seen with Glomerulonephritis, Nephrotoxic drugs, and Heavy metals
When should you be concern when seeing transitional epithelial cells?
If you see clumps of them, it may also indicate TCC (cancer)
are pure protein precipitates (Tamm-Horsefall mucoprotein)
Hyaline casts
- Renal trauma
- Post biopsy
- Glomerulonephritis
- Strenuous exercise
- Acute tubular necrosis
RBC Casts
- Pyelonephritis
WBC Casts
Granular Casts are basically _______________ cellular casts
degenerating
(T/F) The presence of crystals in the urine indicate disease
False, it does not indicate disease
(T/F) Struvite and Calcium Oxalate crystals are not necessarily indicative of disease or of potential for urolithiasis
True
When is seeing crystals Significant?
- If seen in a patient who is a known stone-former
- Patient with lower urinary tract signs
- Male cat with history of plug formation/obstruction
- Persistent, significant Crystalluria noted
- Urate and Cystine Crystals
What are two Crystal materials that SHOULD NOT be in the urine?
Urate and Cystine Crystals, that actually indicates a potential problem
Crystals in Acid Urine
* Congenital defect in aa transport
* Dalmatians, Eng. Bulldogs
* Portosystemic shunt
* Liver disease
Amorphous Urate/Urates
Crystals in Acid Urine
* In-born tubular defect
* High risk for stone formation
Cystine
Crystals in Acid Urine
* Dihydrate
* ½ of cystic calculi in cats
* Monohydrate
* ethylene glycol toxicity sometimes
Calcium oxalate
- Amorphous phosphate
- Calcium carbonate (horses, GPs)
- Calcium phosphate
- Ammonium biurate
* Hepatic disease
* Uricase transport defect
* May not be significant in
cats
Crystals in Alkaline Urine
Crystals in Alkaline Urine
–Dry cat diets
–High starch & fiber diets stimulate formation
–½ of cystic calculi in cats
–≥ ½ of the calculi in dogs
–Urinary infection with urease
splitting bacteria (more later)
Magnesium ammonium phosphate (struvite)
What can it be when you see bacteria in the urine with no WBCs?
- Contaminant
- Asymptomatic bacteria urea (not an urinary tract infection)
