Test 2- Urinalysis Flashcards
What is a cystocentesis?
Invasive procedure used to get a urine sample from the bladder of
an animal w/ a needle and syringe. It avoid contamination from the lower Urinary tract, aids in localizing the are of hematuria, pyuria, and bacteriura and be used therapeutically- in blocked cats.
What are contraindications for cystocentesis?
Local pyoderma, coagulopathy, neoplasia, insufficient volume of urine in bladder and patient resists restraint and abdominal palpation. Change needle before transferring to red top Cystos can induce microscopic hematuria on a dipstick esp. in cats. – cysto preferred for culture.
What is voided urine?
Free catch- mid stream flow- you can have contamination.
Generally acceptable for urinalysis, sediment exam. Not suitable
or cultures
What can catheterization result in?
Blood/epithelial cell contamination, trauma, technique difficulty
(esp. in females), track materials into bladder and cause infection, and perform re check UA to check for UTI after catheterization
How do you properly handle urine?
Evaluate w/in 30 mins. Refrigerate. Low USG can lead to cell
lysis so make sure to analyze quickly.
• Refrigerate up to 12 hours in sterile, opaque, airtight container. Warm to room temp for 20 mins, gently swish to remix and resusspend sediment
When looking grossly, what can the color of the urine tell you?
If they are hydrated (mostly will be yellow)
• Yellow orange – bilirubin
• Yellowgreen/yellow brown- bilirubin and biliverdin
• Red- RBC, Hgb, Mgb
• Red-brown- RBC, Hb, Mgb, Met Hgb
• Brown to black- MetHgbw/ hemoglobin- serum also red/pink; myoglobin- does not accumulate in serum so serum will not be discolored; metHgb- serum brown/black
what can the clarity of the gross inspection tell you?
You have clear, slightly cloudy, cloudy, opaque, flocculent (chunky).
• Can have mild turbidity- equine urine tends to be turbid/cloudy.
• Cloudiness or turbidity caused by formed elements, cells,
crystals, bacteria, casts, and lipid droplets (some lipid
normal in cats)
What is USG?
SG created by dissolved ions and molecules. Cells, casts and
crystals are not dissolved. So before reading-s pin the sample,
remove the supernatant- read the USG from the supernatatant.
What is specific about USG temperature ?
Measure on room temp only! cold fluids more dense so can falsely increase the USG
What do you need to interpret the USG along with?
Serum [UN] and [creatinine], amount of urine, and hydration status.
What USG per species demonstrates concentration?
Dog > 1.030, Cat >1.035, Horse > 1.025
On a dipstick, what values did we ignore?
• Leukocytes, USG, Nitrate, urobilinogen
What is specific about dipstick glucose levels?
Not present in healthy individuals, and cold urine can falsely
decrease urine in glucose.
What are the renal tubule thresholds for glucose?
Dog and Horse 180 mg/dl; cat 280 mg/dL ; cattle- 100 md.
What does hypeglycemic glucosuria represent?
Diabetes mellitus (glucose), hyperadrenocroticism (cortisol)
drugs (dextrose, glucocorticoids, progesterone),
postprandial, acute pancreatitis,
extreme stresses pheochromocytoma, glucagonoma, head trauma.
What does normoglycemic glucosuria represent?
Transient stress, reversible tubular damage (drugs, hypoxia,
infection, toxin), cats w/ urethral obstruction (unknown
reason), fanconi syndrome (inherited tubular defect), and primary renal glucosuira
What is specific about dogs and bilirubin concentration in urine?
• Normal to have 1+ bilirubinuria on dipstick for canine (20% normal
dogs). Canine PCT can conjugate and Hgb and excrete bilirubin. IN ANY OTHER SPECIES- bilirubinuria is abnormal
Expect bilirubinuria before bilirubinemia (if you have
2+ bilirubin & USG 1.020- more concerned.
o 2+ bilirubin and USG 1.040- less concerned.
What are causes for bilirubinuira?
Liver disease, bile duct obstruction, starvation, hemolysis,
pyrexia, horses off feed
What can cause a dipstick to be a false positive for [bilirubin]?
Old sample, light exposure, nitrites, ascorbic acid
Are positive ketones normally found on a dipstick test?
No—not present in normal healthy animals.
What are three kinds of ketone bodies. What ketones do they pick up?
B-hydroxyburterate (78%), acetoacetic acid (20%), Acetone (2%)
o Acetoacetic acid and acetone are true ketones (only
detected)
o B-hydroxybuterate is predomiant form of ketone in rumiantns
expect an increase in it in bovine ketosis and pregnancy
toxemia in ewes
What can cause increase dipstick [ketone]?
Excessive/defective lipid or carbohydrate metabolism. Ketonuria
detected prior to ketonemia.
o Ketonuria shows negative energy balance, DKA,
insulinoma
Excessive/defective lipid or carbohydrate metabolism. Ketonuria
detected prior to ketonemia.
o Ketonuria shows negative energy balance, DKA,
insulinoma
Hgb, Mgb, or RBC. RBC lyse and release Hb. Bleach can cause a false positive reaction for blood.
w/ a true hematuria, what occurs after centrifugation of the urine?
The supernatant clears w/ centrifugation. (pellet settles at bottom)
What are causes of hematuria?
Trauma, infection, inflammation, infarction, calculi, neoplasia, coagulopathy
What color does hemoglobinuria present as?
Reddish-brown urine. The urine supernatant is not clear
after centrifugation like you would see w a true hematuria.
No RBC are found in the sediment.
What are causes of hemoglobinuria?
Intravascular hemolysis- the serum will be pink/red and the patient will be anemic
What is myoglobin?
• Small, not protein bound, readily passes glomerular filtration
barrier, no visible myoglobinaemia
• Myocyte damage leads to released Myoglobin. Increase in AST and
creatinine kinase will also be seen on biochem profile and the urine supernatant will have a red color (But serum will not be stained)
What is the normal pH of dog/cat urine!
6.5-7.5
What is the normal pH of a horse &cows urine
7.5-8.5
Renal tubular dysfuncctio can lead to
Renal tubular dysfuncction can lead to a paradoxically alkaline urine
What can an alkaline pH demonstrate?
• UTI (urea splitting bacteria! proteus, pseudomonas,
stphaylococcus)
• Low protein diets (herbivores- diets for chornic cyrstalluria)
• Respiratory alkalosis, metabolic alkalosis (put base out into urine),
• Alkalinizing drugs
What can cause an acidic pH?
• High protein diets (- amino ACID), carnivores/omnivores
(herbivores on milk/drugs)
• Respiratory and metabolic acidosis
• hypochloremic metabolic alkalosis +sever dehydration
• Hypokalemia- body is K + deficiency, so kidney resorbs K+ and
exchanges K+ for H+(H+ put into urine)• Furosemide- blocks NaK2Cl- pump and cause increase sodium and H+ excretion
What does dipstick [protein] demonstrate?
Detects primarily albumin. insensitive to Bence jones protein,
globulins
Protienuria caused by renal dz:
blood reaction will be negative (usually), sediment will have casts. o UPCR- normal .5;
glomerular >1.0 (glomerular has highest proteinuria )
o proteinuria w/ nothing in sediment often indicative of glomerular dz
What are causes of pre renal, renal and post renal proteinuria?
Pre renal- fever, hypertension, seizures, IV
• Renal- glomerulonephritis, renal tubular injury
• Post renal- hemorrhage, infection
What are causes of a positive protein reaction on a dipstick?
• r/0 hemorrhage- positive blood reaction, will see RBC in sediment.
• r/o UTI/cystisits- will see bacteria and WBC on sediment.
• r/o intravascular hemolysis- hemoglobinuria! Hgb is a protein,
animal will be anemic.
What is specific about dogs and positive protein on a dipstick stick?
Trace to 1+ protein= normal finding in concentrated urine. Proteinuria w/ dilute urine can be a problem.
What is the sulphosalicycl acid test?
SSA used to confirm dipstick protein results- reacts adequately
w/ albumin, globulins and bence jones proteins.
• Urine supernatant + 5 % SSA! turbidity of sample compared to standards
