VetLab (cm;para)

• Purpose of Urinalysis


  • used to diagnose disease, screen asymptomatic populations for undetected disorders (or metabolic disorders), progress of the disease and effectiveness of the therapy
• Urinalysis


  • One of the common procedure that is performed in the laboratory
  • Known to be reliable, accurate, safe and most importantly cost effective so it is usually requested as one of the procedures that are performed in the laboratory
• Urinalysis Sample Collection


  1. Free catch (voided sample)
  2. Bladder expression
  3. Catheterization
  4. Cystocentesis
• Free Catch (Voided Sample)


  • Similar to midstream clean catch in humans
  • Easiest to collect, usually brought by the owner
  • The owner is instructed on proper collection to maintain quality control
  • First morning, midstream is preferred for a good sample
  • For cats: use non-absorbent litter and a collection cup or ladle
  • For dogs: use a shallow dish
• Sample Collection Tips


  • Ensure no contaminants are in the collection container
  • Use a leak-proof container with a well-fitting, clean lid, free of any previous contents or detergents
• Bladder Expression


  • Position the animal standing or in lateral recumbency and palpate the bladder
  • Once located, apply gentle, steady pressure until the animal begins to urinate
  • Do not apply excessive pressure, as it can rupture the bladder, making the sample unreliable
  • Avoid bladder expression if the animal has a suspected fragile or obstructed bladder due to increased risk of rupture
• Catheterization


  • A rubber catheter is inserted into the urethra up to the bladder to collect a sample
  • A sterile syringe is attached to the catheter to withdraw urine
  • Method depends on the species and sex of the animal
  • Requires a sterile catheter, lubricant, and sterile gloves to prevent infection
  • For female patients, a speculum is used for easier visualization of the urethral opening
  • Samples collected by this method are sterile and suitable for bacterial culture
• Cystocentesis


  • Similar to suprapubic aspiration in humans
  • Suitable for calm, easily restrained animals (may require sedation)
  • Place the animal in dorsal recumbency and palpate the bladder; use ultrasound if palpation is difficult
  • Typically uses a 22- to 25-gauge needle inserted through the abdominal wall into the bladder
  • Do not redirect the needle after insertion to avoid damaging adjacent organs
  • Release the syringe's negative pressure before removing the needle
• Cystocentesis Needle Insertion


  • Female dogs and cats: along the midline of the caudal abdomen
  • Male dogs and cats: caudal to the umbilicus
• Free catch Advantages

  • No risk/complication
  • Easiest to collect

  Free catch Disadvantages

  • Contamination
  • Unsuitable for bacterial culture
• Bladder expression Advantages

  • Can be performed anytime

  Bladder expression Disadvantages

  • Trauma
  • Unsuitable for culture
  • Not recommended for specimen with suspected obstruction or fragile bladders
• Catheterization Advantages

  • Collected in sterile Manner
  • Possible to collect urine sample even with low volume of bladder
  • Appropriate for bacterial culture

  Catheterization Disadvantages

  • Difficult to perform in female Animals
  • Increase Trauma/ Iatrogenic infection
• Cystocentesis Advantages

  • Sterile
  • Appropriate for bacterial culture
  • Aseptic technique (75% alcohol and followed by povidone iodine or 70% alcohol most of the time. It will depend on the protocol of the institution)
  • Low risk of causing infection (iatrogenic infection)
  • No contamination of urine

  Cystocentesis Disadvantages

  • Sedation may be required
  • Can be performed for restrained animals
  • Expensive
  • Requires adequate volume of urine within the bladder and possible having microscopic
  • hematuria
• Sample Preservatives

  1. Refrigeration
  2. Freezing
  3. Toluene
  4. Formalin (40%)
  5. Boric acid (0.8%)
  6. Commercial preservation tablets
• How soon must urinalysis be performed after sample collection in animals vs. humans

  • Animals: within 20 minutes
  • Humans: within 2 hours
• Refrigeration


  • It is common for up to 6 hours
  • Allow sample to return to room temperature before analysis to avoid false chemical readings and high crystal formation due to low temperatures
  • Advantages:
  • Doesn’t interfere with chemical tests.
  • Disadvantages:
  • Can precipitate amorphous substances and raise specific gravity
• Freezing


  • Advantages:
  • Inhibits bacterial growth
  • Doesn’t interfere with chemical tests
  • Suitable for most chemical tests and preserves mineral content
  • Disadvantages:
  • Not suitable for sediment preservation and hormonal analysis
  • Causes cellular and protein damage
• Toluene


  • organic solvent
  • Advantages:
  • Doesn’t interfere with routine tests
  • Prevents loss of acetone
  • Suitable for chemical analysis
  • Disadvantages:
  • Floats on the specimen's surface
  • Cannot prevent bacterial growth
• Formalin (40%)


  • Reducing agent
  • Can prevent microbial growth
  • Advantages:
  • Excellent sediment preservative
  • Disadvantages:
  • Interfere with chemical analysis
  • Can cause false negative results
• Boric acid (0.8%)


  • Can also inhibit the growth of bacteria
  • Exception of Ph and chemical analysis
  • Advantages:
  • Preserves protein and formed elements
  • Appropriate for sediment analysis
  • Disadvantages:
  • Precipitation of crystals
• Common preservation tablets


  • Effective for up to 5 days
  • Advantages:
  • Controls pH
  • Inhibits microbial growth
  • Provides good preservation of sediment (leukocytes, erythrocytes, casts, crystals)
• Sodium Fluoride


  • Prevents glycolysis
  • Used for drug analysis
• Phenol


  • Does not interfere with routine tests
  • May change the odor of urine
• Physical Examination


  • Volume
  • Color
  • Odor
  • Turbidity
  • Specific gravity
• Volume


  • Depends on hydration status and renal concentrating abilities of patient
  • inversely related to specific gravity
  • Few urine volume = high specific gravity
  • high urine volume = low specific gravity
  • Polyuria - increase amount of urine
  • Oliguria - decrease amount of urine
  • Anuria - no urine is produced
  • Normal daily urine output: 1 mL/kg/h
• Color


  • Straw - normal
  • Colorless-pale - diluted urine
  • Deep Yellow - due to concentrated urine (normal) or bilirubinuria (with condition)
  • Orange-red - hematuria or hemoglobinuria
  • Red-brown - myoglobinuria
  • Milky white - pyuria (increase WBC)
• Odor


  • Usually not assess odor
  • Strong odor
  • from pheromones, especially in cats and goats during mating season
  • Ammonia
  • Indicates cystitis or urinary tract issues
  • Putrid
  • Sign of protein degradation, often due to infection
  • Fruity
  • Indicates increased ketones, common in ketosis
• Turbidity


  • Cloudiness indicates high cellular elements, crystals, microorganisms, or mucus
  • Increase turbidity: More cellular elements, crystals, or microbes present
  • Before checking turbidity: Mix specimen properly and bring to room temperature
• Turbidity scale


  • Clear (0)
  • Slightly cloudy (1)
  • Cloudy (2)
  • Turbid (3)
• Specific gravity 


  • Important step in urinalysis and it indicates kidney concentration ability
  • Specific Gravity Range: Normal: 1.015 - 1.045 (up to 1.067 in cats)
  • Dipstick test: May be inaccurate in animals due to higher specific gravity limits
  • Calibration: Refractometer must read water as 1.000; calibrate regularly
  • Measurement Technique: Mix equal parts urine and distilled water; multiply last two digits of the reading by 2
• Hypersthenuria


  • higher than glomerular filtrate
  • dogs: >1.030
  • cats: >1.035
• Hyposthenuria


  • lower than glomerular filtrate
  • <1.008
• Isosthenuria


  • 1.008 - 1.012
• Chemical Examination


  1. Reagent strip
  2. Microscopic/sediment examination
• Reagent strip


  • Simple, rapid means for performing medically significant chemical analysis of urine
  • Chemically impregnated absorbent pads attached to the plastic strip
  • 4 parameters: glucose (30), protein (45), specific gravity (60), pH (60)
  • Other parameters:
  • Ketones (40)
  • Blood (45)
  • Nitrite (60)
  • Bilirubin (60)
  • Urobilinogen (60)
  • Leukocytes (120)
  • 11th parameter - ascorbic acid
  • 12th parameter - microalbumin/creatinine
• Urinary casts


  • Hyaline
  • Epithelial
  • Granular
• Urinary Crystals


  • Ammonium urate
  • Amorphous urates (acidic); Amorphous phosphates (basic)
  • Bilirubin
  • Calcium carbonate
  • Calcium oxalate (dihydrate)
  • Calcium oxalate (monohydrate)
  • Cholesterol
  • Cystine
• Sample collection in Parasitology


  • A minimum of 10 grams of fresh feces should be collected
• Pooled fecal samples


  • describe a collection of fecal samples obtained from a group of animals that are housed together
• Gross/Physical Examination


  • Consistency
  • Color
  • Blood
  • Mucous
  • Gross parasites