9/13/2023
Hematuria and Pigmenturia
in the Horse
Mariano Mora-Pereira DVM, MS, PhD, DACVIM-LA
Hematuria and Pigmenturia
• Hematuria: Blood in the urine
• Pigmenturia: Presence of a component that gives an abnormal color
to urine
• Color of urine associated with excretion of urochrome
• Product of the degradation of hemoglobin
Urine collection
• Free catch
• Catheterization
• Endoscopy
• Ureter
1
9/13/2023
Hematuria
Hematuria
Origin of blood
a) Kidney
b) Bladder
c) Ureter
d) Urethra
e) Reproductive tract
Hematuria
• Macroscopic or microscopic
• Severe cases voiding of blood clots
History
• Drugs administered
• Type of pasture
• Geographical location
• Recent exercise, abnormal gait
2
9/13/2023
Hematuria
• Timing of micturition
• Beginning to end renal, ureteral or bladder
• End proximal urethra or bladder neck
• Beginning distal urethra
Exercise-induced hematuria
• First void after exercise
a) Cystoliths
b) Bladder trauma against pelvic rim (Concussion)
c) Osteochondroma of the os pubis
Hematuria caused by osteochondroma of the os pubis. EVE 24:30-37, 2012
Urolithiasis
• More often in males
• Hematuria after exercise
• Near the end of urination
• Pollakiuria Image courtesy Dr. Lindsey Boone
• Dysuria
• Dribbling urine
• Prolonged periods of penile protrusion
• Blood-stained pelvic limbs
3
9/13/2023
Urolithiasis
Nephroliths and ureteroliths
• Partial or complete obstruction
• If bilateral chronic renal failure
• Mild recurrent colic
• Microscopic hematuria
Saetra, T., et al. (2018). Equine Vet Educ, 30: 635-639.
Urolithiasis
Diagnosis
• Rectal palpation
• Ultrasound
• Cystoscopy
• Type 1- yellow to green, spiculated, friable
(mainly CaCO3)
• 90% cases
• Type 2- Smooth, hard and white
(CaCO3+phosphate+Mg)
Image courtesy Dr. Lindsey Boone
Urolithiasis
Cystolith Nephrolith
4
9/13/2023
Cystoscopy
Video courtesy Dr. Erin Groover Image courtesy Dr. Lindsey Boone
Urolithiasis - treatment
• Surgical/manual removal
• Laser and shock wave
• Recurrence
• 46.6%
• Fragments acting as a nidus remained
• Undetected calculi
• Propensity toward stone formation (Ca crystal aggregation)
Image courtesy Dr. Lindsey Boone
Urolithiasis - treatment
• No studies to prove that urine acidification prevents formation
• Below pH 6.5 calcium carbonate uroliths do not form
• Prevented new calculi formation in a single case of a horse with recurrent
cystic calculi
Remillard et al. 1984
5
9/13/2023
Sabulous cystitis
• Secondary to ventral accumulation of urine sediment
• Associated with bladder dysfunction
• Urinary incontinence
• Most common presenting complain
• Treatment
• Bladder lavage
• Antimicrobials
• Anti-inflammatories
• Bethanechol Zakia et al. 2022. JVIM
• Phenazopyridine
Urinary tract infection and pyelonephritis
• Primary (rare)
• Secondary
• Paresis or paralysis of the bladder
• Urocystoliths
• Urinalysis
• ↑ WBCs
• Intracellular bacteria
• Quantitative urine culture
(>10,000 CFU/mL)
Urinary tract infection and pyelonephritis
• Lower urinary tract Bladder, urethra
• Multiparous mares
• Chronic atonic bladders
• Upper urinary tract kidneys, ureters
• Pyelonephritis renal pelvis and parenchyma
• Associated with nephroliths or ureteroliths
• Microscopic or macroscopic hematuria
• Unilateral or bilateral renal hemorrhage
Linton, 2022
6
9/13/2023
Clinical case
• 12 YO AQH gelding
• Acute hematuria of 3-day duration
• Lethargic 2 weeks prior
• HR 48 bpm, RR 16 brpm, T 100.2F
• Hematuria (frank blood) in the mid-late stream
Clinical case
Clinical case
• Diagnosis based on ultrasonographic findings
• ↑ renal echogenicity
• Abnormal outline
• ↓ corticomedullary distinction
• Debris in the renal pelvis
• Dilated renal pelvis (pyelectasia)
• Renal biopsy?
7
9/13/2023
Jocelyn N. Kidney disease in the horse. Equine Health. 2020;2020:20-23.
Habershon-Butcher, J., Bowen, M. and Hallowell, G. (2014), VALIDATION OF A NOVEL TRANSLUMBAR ULTRASOUND TECHNIQUE FOR MEASURING RENAL DIMENSIONS IN HORSES. Vet Radiol
Ultrasound, 55: 323-330.
Clinical case
• Unilateral kidney hemorrhage
• Collection of samples for urinalysis, bacterial culture, leptospirosis
Clinical case
• IV fluid therapy
• Enrofloxacin IV
• Bacterial culture – No bacterial growth
• Idiopathic renal hematuria?
• Necropsy
• Bilateral chronic interstitial nephritis and
pyelonephritis
8
9/13/2023
Treatment
• Antibiotic based on culture and sensitivity
• Use an antibiotic eliminated in urine
• Penicillin (unchanged)
• Aminoglycosides (unchanged) (nephrotoxic)
• TMS (mostly—some through the liver)
Neoplasia
• Clinical signs similar to those of horses with
cystic calculi
• Rectal palpation
• Mass in bladder
• Enlarged kidney
• Ultrasound
• Cystoscopy
• Urinalysis and cytology Wise et al. 2009. JVIM
• Nephrectomy search for metastasis first
Verminous nephritis
• Halocephalobus gingivalis
• 1. Brain (mimics EPM)
• 2. Spinal cord
• 3. kidney
• Renal granulomas
• Diagnosis
• Renal ultrasound
• Nematode in urine sediment
• Treatment
• Larvicidal antihelmintic
• No successful medical treatment reported
• Nephrectomy
9
9/13/2023
Clinical case
• 13 YO AQH gelding
• Intermittent hematuria of 1 month duration, fever
• Evaluated few weeks prior unknown origin of hematuria
Physical exam
• HR 74 bpm, RR 20 brpm, T 104.4F
• CRT 3.5 s
• Yellow/cloudy urine with blood at end of urination
• Sabulous material on hind limbs
Clinical case
• Abdominal ultrasound Normal kidneys, slightly hypomotile SI
• Rectal enlarged bladder, normal left kidney
• Abdominocentesis pale yellow, clear
• Normal coagulation profile
• Urinalysis by catheterization
• CBC and chem
Clinical case
10
9/13/2023
Clinical case
• Treatment with TMS 25 mg/kg q12h
• Flunixin meglumine 1.1 mg/kg q12h
Clinical case
• Cystoscopy
Clinical case
11
9/13/2023
Urethral rents
• Linear defect of the urethral mucosa
• Convex surface of the urethra at the level of the ischial arch
• Communicate with the corpus spongiosum penis (CSP)
• Bulbospongiosus muscle contracts to expel urine from the urethra at
the end of urination
• Increase in pressure within the CSP
Urethral rents
• Terminal hematuria in geldings
• Hemospermia in stallions
• Baseline pressure within the CSP was not significantly different
between geldings and stallions
• Peak urination pressure within the CSP of geldings was significantly
increased when compared to stallions (25 vs 14.5 mmHg)
Taintor et al. EVJ. 2004
Urethral rents
Diagnosis
• Timing of hematuria
• Urinalysis might be normal if caught at the beginning
• +/- mild anemia
Treatment
• Often self resolves
• Perineal urethrotomy or corpus spongiotomy
12
9/13/2023
Pigmenturia
Hemoglobinuria
• Intravascular hemolysis RBCs release hemoglobin
• Pink/red serum
• Signs of primary disease
• Sample not clear after centrifugation
Clinical case
• 16 YO AQH mare
• 2-day history of lethargy
• Anemia and urine discoloration
• HR 60 bpm, RR 20 brpm, T 98.8F
• MM: dry, cyanotic, CRT 2 sec
• Dark urine
• Remained dark after centrifugation
Images courtesy Dr. Lascola and Dr. Ceriotti
13
9/13/2023
Clinical case
Clinical case
Caza T. AJKD. 2022
Red maple toxicosis
• Anemia caused by oxidative damage to the
erythrocyte cell membrane and hemoglobin
• Summer-fall
• ~60% fatality rate
• Signs observed 12-48 hrs
• Renal failure secondary to hemoglobin
deposition in the kidney
14
9/13/2023
Red maple toxicosis
Management
• Prevent toxic absorption activated charcoal 1-3 g/kg BW
• Nasal oxygen
• Blood transfusion
• IV fluids
• Judicious use of NSAIDs
• Avoid corticosteroids and DMSO
Hemoglobinuria
Common causes of intravascular hemolysis
• Parasitic – piroplasmosis Toxins
• Viral – EIA Red maple leaf*
• Bacterial – C. perfringens type A Phenothiazine
• Immune mediated Copper
Wild onion
Wise et al., 2013. JVIM
Myoglobinuria
• Secondary to severe muscle injury
• Exertional rhabdomyolysis
• Leakage of myoglobin from myocytes
• Brown-to-red discolored urine
• Clinical signs of rhabdomyolysis
• Urine discolored after centrifugation
15
9/13/2023
Myoglobinuria
• CK > 2,000 IU
• Serum will be clear
• Myoglobin has no carrier protein rapidly cleared
• Hemoglobin is bound to haptoglobin not rapidly cleared
Myoglobinuria
Seasonal pasture/Atypical myopathy
• Non-exertional rhabdomyolisis
• Ingestion of hypoglycin A disruption of mitochondrial fatty acid
metabolism in myocyte
• HGA in seeds of Acer tree
• Onset 12-24 hrs after ingestion
• > fall
Drugs
• Doxycycline → dark brown or black-colored urine
• Rifampin → red- or orange-colored urine
• Phenazopyridine → red- or orange-colored urine
Plant pigments
• Red clovers porphyrins red urine
• Alsike clover brown urine
16
9/13/2023
Urinalysis
• Hemorrhage more than 5-8 RBCs
• Differentiate between hematuria, hemoglobinuria or myoglobinuria
• False results diluted (<1.006), pH > 8, delayed analysis
• RBC lysis
Urine RBCs
Hematuria Clear Precipitated
Hemoglobinuria Red
Myoglobinuria Red
Differentiating hemo- and myoglobinuria
• Ammonium sulfate precipitation
• Hemoglobin precipitates at 80% saturation
• Myoglobin precipitates at full saturation
• Electrophoresis
• Spectroscopy
• Biochemical results
• Hemoglobinuria intravascular hemolysis Pink serum
• Discoloration with negative strip plant or drug pigmenturia
Summary
• Thorough clinical examination
• Systemic disease
• Need for blood transfusion
• Differentiate hematuria, hemoglobinuria and myoglobinuria
• History, bloodwork, serum color, urine color, ultrasound, etc
• Direct treatment and prognosis
• Acknowledge the risk for renal failure
17
9/13/2023
Questions
18
