Urinary Flashcards
Normal equine urine output
50-60 ml/kg/day
Measures for poor kidney function
Leukocytosis
Anaemia due to reduced erythropoietin production in kidneys
Inflammatory markers
Azotemia
Bun: creatinine alterations (<10:1 with ARF, >15:1 with CRF)
Electrolytes
Protein
Albumin
Muscle enzymes
Glucose
Is serum BUN or serum creatinine more sensitive for decrease in GFR
Serum creatinine
What happens to USG in prerenal azotemia
Increases - hypersthenuric
Do horses with intrinsic renal azotemia develop hyposthenuria
No as kidney cannot actively dilute urine
What can the BUN: creatinine be reliably used to differentiate
Prerenal from renal azotemia
Hypercalcemia and hypophosphatemia are most commonly seen with which kidney disease
Chronic renal failure
What value is hyposthenuria
<1.008
What values are isosthenuric
1.008-1.014
What values are hypersthenuric
> 1.014
What is the normal usg range for a horse
1.025-1.045
Why can you get false + protein on reagent strips
Equine urine is alkaline and strips are made for acidic urine
What is the most common thing to see n sediment exam
Dicalcium phosphate
How should you measure water intake in the horse
Turn off automatic waterers, keep on own, measure volumes drank across 3-5 24h periods and take average
What are causes of myoglobinuria
Exertional rhabdomyolysis
Post anaesthetic myopathy
Atypical myopathy
Immune mediated myopathies
Nutritional myopathies
Toxic myopathies
What are causes of hemoglobinuria
Equine infectious anaemia
Immune mediated
Toxins (red maple leaf, copper, wild onion)
What are causes of haematuria
Exercised induced
Urolithiasis
UTI/pyelonephritis
Idiopathic renal haematuria
Idiopathic haemorrhagic cystitis
Urethral rents
Neoplasia
Treatment for haemaglobinuria
Treat primary disease
+/- IV fluids
Treatment for UTI/pyelonephritis
Antimicrobials
Treatment for idiopathic renal haematuria
Supportive care+/- blood transfusion
Treatment for idiopathic hemorrhagic cystitis
Nsaids
TMPS
Treatment for urethral rents
Benign neglect
If causing anaemia or not resolving then surgery
Treatment for renal neoplasia
Unilateral nephrectomy or surgical removal/chemotherapy dependent on location
Overall best diagnostics for urinary disease
History and endoscopy
Signalment more prone to urolithiasis
Geldings due to long urethra
Diagnosis of cystic calculi of the bladder
Rectal palpation
Cystoscopy
Rectal ultrasound
Treatment of cystic calculi of the bladder
Surgery/lithotripsy
Manual removal of those under 10cm in the mare
Clinical signs of cystic calculi of the bladder
Dysuria
Stranguria
Pollakiuria
Haematuria
Clinical signs of urethral calculi
Acute obstruction
Colic.
Posturing
Anuria
Blood at orifice
Diagnosis of urethral calculi
Urethroscopy
Pass urinary catheter
Abdominocentesis for bladder rupture
Treatment of urethral calculi
If upper - perineal urethrotomy
Lower - transendoscopic or surgical retrieval
Clinical signs of nephroliths
Often none
Sometimes colic
Intermittent or persistent haematuria
Diagnosis of nephroliths
Often incidental at PM
Plasma biochemistry for CRF if bilateral
Pigmenturia
Treatment for nephroliths
Surgery +/- lithotripsy
What does a red/brown pigmenturia with clear supernatant at the beginning of urination indicate
Haematuria from distal urethra
What does a red/brown pigmenturia with clear supernatant throughout urination indicate
Kidney/ureter/bladder haematuria
What does a red/brown pigmenturia with clear supernatant at the end of urination indicate
Bladder/proximal urethral haematuria
What does brown/red urine, discoloured after centrifuging with pink serum colour indicate?
Haemaglobinuria
What does brown/red urine, discoloured after centrifuging with normal serum colour and increased CK indicate?
Myoglobinuria
What does orange urine, haem -, bilirubin+ indicate
Liver disease
What does orange urine, haem -, bilirubin - indicate
Drugs eg rifampin
What is CKD
Chronic, irreversible damage of the kidneys over 3 months in duration
What is the pathogenesis for CKD
Acute kidney injury
Maladaptive repair
Progressive scarring
What are the two pathways acute kidney injury can take
Adaptive repair to resolution
Or
Maladaptive repair to progressive scarring
Clinical signs of primary tubulointerstitial disease
Weightloss, pupd, central oedema
Pathology associated with primary tubulointerstitial disease
History/clinical signs
Increased creatinine and hypercalcemia
Urinalysis - usg 1.009-1.014 and cytology of casts, tubular casts, neoplastic cells and leukocytes
Dipstick or proteinuria
What can transabdominal ultrasound of kidneys show
Nephroliths
Kidney size
What is best to do when requiring a kidney biopsy
Refer it
What does primary glomerular disease show
Glomerular nephritis
Immune complex deposition
How to manage CKD
Avoid toxic insults
Plenty of fresh water
Dietary management (low carb, low salt, balanced protein)
Definition of polydipsia
Water consumption over 70-100ml/kg/day
Affects on normal water intake
Temperature
Humidity
Level of exercise
Lactation
Normal urine production
15-30ml/kg/day
Define polyuria
> 50ml/kg/day
Physiological causes of PUPD
Excessive protein consumption
Excessive salt consumption
Drugs eg glucocorticoids, furosemide, a-2 agonists
Pathological causes of PUPD
Apparent psychogenic polydipsia
PPID
Chronic renal failure
Hepatic insufficiency
Sepsis/endotoxaemia
Renal medullary washout
Diabetes mellitus/insipidus
How do you diagnose APP
Through exclusion
Why does app occur
Boredom when stabled leading to polydipsia
Management of APP
Restrict salt intake
Restrict water intake
Clinical signs of PPID
Pupd in 76% of cases
Long curly coat
Weight loss/muscle wastage
Potbelly
Regional adiposity
Laminitis
Etc
Difference between neurogenic and nephrogenic DI
Neurogenic - inadequate ADH secretion
Nephrogenic - decreased sensitivity to circulating ADH
Difference between type 1 and type 2 DM
Type 1 - insulin dependent - lack of production
Type 2 - insulin independent - high insulin but tissues insensitive
Causes of iatrogenic pupd
IV fluids
Diuretics
Corticosteroid therapy
Sedation with a2
Excessive dietary salt
How does the water deprivation test differentiate app from di
App will concentrate urine
DI will not
What is the modified water deprivation test
Allow water consumption of 40ml/kg/day in spread out amounts
Measure serum urea, creatinine and usg every 6 hours
Continue for 2-3 days
USG>1.020 = APP
Serum ADH change after WDT
Normal is 1-2pg/ml
After 24h WD should increase to 4-8pg/ml
Failure to increase shows central DI
ADH response test
Differentiates central and nephrogenic DI
Central concentrates urine after exogenous ADH
Nephrogenic has little or no response
When is AKI common
In hospitalized horses
Definition of ARF
Advanced decline in GFR over days to hours
Clinical signs and pathology associated with this
Causes of ARF
Haemodynamic
Nephrotoxic
Uncommon
- interstitial nephritis
- obstructive nephropathy
Rare
- acute glomerulopathies
Predisposing diseases to ARF
D+
SIRS/mods
Myopathies
Clinical signs of ARF
Predisposing disease
Colic
Fever
Urine output
Clinical pathology of ARF
History, clinical signs and lab findings
Increased creatinine
USG - 1.008-1.016
Urine dipstick
- proteinuria
- haeme
Serum electrolytes
- hyponatremia
- hypochloremia
- variable potassium
What are renal biopsies useful for
Learning aetiology
Prognosticator
Treatment for ARF
Cease nephrotoxic drugs
Manage primary disease
IVFT
Prognosis for ARF
Haemodynamic - if primary disease in treated and perfusion improves
Nephrotoxic - dependent on urine output and improved serum creatinine
Oliguric and anuric - poor to guarded, increased if converted to polyuria
