approach to eq urinary

Presenting signs

·    Quiet

·    Inappetent

·    Change in urine output

Investigations

·    History and clinical exam

o  On any medications?

o  Any other clinical signs, e.g. D+

o  Exercise intolerance/poor performance?

o  Any other animals affected?

o  Any recent surgery?

o  Can they measure water intake/urine output?

o  Recent management/dietary changes?

·    Haematology – TP to assess hydration status, low albumin = PLN

·    Biochemistry – azotaemia? Ca level usually increased 

·    Urine sample

o  USG – see if pre/post/renal azotaemia

o  Urine dipstick – high pH = ARF, high protein = PLN

·    Abdominal U/S to see kidneys

o  Enlarged kidneys, painful, perirenal oedema = ARF

o  Small and hard = CRF

o  Increased corticomedullary definition = papillary necrosis due to NSAIDs

·    Renal biopsy if unsure of aetiology, guides prognosis

General management

·    IVFT

·    Diet – balanced protein, low salt, low carb

·    Increase water intake – add molasses

·    Stop NSAIDs, oxytet, gentamicin

·    Re-check USG and renal parameters

ARF vs CKD

ARF

CKD

Presenting signs

·    Colic signs

·    Changes to urine output

·    Pyrexic

·    Signs of pre-disposing disease, e.g. D+, SIRS/MODS, myopathies

·    Weight loss, reduced appetite

·    PUPD

·    Ventral oedema

·    Dull hair coat

Diagnosis

·    Increased creatinine

·    Isosthenuric USG

·    Proteinuria, haemturia

·    Enlarged kidneys on U/S

·    Low calcium, high phosphorus

·    Increased creatinine

·    Isosthenuric USG

·    Proteinuria

·    Hypoalbuminaemia

·    Anaemia

·    Small kidneys on U/S

·    Biopsy

·    High calcium, low phosphorus

Treatment

·    Stop nephrotoxic drugs

·    Treat primary cause

·    IVFT Hartmann’s 2x maintenance

·    If glomerulonephritis – steroids and abx

·    Avoid NSAIDs

·    Encourage drinking and diuresis – add molasses to water, provide salt lick

o  IVT not required

PUPD

·    PD >100ml/kg/day (normal water intake = 50ml/kg/day)

·    PU >50ml/kg/day (normal urine output = 20ml/kg/day)

Causes:

·    Physiological: lactating mares, working hard, high environmental temperature, excessive dietary protein, excessive salt consumption, drug administration (GCCs, diuretics)

·    Pathological: apparent psychogenic PD, PPID, CRF, hepatic insufficieny, renal medullary solute washout, sepsis/endotoxemia, DM, DI

o  APP = most common cause, due to change in diet, stabling, management, environment

§ Diagnosis: exclusion of other causes (no azotaemia

§ Treatment: restrict salt and water intake

·    Iatrogenic: IVFT, diuretics, CS administration, alpha-2s used for sedation, excessive salt in diet

History

·    Timing of pigmenturia

o  Beginning of urination = issue with distal urethra

o  Throughout urination = kidney, ureter or bladder problem

o  End of urination = issue with bladder or proximal ureter

·    Any other clinical signs, e.g. signs of infection, myopathies

Investigation

·    Clinical exam

·    Dipstick urine – is it haem positive or negative

o  If haem positive ® centrifuge

§ Clear = haematuria

§ If discoloured ® look at serum colour

·    Pink = haemoglobinuria

·    Normal ® look at CK ® if increased = myoglobinuria

o  If haem negative ® dipstick for bilirubin

§ Bilirubin positive = liver disease

§ Bilirubin negative = drugs

·    Haematology

o  TP/PCV – assess hydration state – differentiate between acute/chronic problem

o  Increased WBC/SAA = infectious/inflammation

o  Anaemia = EIA

·    Biochemistry

o  Evidence of azotaemia – tells us about kidney function

·    U/S bladder – looking for uroliths

·    Cystoscopy to directly visualise the bladder

Management

·    Myoglobinuria

o  IVFT as build up is nephrotoxic

o  Analgesia

o  Treat underlying cause

·    Haemoglobinuria

o  Treat underlying/primary disease

o  IVFT if concern for kidneys

·    Haematuria – treat underlying cause

o  Urolithiasis – remove

o  UTI, pyelonephritis – C+S for abx

o  Idiopathic renal haemorrhage – NSAIDs and TMPS

o  Urethral rents, neoplasia – surgery

Causes

·    Haematuria

o  Exercise induced

o  Urolithiasis

o  UTI/cystitis

o  Pyelonephritis

o  Idiopathic renal haemorrhage

o  Urethral rents

o  Neoplasia

·    Myoglobinuria

o  Rhabdomyolysis due to muscle injury (myoglobin can leak into plasma)

§ Exertional rhabdomyolysis

§ Atypical myopathy

§ Toxic

§ Nutritional

§ Immune-mediated

·    Haemoglobinuria

o  Due to ongoing IV haemolysis – due to EIA, immune-mediated, toxins (copper)