Equine urinary tract Flashcards
urinary tract disorders
- PU/PD
- pigmenturia
- renal disease
- neoplasia
- urolithiasis
- urinary tract infection
- developmental disorders
history taking
- abnormal urination?
- abnormal colour?
- polyuria? (increased vol)
- pollakuria? (increased freq)
- polydipsia (>100ml/kg/day)
clinical exam
- rectal to feel bladder:
- size, wall thickness, uroliths, masses
- examine penis under sedation
- pass catheter if obstruction is suspected
blood tests
haematology:
- WBC count for evidence of leukocytosis
- RBC count for evidence of anaemia
urea/creatinine:
- azotaemia
- doesn’t increase until >75% nephrons non-functional
urinalysis
- free catch sample or catheter
- no cystocentesis in horses
- USG, biochemistry (dipstick), sediment
hyposthenuria
- urine that is more dilute than serum
<1.008 - foals usually have dilute urine
isothenuria
- urine that has similar osmolarity to serum
1.008-1.014
water deprivation test
- tests for diabetes insipidus and psychogenic polydipsia
1. weigh horse
2. check urea, creatinine, USG - don’t proceed if USG >1.008
3. water removed and tests done regularly
4. stop after 24hrs, USG >1.020, azotaemia, signs of dehydration, loss of 5% BW
pigmenturia causes
- myoglobin (muscle breakdown)
- haemoglobin (RBC breakdown)
- haematuria
- start of urination (distal urethra)
- end of urination (proximal urethra)
- throughout urination (kidneys, ureters, bladder)
PU and PD causes
- renal failure
- PPID
- primary/psychogenic polydipsia
- diabetes insipidus/mellitus
acute renal failure
- associated with abrupt reduction in glomerular filtration
- leads to failure of excretion of nitrogenous waste causing azotaemia (uraemic syndrome)
pre-renal causes of acute renal failure
- decreased renal perfusion from conditions causing decreased cardiac output/increased renal vascular resistance
(dehydration, diarrhoea)
intra-renal causes of acute renal failure
- ischaemic or toxic damage to tubules
- obstruction of tubules
- acute glomerulonephritis
- inflammation)
post-renal causes of acute renal failure
- obstruction or disruption of urinary outflow tract
clinical signs of acute renal failure
- lethargy
- inappetence
- dehydration
- oliguria
diagnosis of acute renal failure
- casts in urine
- azotaemia
- imaging (ultrasound)
- biopsy?
acute renal failure treatment
- treat underlying cause
- correct fluid and electrolyte imbalances
- if insufficient response give dopamine infusion to improve renal blood flow
nursing considerations for acute renal failure
- monitor urine output, signs of oedema
- encourage appetite
- monitor complications (laminitis, thrombophlebitis)
chronic renal failure cause
glomerulonephritis (most common)
clinical signs of chronic renal failure
- present late in disease course
- lethargy (anaemia)
- anorexia
- weight loss
- PU/PD
- dental tarter
- azotaemia + inability to concentrate urine
- poor prognosis
nursing considerations for chronic renal failure
- fluid therapy to rule out acute renal failure
- access to water
- encourage eating
- reduce protein in diet (avoid alfalfa)
urinary tract infections
- not very common
- present with dysuria
- diagnose with mid-stream urine sample for bacteriology
neoplasia of the urinary tract
- uncommon other than penile tumours
- melanoma, sarcoid, papilloma
- usually squamous cell carcinoma in older geldings
penile squamous cell carcinoma
- malodourous/swollen sheath
- haematuria if distal urethra involved
- obstruction of urinary tract uncommon unless large tumours
penile squamous cell carcinoma treatment
- depends on position and extent of tumour
- local excision
- penile resection
high rate of recurrence although slow metastasis (to inguinal lymph nodes)
urolithiasis
- less common in horses than small animals
- more common in males than females (females have shorter and wider urethra)
types of urolithiasis
type 1 calcium carbonate
- >90% cases
- yellow, spiculated (spiky)
type 2 calcium carbonate
- grey, smooth
sabulous urolithiasis
- accumulation of urine sediment in ventral bladder
clinical signs of cystic calculi (bladder stones)
- dysuria (haematuria, stranguria, incontinence)
- exacerbated during/after exercise
- work up includes rectal, endoscopy, ultrasound
treatment of cystic calculi
- laparotomy and cystotomy
- recovery as for colic surgery
- impossible to dissolve stones in horses
urethral calculi
- usually in males
- small cystoliths that pass into urethra
- present with dysuria
- if blocked: colic, ARF, risk of rupture
urethral calculi treatment
- pass a catheter
- perineal urethrotomy (if repeated)
urinary incontinence
- uncommon in horses
- signs exacerbated by coughing/exercise
- signs similar to urolithiasis which is more common
causes of urinary incontinence
- upper motor neuron (equine herpes virus), lower motor neuron, myogenic disorders
- sabulous urolithiasis
bladder paralysis
- feature of neurological diseases
- urinary incontinence, urine scalding, loss of anal/tail muscle tone
nursing considerations for urinary incontinence and bladder paralysis
- cleaning of perineum/hindlimbs
- protection from urine scalding
- management of urinary catheter (if necessary)
- monitor urine output, urine
urinary tract conditions in foals
- patent urachus
- ruptured bladder
patent urachus
- in foetus urine passes from bladder to allantoic cavity via urachus
- normally urachus closes at parturition
- patent urachus is failure of closure
- will see urine drip from umbilicus
- usually close over time but prophylactic antibiotics may be considered
- surgical correction if persists
bladder rupture in foals
- occurs during parturition, usually in males
- progressive dullness over first 72hrs
- results in hyperkalaemia, uroabdomen
- surgical correction after fluid therapy
