LA Urinary tract diseases Flashcards
Outline urolithiasis in farm animals
- leading cause of obstruction
- v common in small ruminants d/t dietary imbalances
- males and females develop uroliths, generally only males show signs of urinary obstruction
Predisposing factors - farm animal urolithiasis
> Castrated males • Diet has major influence – high concentrate / low roughage – high phosphate diets/low calcium diet – high magnesium diets – alkaline urine • Dehydration • Urinary tract infection
Types of farm animal uroliths
DIET DEPENDENT:
- calcium (apatite and carbonate)
- phosphate (calcium and magnesium ammonium = struvite types)
- silicate
- oxalate
Site of urolithiasis obstruction - cattle and small ruminants
- CATTLE: distal sigmoid flexure
- SMALL RUMINANTS: urethral (vermiform) process in small ruminants > distal sigmoid flexure
CS - farm animal urolithiasis
• Early clinical signs – haematuria, dysuria, crystals on prepuce – urine dribbling – tail flagging & colic signs • Later clinical signs – anorexia, depression – preputial swelling – abdominal distension – recumbent, seizures and death
Dx - farm animal urolithiasis
- hx and CS
- axotaemia, hyperkalaemia, hyponatraemia, acidosis
- ultrasound
- radiograph
Complications - farm animal urolithiasis
• bladder rupture – painful becoming comfortable then sick – abdominal distension and uroperitoneum • urethral rupture – swollen prepuce • hydronephrosis – requires chronic obstruction – diagnosis via ultrasonography
Managemetn - farm animal urolithiasis
• Medical management – increase diet Ca: P ratio – urinary acidification • Surgical management – urethral process amputation – perineal urethrostomy – tube cystotomy
How common is amyloidosis in cattle? what is it associated with>
- common in cattle
- assoc with chronic sepsis (metritis, mastitis, pneumonia, pericarditis)
Outline amyloidosis in catlle
- inflammation drives SAA production –> glomerulopathy
- loss of glomerular function –> PLN
- oedema, wt loss, chronic diarrhoea
- proteinuria, hypoalbuminaemia, azotaemia
- raised serum fibrinogen, SAA, globulins
Tx - cattle amyloidosos
None
Outline enzootic haematuria in cattle
- cattle and sheep grazing bracken
- requires chronic (>12 months exposure)
- multiple cases
- contains ptaquiloside carcinogens
- bladder wall neoplasia (haemorrhagic cystitis, haematuria)
- anaemia
- differentiate from haemoglobinuria
Ddx - enzootic haematuria
haemoglobinuria
Proper name for ‘pizzle rot’
= ulcerative posthitis/ vulvitis
Outline pizzle rot in small ruminants
- ulcerative bacterial infection of prepuce and vulva MM (C. renale, high protein diets seem to predispose)
CS - pizzle rot
- pain
- loss of condition
- decreased fertility/ libido
Management - pizzle rot
- penicillin
- NSAIDs
- reduce dietary protein
Outline pyelonephritis in FA and horses
- ascending (usually) infection of urinary tract
- commonest renal dz in cattle
- post-parturition and post service/ covering
- following metritis and urolithiasis
Acute PN CS
– pyrexia, anorexia, depression, colic signs
– decreased milk yield
– stranguria, polyuria, hematuria, pyuria
Chronic PN CS
weight loss, colic, decreased milk yield, diarrhoea, polyuria,
anemia, less obvious signs of urinary tract infection
Which bacteria cause PN in cattle?
- mainly GRAM NEGATIVE (coliforms, Proteus sp, Klebsiella sp, Enterobacter sp)
- also GRAM POSITIVE: (A.pyogenes, rarely C. renale)
Dx - bovine PN
– clinical signs and rectal palpation
– pyuria, haematuria, proteinuria
– azotaemia
– urine culture?
Tx - bovine PN
– long term (14-21 days) broad spectrum AB’s
– oxytetracycline or penicillin/aminoglycosides
How can infection establish in umbilicus?
- umbilicus as portal of entry
- localise following haematogenous spread from GIT, other sites of sepsis or generalised septicaemia
What part of umbillicus tends to be most commonly infected?
arteries and urachus > vein
Common umbilical pathogens
- E. coli, Actinobacillus equuli, Klebsiella spp, Pseudomonas spp
- Bacillus spp, S. aureus, Strep spp, Enterococcus spp
- Clostridium spp
- mixed infections common
CS - umbilical pathogens
- fever, malaise, lethargy
- heat, pain, swelling and discharge from umbilicus
- localising signs aren’t present in every case, particularly when there is generalised septicaemia
Why is ultrasound useful for diagnosis of umbilical infection?
- enlargement of BVs (normal A and V
Tx - umbilical infection
- SURGICAL RESECTION: presents spread to other sites, animals with generalised septicaemia may not be good candidates for anaesthesia
- BS AB Tx: monitor response with ultrasound, if umbilicus continues to enlarge, change AB or consider sx
ABs for umbilical infection
- CEFTIOFUR: in foals require 2x adult horse dose
- TRIMETHOPRIM-SULPHONAMIDE: economical and given orally but organisms may not be sensitive
- AMINOGLYCOSDIES: care in v young animals (nephrotoxic), used in conjunction with gram positive cover
- PENICILLINS and other BETA-LACTAMS
- CEPHALOSPORINS
Ddx - umbilical infection
umbilical hernia
Outline umbilical hernia
- small hernias
Differentiate patent and persistent urachus
- PATENT: has been closed then opens d/t infection or prolonged recumbency
- PERSISTENT: open since birth, excessive torsion in parturition? may need cautery or sx resection
Outline renal failure in horses
- primary renal failure less common than renal failure secondary to hypovolaemia (i.e. pre-renal failure –> renal failure)
- renal dz without renal failure usually doesn;t cause obvious CS or clinical pathology changes
- renal failure when >70% nephrons lost
Causes - primary renal failure
- congenital
- interstitial nephritis
- GN
- PN
- amyloidosis
- neoplasia
CS - primary renal failure
- depression, anorexia, weight loss
- polydipsia and polydipsia
- oedema and diarrhoea
- pyrexia and colic signs
- encephalopathy
- oral mucosal ulceration
- excessive tooth tartar
Urinalysis - primary renal failure
- proteinuria
- casts
- wbcs and bacteria
- haematuria
- inability to concentrate urine (isossthenuria is SG 1.008 - 1.014)
- increased urine GGT (GGT: creatinine ratio to correct for variations in urine flow)
Serum biochem - primary renal failure
• azotaemia – increased urea and creatinine • hyperkalaemia • hyponatraemia • hypercalcaemia • hypophosphataemia
Tx - ARF
– restore circulating volume (0.9% NaCl 40-80
ml/kg/day)
– diuresis (20% mannitol and furosemide IV)
Tx - CRF
– no specific treatment
– supportive only
– ad lib salt and water
– high quality diet
When do foals bladders tend to rupture?
usually during or soon after parturition - inherent bladder wall weakness?
Ddx - ruptured bladder
- tenesmus
- straining to defaecate (e.g. retained meconium)
- note the caudal position of the HL in foals straining to urinate
Outline bladder rupture in foals
- no sex predisposition
- previosuly thought more common in colts (narrow pelvis and long urethra)
- tears on dorsal aspect of bladder
CS - ruptured bladder in foal
- within first 2-3 days of life
- dysuria: frequent attempts to urinate with only small amounts voided
- progressive depression and abdominal distension
- ventral and preputial oedema
Outline urinary tract rupture secondary to infection
- urachus, bladder or ureters
- birth to 2 months old
- hx of other illness
- easy to miss because deterioration in clinical status can be mistakenly attributed to pre-existing dz
Dx - ruptured bladder
- peritoneal fluid: serum creatinine ratio >2.1
- ultrasound
Aid-base and electrolyte derangements in ruptured bladders
- azotaemia (failure to excrete)
- hyperkalaemia (failure to excrete, leads to cardiac arrhythmias)
- hyponatraemia (loss of renal regulation, continued intake of water)
- metabolic acidosis (loss of renal regulation, third spacing causes hypovolaemia and poor perfusion)
- respiratory acidosis (compression of diaphragm)
Management - ruptured bladder
• Emergency surgery is usually not required
– manage medically first and stabilise before
surgery
– IV fluids
– peritoneal drainage
• Good outcome (>80%) with surgery if
performed on a stabilised foal
Pre-operative stabilisation for ruptured bladder
• Restore circulating volume – 0.9% NaCl – Hartmann’s solution • Dextrose and insulin to promote intracellular movement of potassium – if not successful - calcium or bicarbonate • Drain abdomen and peritoneal lavage • Intranasal oxygen
