Large animal urinary tract diseases Flashcards
urolithiasis - predisposing factors
Castrated males - narrower urethra
Diet has major influence – high concentrate / low roughage, high phosphate diets/low calcium diet, high magnesium diets, alkaline urine
Dehydration
Urinary tract infection
urolithiasis - types of uroliths
calcium (apatite and carbonate) phosphate (calcium phosphate and magnesium ammonium phosphate [struvite]) silicate oxylate diet dependent
urolithiasis - site of obstruction
urethral (vermiform) process in small ruminants > distal sigmoid flexure
distal sigmoid flexure in cattle
urolithiasis - clinical signs - early
haematuria, dysuria, crystals on prepuce
urine dribbling
tail flagging & colic signs
urolithiasis - clinical signs - later
anorexia, depression
preputial swelling
abdominal distension
recumbent, seizures and death
urolithiasis - diagnosis
history and clinical signs
azotaemia, hyperkalaemia, hyponatraemia, acidosis
ultrasonography
radiography
urolithiasis - complications
bladder rupture – abdominal distension and uroperitoneum
urethral rupture – swollen prepuce
hydronephrosis – requires chronic obstruction, diagnosis via ultrasonography
urolithiasis - management
Medical management – incr diet calcium: phosphate ratio, urinary acidification
Surgical managemen – urethral process amputation, perineal urethrostomy, tube cystotomy
Amyloidosis
inflammation drives serum amyloid A (SAA) production: glomerulopathy
loss of glomerular function results in protein losing nephropathy
amyloidosis - clinical signs
oedema, weight loss, chronic diarrhoea
proteinuria, hypoalbuminaemia, azotaemia
raised serum fibrinogen, SAA, globulins
amyloidosis - treatment
none
Enzootic haematuria - causes
cattle and sheep grazing bracken - contains ptaquiloside carcinogens requires chronic (>12 months exposure)
Enzootic haematuria - effects
bladder wall neoplasia – haemorrhagic cystitis, haematuria
anaemia
differentiate from haemoglobinuria
Ulcerative posthitis/vulvitis - define + cause
‘pizzle rot’ in small ruminants
ulcerative bacterial infection of prepuce and vulva mucous membranes
Corynebacterium renale
high protein diets appear to predispose
Ulcerative posthitis/vulvitis - clinical signs
pain, loss of condition, decreased fertility/libido
Ulcerative posthitis/vulvitis - management
penicillin, NSAIDs, reduce dietary protein <16%
Pyelonephritis
in FA & horses
ascending infection of the urinary tract
most common renal disease in cattle
post parturition and post service/covering
following metritis and urolithiasis
Pyelonephritis - acute clinical signs
pyrexia, anorexia, depression, colic signs
decreased milk yield
stranguria, polyuria, hematuria, pyuria
Pyelonephritis - chronic clinical signs
weight loss, colic, decreased milk yield, diarrhoea, polyuria, anemia, less obvious signs of urinary tract infection
Pyelonephritis - microbiology
coliforms, Proteus sp, Klebsiella sp, Enterobacter sp
A. pyogenes
rarely C. renale
Pyelonephritis - diagnosis
clinical signs and rectal palpation
pyuria, haematuria, proteinuria
azotaemia
urine culture?
Pyelonephritis - treatment
long term (14-21 days) broad spectrum AB’s oxytetracycline or penicillin/aminoglycosides
umbilical infection
umbilicus can be portal of entry of infection
Infection can localise there following haematogenous spread from gut, other sites of sepsis or as part of generalised septicaemia
Arteries and urachus become infected more commonly than vein
umbilical infection - common pathogens
Escherichia coli Actinobacillus equuli klebsiella spp Pseudomonas spp. Bacillus spp. Staphylococcus aureus Streptococcus spp. Enterococcus spp Clostridium spp. mixed infections common
umbilical infection - clinical signs
Fever, malaise, lethargy
Heat, pain, swelling and discharge from umbilicus
Localising signs are not present in every case, particularly when there is generalised septicaemia
umbilical infection - treatment - surgical
resection
Prevents spread of infection to other sites
Animals with generalised septicaemia may not be good candidates for anaesthesia
umbilical infection - treatment - medical
broad spec antibiotics
Monitor with ultrasonography, and if umbilicus continues to enlarge, change antibiotic or consider surgery
umbilical infection - antibiotic choice
Ceftiofur Trimethoprim-sulphonamide Aminoglycosides – care in very young animals- nephrotoxicity Penicillins and other beta-lactams Cephalosporins
umbilical hernia
differentiate umbilical infection from hernia
small hernias (<2 cm) resolve over first 2 months
larger hernias may require surgical treatment
dangerous only if strangulating
patent urachus
has been closed then opens
infection
prolonged recumbency
persistent urachus
open since birth
excessive torsion during parturition?
may need cautery or surgical resection
renal failure in horses
primary less common than failure secondary to hypovolaemia
renal disease without renal failure usually does not cause obvious clinical signs or clinical pathology changes
renal failure when >70% nephrons lost
Causes of primary renal failure
congenital interstitial nephritis glomerulonephritis pyelonephritis amyloidosis neoplasia
clinical signs
depression, anorexia, weight loss polydipsia and polydipsia oedema and diarrhoea pyrexia and colic signs encephalopathy oral mucosal ulceration excessive tooth tartar
urinalysis
proteinuria
casts
white cells and bacteria
haematuria
inability to concentrate urine – isosthenuria: SG 1.008-1.014
increased urine GGT - GGT: creatinine ratio to correct for variations in urine flow
serum biochemistry
azotaemia – increased urea and creatinine hyperkalaemia hyponatraemia hypercalcaemia hypophosphataemia
treatment - acute
restore circulating volume
diuresis (20% mannitol and furosemide IV)
treatment - chronic
no specific treatment
supportive only
ad lib salt and water
high quality diet
Ruptured bladder and uroperitoneum in foals - timing of rupture
usually occurs during or soon after parturition
History of previously normal urination does not rule out ruptured bladder in cases that rupture later
Must differentiate from tenesmus/straining to defaecate
Bladder rupture detected soon after parturition
No sex predisposition
Previously thought to be more common in colts - narrow pelvis and long urethra
Tears on dorsal aspect of bladder
bladder rupture - clinical signs
Signs are normally present within the first 2–3 days of life
Dysuria: frequent attempts to urinate - small amounts voided
Progressive depression and abdominal distension
Ventral and preputial oedema
Urinary tract rupture secondary to infection
Urachus, bladder or ureters
From birth to around two months of age
Usually history of other illness
Easy to miss because deterioration in clinical status can be mistakenly attributed to pre-existing disease
bladder rupture - diagnosis
Peritoneal fluid: Serum creatinine ratio > 2:1
Ultrasonography
bladder rupture - management
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
