Large animal urinary tract diseases

Question 1

urolithiasis - predisposing factors

Answer 1

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

Question 2

urolithiasis - types of uroliths

Answer 2

calcium (apatite and carbonate) 
phosphate (calcium phosphate and magnesium ammonium phosphate [struvite]) 
silicate 
oxylate 
diet dependent

Question 3

urolithiasis - site of obstruction

Answer 3

urethral (vermiform) process in small ruminants > distal sigmoid flexure
distal sigmoid flexure in cattle

Question 4

urolithiasis - clinical signs - early

Answer 4

haematuria, dysuria, crystals on prepuce
urine dribbling
tail flagging & colic signs

Question 5

urolithiasis - clinical signs - later

Answer 5

anorexia, depression
preputial swelling
abdominal distension
recumbent, seizures and death

Question 6

urolithiasis - diagnosis

Answer 6

history and clinical signs
azotaemia, hyperkalaemia, hyponatraemia, acidosis
ultrasonography
radiography

Question 7

urolithiasis - complications

Answer 7

bladder rupture – abdominal distension and uroperitoneum
urethral rupture – swollen prepuce
hydronephrosis – requires chronic obstruction, diagnosis via ultrasonography

Question 8

urolithiasis - management

Answer 8

Medical management – incr diet calcium: phosphate ratio, urinary acidification
Surgical managemen – urethral process amputation, perineal urethrostomy, tube cystotomy

Question 9

Amyloidosis

Answer 9

inflammation drives serum amyloid A (SAA) production: glomerulopathy
loss of glomerular function results in protein losing nephropathy

Question 10

amyloidosis - clinical signs

Answer 10

oedema, weight loss, chronic diarrhoea
proteinuria, hypoalbuminaemia, azotaemia
raised serum fibrinogen, SAA, globulins

Question 11

amyloidosis - treatment

Answer 11

none

Question 12

Enzootic haematuria - causes

Answer 12

cattle and sheep grazing bracken - contains ptaquiloside carcinogens
requires chronic (>12 months exposure)

Question 13

Enzootic haematuria - effects

Answer 13

bladder wall neoplasia – haemorrhagic cystitis, haematuria
anaemia
differentiate from haemoglobinuria

Question 14

Ulcerative posthitis/vulvitis - define + cause

Answer 14

‘pizzle rot’ in small ruminants
ulcerative bacterial infection of prepuce and vulva mucous membranes
Corynebacterium renale
high protein diets appear to predispose

Question 15

Ulcerative posthitis/vulvitis - clinical signs

Answer 15

pain, loss of condition, decreased fertility/libido

Question 16

Ulcerative posthitis/vulvitis - management

Answer 16

penicillin, NSAIDs, reduce dietary protein <16%

Question 17

Pyelonephritis

Answer 17

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

Question 18

Pyelonephritis - acute clinical signs

Answer 18

pyrexia, anorexia, depression, colic signs
decreased milk yield
stranguria, polyuria, hematuria, pyuria

Question 19

Pyelonephritis - chronic clinical signs

Answer 19

weight loss, colic, decreased milk yield, diarrhoea, polyuria, anemia, less obvious signs of urinary tract infection

Question 20

Pyelonephritis - microbiology

Answer 20

coliforms, Proteus sp, Klebsiella sp, Enterobacter sp
A. pyogenes
rarely C. renale

Question 21

Pyelonephritis - diagnosis

Answer 21

clinical signs and rectal palpation
pyuria, haematuria, proteinuria
azotaemia
urine culture?

Question 22

Pyelonephritis - treatment

Answer 22

long term (14-21 days) broad spectrum AB’s 
oxytetracycline or penicillin/aminoglycosides

Question 23

umbilical infection

Answer 23

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

Question 24

umbilical infection - common pathogens

Answer 24

Escherichia coli 
Actinobacillus equuli 
klebsiella spp 
Pseudomonas spp. 
Bacillus spp. 
Staphylococcus aureus 
Streptococcus spp. 
Enterococcus spp 
Clostridium spp. 
mixed infections common

Question 25

umbilical infection - clinical signs

Answer 25

Fever, malaise, lethargy Heat, pain, swelling and discharge from umbilicus Localising signs are not present in every case, particularly when there is generalised septicaemia

Question 26

umbilical infection - treatment - surgical

Answer 26

resection Prevents spread of infection to other sites Animals with generalised septicaemia may not be good candidates for anaesthesia

Question 27

umbilical infection - treatment - medical

Answer 27

broad spec antibiotics | Monitor with ultrasonography, and if umbilicus continues to enlarge, change antibiotic or consider surgery

Question 28

umbilical infection - antibiotic choice

Answer 28

``` Ceftiofur Trimethoprim-sulphonamide Aminoglycosides – care in very young animals- nephrotoxicity Penicillins and other beta-lactams Cephalosporins ```

Question 29

umbilical hernia

Answer 29

differentiate umbilical infection from hernia small hernias (<2 cm) resolve over first 2 months larger hernias may require surgical treatment dangerous only if strangulating

Question 30

patent urachus

Answer 30

has been closed then opens infection prolonged recumbency

Question 31

persistent urachus

Answer 31

open since birth excessive torsion during parturition? may need cautery or surgical resection

Question 32

renal failure in horses

Answer 32

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

Question 33

Causes of primary renal failure

Answer 33

``` congenital interstitial nephritis glomerulonephritis pyelonephritis amyloidosis neoplasia ```

Question 34

clinical signs

Answer 34

``` depression, anorexia, weight loss polydipsia and polydipsia oedema and diarrhoea pyrexia and colic signs encephalopathy oral mucosal ulceration excessive tooth tartar ```

Question 35

urinalysis

Answer 35

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

Question 36

serum biochemistry

Answer 36

``` azotaemia – increased urea and creatinine hyperkalaemia hyponatraemia hypercalcaemia hypophosphataemia ```

Question 37

treatment - acute

Answer 37

restore circulating volume | diuresis (20% mannitol and furosemide IV)

Question 38

treatment - chronic

Answer 38

no specific treatment supportive only ad lib salt and water high quality diet

Question 39

Ruptured bladder and uroperitoneum in foals - timing of rupture

Answer 39

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

Question 40

Bladder rupture detected soon after parturition

Answer 40

No sex predisposition Previously thought to be more common in colts - narrow pelvis and long urethra Tears on dorsal aspect of bladder

Question 41

bladder rupture - clinical signs

Answer 41

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

Question 42

Urinary tract rupture secondary to infection

Answer 42

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

Question 43

bladder rupture - diagnosis

Answer 43

Peritoneal fluid: Serum creatinine ratio > 2:1 | Ultrasonography

Question 44

bladder rupture - management

Answer 44

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