Surgical Disorders of the Urinary Tract & Umbilicus

Question 1

How is endoscopy used to examine the urinary tract?

Answer 1

1. Evaluation of urine outflow from ureters - Every 20-45 seconds under xylazine sedation
2. Catheterisation of ureters - Confirm unilateral / bilateral renal/ureteral disease

Question 2

How is ultrasound used to examine the urinary tract?

Answer 2

• Transrectal: Bladder in adults
• Transcutaneous: Kidneys, Bladder, Umbilicus
• Guided needle biopsy of kidney(s)

Question 3

When might a nephrectomy be indicated in horses?

Answer 3

Renal neoplasia
Pyelonephritis non-responsive to medical treatment

Question 4

A ruptured bladder is most commonly seen in which horses?

Answer 4

Foals 1-5do

Question 5

Why does a ruptured bladder occur in foals?

Answer 5

More common in colts
Usually occur during parturition but clinical signs take time to develop
Uncommon in adult horses but can occur

Question 6

What are the clinical signs of a ruptured bladder in foals?

Answer 6

• Depression / off suck
• Progressive abdominal distension
• Mild / moderate colic
• Increased frequency of urination and small urination volume, or no urination

Question 7

What signs of a ruptured bladder are seen in haematology and bichemistry?

Answer 7

• Hyperkalaemia
• Low sodium and chloride
• Dehydration
• Metabolic acidosis

Question 8

How else can a ruptured bladder be diagnosed?

Answer 8

Peritoneal fluid analysis
Ultrasonography
Radiography & contrast studies

Question 9

How does the result of a peritoneal fluid analysis confirm a ruptured bladder?

Answer 9

Peritoneal creatinine more than double serum creatinine

Question 10

Before treating a ruptured bladder what must be done?

Answer 10

Stabilisation prior to GA as hyperkalaemia can cause fatal arrythmias
- Abdominal drainage of urine (slow) – reduce K+ but also improves ventilation
- Rule out concurrent disorders e.g. sepsis
- Antibiotics
- Check IgG status

Question 11

How are foals stabilised to reduce the hyperkalaemia?

Answer 11

i.v. saline / Hartmann’s solution
+/- sodium bicarbonate
Calcium borogluconate
Insulin / glucose

Question 12

How is bladder rupture in foals treated?

Answer 12

Surgical repair via midline laparotomy with resection of umbilicus and urachus

Question 13

Are uroliths more common in male or female horses?

Answer 13

Males (more common) - can block ureter
Females - remain in bladder and cause mild haemorrhage during urination

Question 14

Describe the two types of calcium carbonate uroliths seen in horses

Answer 14

Type I (more common) – spiculated, yellow/green
Type II – smooth & white

Question 15

Describe the history and presenting signs of urolithiasis

Answer 15

Haematuria
Stranguria
+/- pollakiuria, pyuria or incontinence

Question 16

How is urolithiasis diagnosed?

Answer 16

Rectal examination
External palpation
Ultrasonography
Endoscopy

Question 17

How is urolithiasis in horses treated?

Answer 17

1. Surgical removal
   - Laparotomy
   - Laparoscopy
   - (Incision directly over urolith if in urethra)
2. Electrohydraulic / laser lithotripsy
3. If the horse cannot urinate due to a distal urethral obstruction, a temporary perineal urethrotomy may be needed

Question 18

What is sabulous cystitis?

Answer 18

Secondary problem, consequent to bladder paralysis or other physical or neurologic disorders interfering with complete bladder emptying

Question 19

What is the cause of bladder eversion?

Answer 19

Due to excessive straining
Parturition or foaling

Question 20

The umbilicus is composed of?

Answer 20

One vein and two arteries

Question 21

Describe what normally happens to the umbilicus after parturition

Answer 21

• Umbilical cord breaks naturally immediately after parturition
• Iodine / chlorhexidine should be applied immediately to the umbilical stump
• Should progressively dry up & disappear over 4-6 weeks
• Investigate if moistness >24h, swelling / pain on palpation or if the foal is febrile

Question 22

What is a patent urachus?

Answer 22

Urachus fails to close spontaneously or can reopen if sepsis occurs
Moisture around umbilicus +/- dripping of urine

Question 23

How should a patent urachus be treated?

Answer 23

• Check for concurrent septicaemia/septic arthritis/ physitis
• Assess IgG status
• Medical: Antibiotics, Topical agents (concentrated phenol or 7% iodine solution or with silver nitrate applicators)
• Often self-resolving
• Surgical (if needed) Resection of the urachus

Question 24

When is umbilical sepsis seen?

Answer 24

First 1-2 weeks of life but can occur later
Foal depressed & off suck
Swollen, painful umbilicus

Question 25

How is umbilical sepsis diagnosed and treated?

Answer 25

• Ultrasonography of the umbilicus reveals enlargement of structures
• Assess IgG status & assess for concurrent septicaemia / septic arthritis / physitis
• Blood culture, haematology & biochemistry
• Systemic antibiotics
• Surgical resection if no response to therapy / deterioration

Question 26

How are umbilical hernias assessed?

Answer 26

Most are small & will resolve with time
Determine size & whether reducible / non reducible

Question 27

If an umbilical hernia is non-reducible what should be done?

Answer 27

• If defect is non-reducible, immediate surgery is needed
• Owner must evaluate daily
• Can cause strangulation of bowel if entrapped

Question 28

When is surgical repair of an umbilical hernia indicated?

Answer 28

• Large defect (>3-5cm)
• Defects persists more that 6 months
• Defect enlarges
• Associated with colic