Urogenital Large Animal BRAD Flashcards

1
Q

What is the sedation/anaesthesia for small ruminant and bovine

A

Sedation

Small Ruminant
- Zoletil 100 (Tiletamine & Zolazepam): Short term procedures, IV/IM, onset 10min
- ZKX (Ket, Xylazine, Zoletil): IM/IV, Last several hours, gives 1-2hrs analgesia

Bovine
a) Standing: Xylazine +- Butorphanol & Ketamine: IV/IM +- Acetylpromazine: IV
b) Recumbent: Xylazine (x2) & Ketamine (x4-8): IV/IM

Anaesthesia

Bovine
a) Caudal Epidural - 2% lignocaine HCL: C1-2, 18G 1.5inch
Prevents ab contractions but NOT suited for C-section & shouldn’t affect motor control
b) Local Anaesthetic
Paralumbar Laparotomy
- Paravertebral: T13-L3, 20-18G long, 10ml above & below transverse processes
Dis: ↑ technique & time till effect
–> hard in well-conditioned beef cows
- Line or Inverted L: Toxic dose Lignocaine HCL – CS of systemic toxicity

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2
Q

Describe small ruminant urolithiasis

A

Hosts: Castrated males, occasionally intact males

Cause: Dietary and management related

PF:
- High concentrate ration
- Low fibre/ roughage
- Incorrect Ca:P ratio
- High Mg diet
- Alkaline urine
- Long/convoluted/narrow urethra
- Texel & Scottish blackface (breeds)

Aetiology:

Aetiology:
- Phosphorus is recycled through saliva & excreted in faeces
- High grain/low roughage diets ↓ saliva production → ↑ Urinary P excretion
- Increased urine output (If acidic) can prevent formation of uroliths

Site of Obstruction: Most lodge at Urethral process! (N/A in alpacas), second most common is Distal sigmoid flexure
Multiple small uroliths in bladder and along urethra

CS:

  • Bleating/vocalising
  • Haema/dys/stranguria
  • Tail flagging
  • Ab pain (Stretch limbs)
  • Recumbency
  • Preputial & ab swelling
  • subcutaneous oedema
  • Seizure, cadiovascular collapse
  • Death
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3
Q

What are the types of calculus?

A

Calcium Carbonate: Small gold beads, pastures high in clover or oxalate containing plants

Struvite: Sand-like Mg ammonium phosphate,
High PO4 or Mg diets – common in feedlot/high grain

Apatite: Ca-PO4, high Ca & oxalate intake

Silica: Semi-arid region

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4
Q

How to diagnose, prevent and treat urolithiasis?

A

Dx:

  • US
  • Radiography
  • Biochem: ↑ BUN (Blood Urea Nitrogen) /creatine/elevated muscle enzymes AST/CPK, Hyper/normokalaemia, hypoNa, hypoCl, acidosis

Prevent:
- 2-5% (30g/day) Dietary NaCl or AmmoniumCl (0.5-1%) / 10g/day
- Low K & Ca diet
- Ca:PO4 2:1 (Grass hay 1:1, Lucerne 5:1)
- DON’T use horse feed
- +-? Castrate >6m –? allow development of normal urethral diameter.

Treat:
- IV catheter & fluids

  • Sedate: Diazepam +- ketamine & Oxygen + isoflurane as needed
    –-> AVOID xylazine (Hypotension & sleepy)
  • Insert Allis forceps into preputial cavity → Grasp & pull-out fold → Repeat until penis everted
  • Sx:
    Ex-lap, cystotomy: evacuate bladder calculi.
  • retrograde lavage of bladder and urethra using urinary catheter, tube cystotomy +- Perineal urethrostomy if obstruction distal to sigmoid flexture
  • Non-Sx:
    Grasp penis w/ gauze → Amputate urethral process & wait for re-obstruction (70-80% do) → Insert sterile polypropylene Rutner catheter (5-10) retrograde → Lavage bladder w/ warm saline & Renacidin (Mg-Carbonate, Citric acid – 2x daily for 2 weeks)
  • Retrograde Catheterisation: Urethral diverticulum at ischial arch prevents retrograde passage into urinary bladder – NOT recommended as unsuccessful/further trauma of the uretha
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5
Q

How to do a Cystotomy?

A

Method:

  • Exteriorise penis, resect urethral process, insert 5-10 polypropylene catheter retrograde to the diverticulum or obstructing stone
  • Place slip knot of sterile tensofix around glands w/ long ends to allow extension of penis during surgery
  • Caudal ventral midline incision → Pack intestines with lap sponge & exteriorise bladder
  • 1-2cm incision at bladder apex → suction urine → Explore & remove large stones
  • Smaller stones removed w/ catheter tip syringe & suction tube to suck out calculi
  • Pass catheter normograde & lavage bladder to empty urethra, catheters should pass easily once urethra is cleared
  • Lavage/incise penis over calculi & remove
  • Suture urethral incisions at urethra & tunica albuginea w/ 4-0 Vicryl/monosyn simple interrupted pattern w/ catheters in place to avoid incorrect suture placement.
  • Anchoring sutures btwn tunica & fascia of caudal thigh → then urethral mucosa to skin SI (simple interrupted) sutures
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6
Q

What is tube cystotomy?

A

Method:
- Move bladder to one side of laparotomy incision & mark where apex of empty bladder contact’s the body wall
- Stab incision (0.5cm) in skin/wall ~3-5cm from edge of midline incision
- Insert 24 Foley catheter through stab wound & thread tip into cystotomy incision
- Suture bladder w/ SI 1-0/2-0 Vicryl, last suture should be close to catheter entry and seal the hole.
- Place purse string suture around catheter inside bladder & as the purse string is tightened, invert original linear incision and entry site of the Foley catheter.
- Fill Foley balloon w/ saline & distend bladder to check for leaks → Rx last step & re-test
- Once bladder is sealed, pull bladder to peritoneum at entry of foley & suture in place via purse-string
- Place condom over end of foley for 1 way valve & close ventral laparotomy incision
- Maintain tube cystostomy until urine dripping from prepuce for 48hrs → Clamp & monitor urination
- Removed: Able to urinate, empty bladder, no pain Left for 5-7d: Partial urination

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7
Q

Advantages and disadvantages of tube cystostomy?

A

Px: 80% good prognosis

Adv:
- Maintain breeding function in intact males
- Don’t have to remove all small calculi
- Avoid risk of stricture formation with Perineal urethrostomy

Dis:
- Increased cost
- Re-obstruction is possible

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8
Q

What is a Perineal Urethrostomy?

A

Indication: All patients with a ruptured perineal urethra

Methods:
6cm Incision on midline of perineum ~4-6cm ventral to anus and either:
a)
- Penis is elevated to incision & stay sutures (0 PDS, vicryl) are placed btwn perineal fascia overlying semimembranosus m. & tunica albuginea of the penis
- 2cm Incision on caudal & ventral midline of penis (Over urethral groove)
- Tunica albuginea is sutured to SC tissue adj/ to skin (0 PDS, vicryl)
- Urethral mucosa is sutured to skin edges of wound (3-0 monosyn, 4-0PDS)

b)
- Penis is dissected ventral to incision & proximal stump exits wound
- Stay sutures placed circumferentially around penis from tunica albuginea to skin
- Urethral mucosa is sutured to cut edge of tunica albuginea

Complications:
- Urine scalding (Too prox. To perineum)
- Haemorrhage post-op
- Stricture (Esp. young)
- Rx obstruction (50-70% <1yr)

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9
Q

Describe urine pooling in cows

A

Consequences: Significant cause of infertility due to incompetent constrictor vestibuli m.

Method:
A) Caudal Urethral Extension
- Foley catheter placement in urethra
- Create/invert/Connell pattern suture 2 lateral mucosal flaps parallel to catheter

B) Vestibulovaginal Cerclage Suture Technique:
- 2x PDS purse-string around vulvo-vestibular junction, caudal to urethral fold
- Tightened so only 1 finger can be inserted in vagina
- Resolved in 89% cows, Pregnancy rates 74% vs 35% in control

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10
Q

What are the reasons to castrate production animals?

A
  • Tractability, handling and management practices
  • Prevent unwanted breeding
  • Promote weight gain
  • Correct scrotal/inguinal hernia
  • Testicular malignancy, orchitis, abscess or injury

Castrate:
- Calves < 2 months
- Pigs, sheep, goats 2 weeks
- Camelids
- Camels

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11
Q

How to do a small ruminant castration?

A
  • Diazepam +- Ketamine IV & lignocaine at testis/cord, meloxicam PO (Orally)/SC
  • Lateral recumbency w/ tied leg OR DR (Dorsal recumbency), clip/aseptic prep/drape distal scrotum
  • Incise distal 3rd of scrotum & strip out testis until 5cm cord is showing
  • Incise parietal tunic longwise down the exposed spermatic cord
  • Expose pampiniform/vas deferens via inserting Kelly haemostats into the tunic incision and apply transfixation ligature to pampiniform and vas deferens. (0 Vicryl/Monosyn)
  • Transect/emasculate testicle & ligate cord/tunic 1-2cm proximal to other ligature
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12
Q

What is a hemicastration?

A

Indication: Orchitis, scrotal hernia

  • Incise long axis of scrotum parallel to testicle
  • Vaginalis opened for inguinal reduction BUT closed in most bulls to ↓ time/risk of hernia
  • Open: Spermatic cord is ligated individually
  • Closed: Combo of emasculation/transfix ligation of spermatic cord
  • SC & tunic closure, pack w/ gauze → DON’T close skin as it may cause excess fluid & swelling
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13
Q

How to do a calf castration?

A
  • Xylazine +- ketamine & incise on side of scrotum → open or closed ligation
  • Horizontal incision: Better drainage
  • Ventral: Must go from caudoventral to cranioproximal to prevent edges healing too quickly
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14
Q

How to do a South American Camelid Castration?

A
  • Xylazine & Ket IV/IM, Atropine if HR <30bpm, DR (dorsal recumbency) w/ head to one side and towel under neck to prevent Aspiration
  • Clip & drape → 2x Pre-scrotal incisions & push testes cranially → Open or closed. Ligate pampiniform plexus and vas deferens then tunic
  • Leave scrotal incision open to heal via 2nd intention & give tetanus prophylaxis, PPG, Flunixin
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15
Q

How to do a piglet castration?

A
  • Xylazine, Ketamine & Butorphanol IM, 10m till effect, lasts for 30 minutes, Cradle or DR
  • Closed technique & transfixation ligatures, watch for herniation
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16
Q

How to do a camel castration

A
  • Fast for 12-24hrs prior to reduce aspiration risk, MUST be 3yrs & descended testes
  • Xylazine & wait 15m → Ketamine into cush OR Medetomidine, Ket & Butorphanol (10m)
  • Apply hobbles/collar/loin rope once recumbent & apply intra-testicular lignocaine
  • Pre-scrotal incision and push testes ventral to avoid defecation
  • Open/closed transfixation & emasculation, work fast to avoid teste retraction
  • Close skin incision (~8% infection rate) → Tetanus, Ab +- Flunixin
17
Q

What is camel anaesthesia?

A
  • Xylazine → Ketamine 15 minutes later: IM, cush
  • Medetomidine, Butorphanol & Ketamine: IM, 10 min till recumbent – Reverse (Atipamezole)
18
Q

How to do a Vasectomy?

A
  • 1-2cm vertical incision in scrotum skin/tunic proximal to testes adj. to vas deferens
  • Incise common vaginal tunic & separate/remove 3cm of vas deferens (Sit alone from others)
  • Ligate each cut ends to discourage recanalization
  • Leave common vaginal tunic open & close skin w/ absorbable or non-absorbable suture & repeat on other side
  • +- Submit vas deferens for histological confirmation
  • Restrict breeding for 4 weeks & should be checked before reintroduction to herd
19
Q

How to a Caudal Epididymectomy?

A

Indication: Alternative to vasectomy to prevent potential damage to pampiniform plexus

  • Xylazine & local infusion/caudal epidural & prep
  • Assistant grasps neck of scrotum and forces testicles to the ventral scrotum
  • 1-2cm Incision lateral to median raphe over the tail of epididymis into the skin & common vaginal tunic (CVT)
  • Exteriorize tail via grasping with gauze or allis tissue forceps → separate/ligate/transect vas deferens from tail
  • Ligate/transect body of epididymis from testicle & Rx on other side
  • Close CVT & skin separately w/ abs suture
  • Don’t perform vasectomy for 2wks +- perform fertility exam prior to reintroduction & yearly
20
Q

What is persistent frenulum?

A
  • Restrict feed 12 hours prior, sedate with xylazine and acepromazine
  • Extend penis, grasp frenulum at attachment to penis and prepuce. Resect with mayo scissors
  • Control bleeding with electrocautery or suture ligation
  • 2-3 weeks rest from breeding
21
Q

What are penile fibropapillomas?

A

Hosts: Young bulls: Age related immunity
Cause: Bovine papilloma virus
Consequence: Infertility (through Haemorrhage into ejaculate)
Treat: Often have pedicle: Transect and ligate

22
Q

What are causes of penile/preputial swelling in bulls?

A

DDx:
- Penile haematoma
- Preputial laceration complex
- Ruptured urethra: Causes a diffuse ventral abdominal oedema (Water belly)

23
Q

What is a penile haematoma?

A

Location: Distal sigmoid flexure

Cause: Sudden bending of erect penis during service

Pathogenesis:
- Rupture arises from dorsal/crural canal and tunica albuginea of the corpus cavernosum penis
- Haematoma forms dorsal to sigmoid except at rest is located proximal to the base of the scrotum

Treatment:
- GA or sedate, lateral recumbency with local infiltration & upper hindleg tied up to expose pre-scrotal area
- Incise over lateral prepuce, 10-15xm through skin and SC –> Incise and evacuate haematoma
- Suture albuginea rent on dorsal surface of distal sigmoid flexure with simple interrupted absorbale –> 3-7cm in spiral location
- Resect adhesions & Close fascia, subcut and skin with vertical mattress pattern

Post-op:
- PPG IM BID 5-7d +- Flunixin IV SID OR Meloxicam SC once every third day

Prognosis:
- Improved with > 2m sexual rest

  • <20cm diameter: Success ~80%
  • > 20cm: ~75% after Sx or 33% after medicine
  • Complications: Erectile dysfunction, failed ejaculation, limited extension, recurrence
24
Q

Explain preputial lacerations/trauma in cattle

A

Hosts: Bos indicus breeds due to pendulous prepuce

Medical Treatment:
- Sling: Change daily
- Cold hosing & Betadine lavage
- Procaine penicillin IM BID 3-5 days
- NSAIDs
- Tropical nitrofurazone
- Do medical treatment 2-4 weeks before evaluation for surgery: Don’t perform surgery too soon after injury as most will be infected, inflamed and oedematous at time of diagnosis

Surgery: Amputation
- Xylazine IV or cast bull in LR (lateral recumbency) w/ upper hind tied back
- Extend penis & apply torniquet to muco-cutaneous junction
- Circumferential incision around prepuce proximal & distal to area being removed
- Connect two incisions longitudinally, leaving prepuce to cover erect penis
- SI Sutures placed at 3, 6, 9, 12 O’clock & suture the proximal/distal mucous membranes together (0 Monosyn)
- Avoid continuous suture patterns as can cause strictures BUT overlap sutures to ↓ haemorrhage
- Penrose drain sutured over end of penis w/ 2x SI sutures to allow urine flow
- After surgery, Penile & preputial cavity retaining tube (2.5 x 15cm) is taped onto prepuce for 10-14d

Prognosis:
- Medical: 59%
- Surgical: 85%

  • Improved via: Penile extension at surgery, Preputial resection performed if Amputation was required, surgery performed under anaesthesia in clean surgery suite
  • If genetic value can be replaced, bull is only used for <2 breeding sessions after recovery, bull is used in a single breeding season per year, and tx would be at a hospital, CULLING is more economic
25
Q

Describe the pathogenesis of penile deviation?

A

Types: Corkscrew (mat be Heritable, electro-ejaculation may cause), Ventral (Electro-ejaculation), ‘S’ deviation

Aetiology: Dorsal penile ligament slips off side of penis

Sx:
1. Apical Ligament Splitting/Interweaving
- Risks: Formation of vascular shunts
- Longitudinal incision is made in the apical ligament → isolation of 2mm wide portion of the ligament at either side of the incision
- 2mm segment remains attached at its proximal margin & threaded onto a needle → needle is passed through tunica albuginea in a interweaving pattern.
- Apical lig. is anchored to distal aspect of penis
2. Fascia Latae Autograft
- Adv: Better success rate, easier under GA, no vascular shunting
- 2 x 20cm portion of fascia latae from craniolateral thigh is obtained
- Apical lig. is then divided on dorsal midline to expose t. albuginea
- An Autograft is placed on the dorsal penis & sutured to t. Albuginea (2-0 PDS)
- Apical lig. is sutured closed & anchored to autograft → sexual rest for 60d
Px: Success rate 50%

26
Q

How to achieve a teaser bull?

A

Teaser bull: a bull whose reproductive system has been surgically altered to render him sterile.

Surgery:
1. Vasectomy: Risk of recanalization
2. Epididymectomy: Histopathology to confirm ependymal tissue was resected
3. Penile Translocation:
- Adv: May be best option as it prevents penetration and tx of venereal disease
- Incise lateral to midline as well as along shaft & circumferential around preputial orifice to isolate penis
- Make new prepuital orifice laterally and dissect subcutaneously towards midline, grasp penis and pull throuh to new position. Pull to ventro-lateral abdomen.
- Close original incision, anchor the dorsal penis to ext. rectus m. & suture orifice to new ventro-lateral site
4. Penile Tie Down
- Caudal epidural +- Local infiltration, Incise over penis prox. To sigmoid flexure
- Place stay sutures btwn penile tunica & perineal fascia → Suture SC & skin

27
Q

What is an inguinal hernia?

A

Cause: Swine – Heritable, Cattle - may be heritable
Congenital or acquired via falling/overuse in breeding

Internal/Deep ring: Made of caudal internal ab oblique muscle cranially (Cr)., Caudal border of the aponeurosis of the ext. ab oblique caudally (Cd.)
External/Super Ring: Is a Slit in aponeurosis of ext. ab oblique (Inguinal lig)
Inguinal Canal Contains: Spermatic cord, vaginal tunic, cremaster m., ext. pudendal artery and vein, inguinal lymph vessels, genitofemoral n.
Vaginal Ring Contains: Testicular a./v. (artery/vein), lymphatic, nerves, vas deferens

Surgery:
1. Same-Side Paralumbar Fossa Laparotomy
- Blind suturing of internal inguinal ring (Non-abs) but is more secure than closing external inguinal ring
- Dis: Ineffective if adhesions btwn GIT & spermatic cord, allows retention of testicle
2. Opposite-Side Paralumbar Fossa Laparotomy
- Ext. inguinal ring is closed, useful for hernias w/ incarcerated GIT, easier suture placement
- Dis: Not as secure, potential spermatic cord strangulation, higher recurrence
3. Unilateral Orchiectomy: If hernia recurs, use complete closure of both rings

28
Q
A