Large Animal Surgery Flashcards
(41 cards)
1
Q
What are the leading causes of mortality associated with caesarean sections?
A
Peritonitis and shock
2
Q
What is the appropriate sedation for a standing bovine caesarian?
A
- Xylazine 0.02mg/kg
- +/- butorphanol0.25mg/kg
- +/- ketamine 0.05mg/kg
- 25-30mg acetylpromazine IV
3
Q
What is the appropriate sedation for a recumbent bovine caesarean?
A
- Xylazine 0.05mg/kg + 0.2-0.4 mg/kg Ketamine IV/IM
4
Q
Where is a caudal epidural performed in a cow?
A
Between the 1st and 2nd coccygeal vertebrae
5
Q
What are some clinical signs of systemic toxicity from local infiltration of local anaesthetic?
A
- drowsiness
- convulsions
- respiratory depression
- CV collapse leading to death
6
Q
Where do you perform a paravertebral block on a cow and horse?
A
Cow: T13 - L3
Horse: T18 - L3
7
Q
What is the caesarean surgical approach?
A
- left paracostal
- decompress rumen with needle and suction tubing
- pull edge of the greater omentum off the uterus
- grasp the rear limb of the forelimb and pull the cannon bone to the incision
- push left hand into abdomen and grab the hock or elbow
- lever limb to incision and out of abdomen
- incise from hock/hoof through uterus then amnion
- place chains on legs than pull calf
- clamp cord and transect
- check for 2nd calf
- lavage abdomen and start closure
8
Q
Surgical procedure for a uterine closure?
A
- single layer inverting pattern in uncomplicated surgery
- 2 layer closure more generally accepted
- admin IU oxytocin
9
Q
Porcine Anaesthesia
A
Zoletil 5mg/kg IM + Xylazine 2.5mg/kg IM
- pig must be intubated for longer surgical procedures
10
Q
Where and how is a porcine caesarean performed?
A
- left flank laparotomy
- start incision 5cm ventral to the tuber coxae and extend ventrally
- locate uterus and count piglets
11
Q
What direction is uterine torsion in a bovine usually?
A
- more likely counter clockwise (right broad ligament stretched over top of uterus)
- often involves cervix - palpate torsion of anterior vagina
12
Q
What direction is uterine torsion in an equine normally?
A
- equal distribution between clockwise and counterclockwise
- less likely to have cervical or vaginal involvement
13
Q
Causes of uterine lacerations and tears
A
- dystocia manipulations
- foetotomy
- C-section
14
Q
What is indicative of a diagnosis of uterine tear/lacerations in equine?
A
- toxic left shift with neutropaenia
- ultrasound abdomen
- uterine palpation
- uterine endoscopy
- abdominocentesis: elevated WCC, TP
15
Q
Treatment for uterine tears/lacerations in equine?
A
- conservative: peritoneal lavage, antibiotics, IV fluids
- surgical: attempt blind closure, difficult
- GA and direct suture: preferred, peritoneal lavage and suction,
16
Q
What are the contributing factors for urinary calculi?
A
- high concentrate ration
- low roughage
- incorrect Ca:P ratio
- high magnesium diets
- alkaline urine
- small diameter urethral process
17
Q
Causes of calcium carbonate calculi?
A
- pastures high in clover
- containing oxalate plants
18
Q
Causes of struvite urinary calculi?
A
- magnesium ammonium phosphate
19
Q
Causes of Apatite urinary calculi?
A
- high Ca and oxalate intake
20
Q
Causes of silica urinary calculi?
A
- semi-arid regions
21
Q
Diagnosis of urinary calculi
A
Clinical signs:
- vocalising
- haematuria
- dysuria
- stranguria
- tail flagging
- abdominal pain
Progression:
- anorexia
- signs of depression
- recumbency
- abdominal distention
- preputial swelling
- subcutaneous oedema
Terminal:
- seizures
- cardiovascular collapse
- sudden death
22
Q
Where are the main sites of urinary calculi obstruction?
A
- urethral process
- sigmoid flexure
- usually multiple small uroliths in bladder and along urethra
23
Q
How can urolithiasis be prevented?
A
- add salt to diet at a rate of 2-5%/30g/day
- low K and Ca diet
- don’t castrate until more than 6 months - growing could result in larger diameter urethra
24
Q
What is the approach to a urinary obstructed patient?
A
- bloods
- ultrasound
- IV catheter and fluids
- sedate with 0.2mg/kg of diazepam and apply a nose mask for oxygen and isoflurane as needed
- avoid xylazine in goats due to diuretic effect and profound sedation
- pulls legs forward
- insert Allis forceps into the preputial cavity, grasp a fold and pull out, repeat once more on the everted fold and the penis should evert
- grasp penis with swab, amputate urethral process and insert sterile catheter and lavage retrograde with warm saline
25
Reasons to castrate production animals
- promote weight gain
- better traceability and management
- correct scrotal/inguinal hernia
- younger is better
- calves = less than 2 months
- pigs, sheep, goats = 2 weeks
- camels = 3 years
26
Anaesthesia for small ruminant castration
Diazepam 0.25-0.5mg/kg IV +/- Ketamine 1-2mg/kg IV
27
What is the stepwise surgical technique for small ruminant castration?
- lateral recumbency with upper leg tied forward
- 10-20ml lignocaine
- Meloxicam 1mg/kg PO/SC
- clip, aseptic prep, use window drape over scrotum
- incise distal third of scrotum
- strip out testis until 5cm of cord is showing
- incise the parietal tunic longwise midway down the spermatic cord
- expose pampiniform and vas deferens by inserting Kelly haemostats into the tunic incision ans apply transfixation ligature to pampiniform and vas deferens using 0 vicyrl/monosyn
- emasculate the testis and transect testicle
- 1-2cm proximal from the 1st transfixation ligature - ligate cord/tunic
28
What are the indications for a hemicastration and how is it performed?
- orchitis, scrotal hernia
- an incision made along the long axis of the scrotum, parallel to the testicle
- the tunica vaginalis may be open to to facilitate reduction of an inguinal hernia, however it should stay closed in most bulls to reduce surgery time and the risk of post-operative inguinal hernia
- emasculation and transfixation ligation of the spermatic cord is used
- . The subcutaneous tissues and/or tunics are closed separately prior to skin closure to minimize dead space and post-operative swelling.
- In bulls affected with infection or excessive swelling, the scrotum is closed over gauze or sterile towel packing such that the ventral aspect of the incision in the scrotum is open to provide for drainage.
- complete closure of skin incision
29
Calf castration anaesthesia
- Xylazine 0.05mg/kg IV + Ketamine 2.2mg/kg IV
30
Southern American Camelid Castration Procedure
- Xylazine 0.25mg/kg + Ketamine 2.5mg/kg IV (5 mins apart)
- dorsal recumbency
- head to one side with rolled towel under neck to reduce risk of aspiration
- clip, prep, window drape
- 2x pre-scrotal incisions - push testes cranially
- ligate pampiniform plexus and vas deferens, then tunic
- leave scrotal incision to heal via second intention
- tetanus prophylaxis, PPG, Flunixin
31
Camel Castration
- fast camels for 12-24 hours prior - reduce the risk of regurgitation and aspiration
- make sure old enough for testes to descend into scrotum (usually by 3 years)
- apply hobbles once recumbent
- intra-testicular lignocaine
- can do pre-scrotal incision or push testes to most ventral aspect of scrotum and incise to avoid defecation on scrotal incision
- open or closed castration with transfixation ligatures and emasculation
- tetanus prophylaxis
32
Camel anaesthesia for castration
- Xylazine 1mg/kg IM, wait 15 minutes, + 1mg/kg Ketamine IM
- Medetomidine (0.12-0.22mg/kg) + Ketamine (2.5mg/kg) + Butorphanol (0.05mg/kg) IM - 10 minutes to recumbency
- reverse with Atipamazole (0.25mg/kg) - 5 mins recovery
33
Vasectomy Procedure
- Make a 1 to 2 cm vertical incision in the scrotum, just proximal to the testicle
- Extend the incision through the skin and common vaginal tunic
- Incise the common vaginal tunic with care to prevent damage to the pampiniform plexus.
- free vas deferens from the common vaginal tunic and remove a 3 cm segment. Ligate each of the cut ends to help discourage recanalization. Leave the common vaginal tunic open.
- Close the skin with absorbable or nonabsorbable suture
- repeat the procedure on the other side
34
What are the DDx for penile/preputial swelling in bulls?
- penile haematoma
- ruptured urethra (diffuse ventral abdominal oedema)
- preputial laceration complex
35
Where and why do penile haematomas occur?
- occur at the distal sigmoid flexure
- caused by sudden bending of erect penis during service
- rupture arises from the dorsal or crural canal and tunica albuginea of the corpus cavernosum penis
36
What is the surgical treatment of penile haematoma?
- GA or sedate and lateral recumbency with local infiltration
- Tie upper hind leg up & back to expose the pre-scrotal area
- Incise over lateral aspect of prepuce for about 10-15 cm - through the skin and subcutaneous tissue – incise into haematoma and evacuate
- Once the clot is removed the rent in the tunica albuginea (usually on the dorsal surface of distal sigmoid flexure) is sutured with interrupted sutures of absorbable material
37
Medical treatment of a preputial prolapse/laceration
- sling - change daily
- cold hosing
- procaine penicillin
- Non-steroidals
- topical nitrofurazone or similar
38
What is the aetiology of penile deviations?
- dorsal penile ligament slips off side of penis
39
What are the two surgical techniques to reinforce the apical ligament for penile deviations?
1. apical ligament splitting and interweaving
| 2. fascia latae autografting
40
Structures passing through the inguinal canal?
- spermatic cord
- vaginal tunic
- cremaster muscle
- external pudendal artery and vein
- inguinal lymph vessels
- genitofemoral nerve
41
Structures passing through the vascular ring?
- testicular artery and vein
- lymphatics and nerves
- vas deferens
