general abdominal surgery in cattle, LDA

what type of sedaation / anesthesia is used for LDA

in most cases can be done standing:

xylazine + detomidine

xylazine-procaine epidural

ketamine is optional

high risk cases:

inhalation anesthesia

only in hospital environement

what should you see when you open the left flank?

rumen and nothing else

what should you see when you open the right flank?

mesoduodenum, duodenum, greater omental sling

what type of closure do you do in a large animal abdomen?

2-layer closure usually enough

3-layer closure in very large beef animals

simple interrupted or Ford interlocking

what spinal nerves need to be blocked in flank anesthesia?

T13, L1, L2

what is the inverted L approach for flank anesthesia?

local anesthetic away from surgical site

uses more local anesthetic but safe

what is a disadvantage of line block?

increased risk of skin sloughing

need to close with horizonal mattress

advantage of distal paravertebral block?

easy to perform

no spinal needles required

disadvantages of distal paravertebral block?

ataxia is major issue

not suitable for C-section

not suitable if risk of recumbency

how do you perform a flank anesthesia block?

subcutaneous injection on top, injecting in a fan shape about 15cm deep

how much should you clip around the incision?

20-30cm

what is the goal when opening for an LDA surgery?

identify the pylorus

the abomasum is located at the _______ of the right ventral abdomen

right midline

left abomasal displacement is when the abomasum moves ______ to _______

right to left

what are most LDAs associated with?

poor food intake post-calving

RDA is different (can occur anytime)

what do LDA patients usually concurrently have (and are thus risk factors for LDA)?

metritis

secondary ketosis

hypocalcemia (decreases food intake, causes bloat)

list some cow factors for LDA

dairy breeds

female

age >3 years (older cows higher risk)

periparturient period

large abdomen

high milk yield

twins

metritis/hypocalcemia/ketosis

what are some management factors for LDA?

inadequate diet (low fibre high energy, high fermentable carbs)

feeding practice (slug feeding, lack of transition feeding)

housing (lack of excercise, lack of feedspace, high stocking)

how is LDA diagnosed?

history and signalment (dairy cow recently calved, back in the milk and not eating)

clinical exam: pings

LDA will have pings under the last 3 ribs

empty rumen with large gas cap

don't need to do ballottement for LDA (more so with RDA)

selective inappetence suggests ______

ketosis

usually a secondary ketosis, so look for the primary issue (do the pings

what would you find on clinical exam of LDA?

pings under last 3 ribs

pneumoperitoneum or peritonitis

peritoneal abscess

no audible rumen contractions (because abomasum is in the way)

heart rate elevated but not signficantly

skin tent / sunken eyes

what do you use to differentiate dilation from volvulus?

heart rate

will be much higher in volvulus

how does the liptack test diagnose LDA?

Liptack test

aspirate fluid from area at ventral aspect of the pings, measure pH

abomasal pH should be close to 3 (anything less than 5)

this well tell you if the fluid you're pulling is from the abomasum or rumen

what would you see on serum biochemistry of LDA?

metabolic alkalosis

hypokalemia

hypochloremia

ketosis

why does LDA cause metabolic alkalosis?

chloride sequestered in abomasum

bicarb produced by kidneys raises to make up for this drop in chloride

bicarb sent to blood --> metabolic alkalosis

would you use fluid therapy post-op for LDA?

NO

contraindicated because of acid/base balance

what would be the conservative management of LDA? is it preferred?

Not preferred but still done

rolling- effective in 25% cases

cast into right recumbency, slowly roll dorsal, hold in dorsal for a few minutes, then roll to left lateral

use this method if there is time pressure, money pressure

would you use rolling for RDA?

NO- contraindicated

risk of inducing RVA

is LDA an emergency?

no

they lose BCS but do not die

surgery is more of a lactation-saving procedure rather than life-saving procedure

list the open surgical techniques for LDA

right flank omentopexy

right flank pyloroplexy

left flank abomasopexy

right paramedian abomasopexy

list the closed surgical techniques for LDA

closed toggle-pin fixation

2-step laparoscopic abomasopexy

1-step laparoscopic abomasopexy

advantages/disadvantages of right flank omentopexy for LDA?

very safe, can be re-done if something fails

high short term cure rate

1-person job, surgeon comfort

inability to visualise abomasal adhesions

demands advanced surgical skills

what is the most common surgical failure for right flank omentopexy in LDA?

tension due to incision placed too high and caudal

list the basic steps of right flank omentopexy in LDA

1. incise slightly caudal to last rib, arm-width

2. pull the pylorus out

3. deflate the abomasum, monitor gas release (do not rock it)

4. omentopexy, within 4 inches of the pylorus, 2 mattress stay sutures

advantages/disadvantages of pyloropexy instead of omentoplexy for LDA?

good for over-conditioned cattle or emaciated cattle when the omentum is friable

done when surgeon feels like omentopexy is not enough to hold abomasum in place

greater risk of pyloric stricture

advantages/disadvantages of left flank abomasopexy?

can be done on more chronic LDAs

surgeon can visualise ulcers and adhesions

preferred technique in advanced gestation

carries big risk of ulcer and fistula formation

risk of peritonitis

requires 2 operators for placing sutures

what is the preferred open surgical method for non-complicated LDA patients?

right flank omentopexy

advantages/disadvantages of right paramedian abomasopexy?

(cow is rolled into dorsal recumbency)

abomasum repositioned with minimal effort

maximum exploration of abdominal cavity

passive discharge of pathologic uterine contents

risk of bloat

more people required

risk of hemorrhage

risk of fistulas

how does the closed-toggle pin fixation technique work for LDA?

cow cast into dorsal recumbency

abomasum should rise

cow rocked until abomasum returns to right

first toggle inserted quickly so gas doesn't all escape

second toggle placed 3 inches caudal to first

tie the two ends together

advantages/disadvantages of closed toggle-pin fixation?

quick, cheap

high success- good lactation post op

risk of incarceration of bowel and/or realignment of abomasum

blind procedure

advantage/disadvantage of 2-step laparoscopic abomasopexy for LDA?

no abx needed

can visualise correct alignment

shorter surgery, faster recovery

low incidence of complications

requires special equiptment

cow must be case in dorsal for 2nd step, requires more people

advantage/disadvantage of 1-step laparoscopic abomasopexy?

done entirely in dorsal

risk of needle penetrating the rumen