Abomasal Displacement & Volvulus Sx

Question 1

what is the most common abomasal displacement?

Answer 1

LDA

Question 2

“LDA is a management disease” what does this mean?

Answer 2

that well managed cows should not be getting this

Question 3

when do cows tend to get LDAs?

Answer 3

after calving: due to the incidence of many other diseases during this time, some cows are vaccinated at this time, hows come back into estrus and dont eat, etc. many contributing factors

Question 4

there are like a million risk factors for LDAs. Queen all you have to do is name a few. it’s okay.

Answer 4

being a holstein cow with a large abdominal cavity, being older (multiparous), change in diet, decreased exercise, high concentrate feeds, hypocalcemia, ketosis, retained placenta, metritis, mastitis, endotoxemia

Question 5

4 steps of general pathogenesis for displaced abomasum

Answer 5

small rumen (not eating), abomasal atony, gas production, displaced abomasum

Question 6

what metabolic derangement does an LDA/RDA cause?

Answer 6

metabolic alkalosis (all acid sequestered in abomasum)

Question 7

with an RTA, describe how the abomasum turns out of place

Answer 7

twists counter clockwise when viewed from behind and an additional counter clockwise twist when viewed from above

Question 8

why is an RTA so much worse than a LDA/RDA?

Answer 8

RTAs result in a complete pyloric outflow obstruction and vascular compromise, potential tissue devitalization (weaken or debilitate)

Question 9

true or false: a cow with signs of colic is okay to wait until morning, and usually recovers on their own with medical management

Answer 9

FALSE!!!!! cows with signs of colic can NOT wait until morning and usually require surgical intervention!!!

Question 10

when you are doing a distant exam on a cow you suspect has an LDA or RDA/RTA, what sorts of things are you looking for (esp in differentiating between a displacement and a torsion). There are a lot of these queen so it’s okay if you dont list them all

Answer 10

• are they dull/depressed/shocky–>torsions will be more shocky
• how dehydrated are they? more severe with a torsion
• are they eating? more likely to not eat with a torsion
• is the cow chewing cud? less likely to with a torsion
• are there signs of colic?
• what is the abdominal contour? L or R side look enlarged?
• resp rate–>would be higher with a torsion
• check the records like if they have a rumen activity sensor or check milk production

Question 11

after your distant exam on the cow, you want to do your actual PE. If you suspect an LDA/RDA/RTA, what sorts of things are you looking for?

Answer 11

• a high HR, the higher it is the more likely it is a torsion
• rumenation/rumen rate: probably still present with just a displacement, but may be harder to hear with an LDA since rumen is behind the gas distended abomasum. with RTAs there will be no rumination
• CBC/chem would see met alk hypochloremia and hypokalemia

Question 12

C/S of an LDA

Answer 12

decreased appetite, decreased rumen motility, decreased milk production, ketosis, rumen contractions hard to hear

Question 13

a boring person named Boring Person brings you his cow named Boring Cow. Boring Cow is eating less feed, not producing as much milk, and when you try to listen to rumen contractions they are very hard to hear. Top differential?

Answer 13

LDA

Question 14

Boring Person has another cow named Sleepy Cow, who is not eating, is not producing feces, has sunken eyes, has a HR of 100, has weak pulses, has no signs of any ruminal contractions, and has bilateral abdominal distention. When you listen you can hear a ping on the R side. Top differential?

Answer 14

RTA (or RDA)

Question 15

general bloodwork findings you’ll see with an LDA

Answer 15

met alk: high pH, high bicarb, low Cl and K, hypoglycemia, ketonemia, +/- stress leukogram

Question 16

general bloodwork findings you’ll see with RDA/RTA

Answer 16

hypovolemia, dehydration, hemoconcentration, hyperglycemia, met alk, hypocalcemia, hypochloremia, hypokalemia, hyponatremia, paradoxic aciduria

Question 17

what abnormalities will you find on your PE with an LDA/RDA/RTA?

Answer 17

the PING on percussion

in the case of a torsion, might have a positive succusion

Question 18

can you feel a DA on rectal palpation?

Answer 18

only if its really big but usually not

Question 19

how do you differentiate between an RDA and a RTA?

Answer 19

signs of shock=more likely to be a torsion

Question 20

why do we do a rectal exam last?

Answer 20

dont want to introduce a pneumorectum–>can result in a false PING

Question 21

what else besides pneumorectum can cause a false ping?

Answer 21

a gas filled rumen–>can feel this on rectal palpation

Question 22

what are some differentials for an LDA/RDA/RTA?

Answer 22

ruminal tympany/bloat, pneumoperitoneum, cecal distention, gas in spiral colon, pneumoperitoneum, metritis where there’s gas in the uterus from gas proeucing bacteria

Question 23

in addition to PE findings, what are some diagnostics you can do to confirm an LDA/RDA/RTA?

Answer 23

• BHBA test–>we know that any paripartueitn disease can be associated with DAs so if the cow has high ketones, more likely to also have a DA
• stall side calcium tests (iSTAT, Horbia)
• blood lactate: good prognosticator for acute abdomen in any animal

Question 24

when making your incision for the right sided approach surgery, where are your landmarks?

Answer 24

one hand down from transverse processes and a few inches caudal to 13th rib

Question 25

what layers are you cutting through in order when making your incision in the R paralumbar fossa? for each of these layers, what is the ideal surgical way to get through them?

Answer 25

skin, external abdominal oblique, internal abdominal oblique, transversus abdominus, peritoneum

skin & external ab ob: sharp dissection
int ab ob & transversus: blunt dissection OR CAREFUL sharp
transversus & peritoneum: blunt dissection

Question 26

briefly describe how you do the R sided approach to fix an LDA

Answer 26

• start with a quick exploratory, look for ahesions and palpate the liver and the omasum
  -then move around to the caudal abdomen with your left hand and pass around the caudal dorsal rumen until you can feel the body wall, then move forward until you can feel the rumen
• once you can feel the rumen, you need to deflate the air either passively or actively with suction
• then you can gently push the abomasum under the rumen back to the right side
• can also pull the omentum up at a 45 degree angle until you pull the rumen under the abomasum
• reduction is completed when you can see the pyloric antrum at the incision site
• perform a pexy and close

Question 27

pros and cons of a right sided flank approach

Answer 27

• can be done standing, can be done without assistance, can do an abdominal explore first, can fix LDA, RDA, and RTAs
• can be difficult during late pregnancy
• adhesions are harder to visualize and navigate

Question 28

how to tell between an RDA and RTA when going in for surgery

Answer 28

after making your incision, identify the gas filled abomasum just cranial to the incision and move your hand down the medial side of the abomasum–>if you can run your hand down the medial aspect of the abomasum until you reach the body wall, it is just displaced

Question 29

briefly describe how you do the R sided approach to fix an RDA

Answer 29

after feeling the abomasum along the medial aspect, the abomasum now needs to be drained/deflated using a large bore attachhed to a sterile tube or pump
-after it’s been pumped, the left hand pushes the top of the abomasum down to correct the CCW twist, then you can pull the omentum at a 45 degree angle until you can see the pyloric antrum at the incision site, pexy and close

Question 30

briefly describe how you do the R sided approach to fix an RTA

Answer 30

after trying to run your hand down the medial aspect of the abomasum and being unseccessful, you still need to deflate it with a large bore and a sterile tube or pump
- after it’s been drained, you correct the CCW twist as seen from above by turning in CW direction, then correct the CCW twist as seen from behind
- pull omentum at 45 degree angle until can see pyloric antrum at incision site
- pexy and close

Question 31

what is an omental pexy and why would you chose it over an abmasal pexy?

Answer 31

2 horizontal mattress sutures in the greater ometum and then anchored to the transversus abdominum, then the omentum is incorporated in the closure of the T abdominus

• can’t cause a pyloric outlofw obstruction this way, but these sutures can very easily rip out and tear

Question 32

how does one do a pyloro/antro pexy?

Answer 32

horizontal matress sutures in the pyloric antrum, a bit proximal to the pylorus, dont do full thickness bites, can incorporate omentum into closure of T abdominus

better for fat cattle where fat is friable

Question 33

describe what a toggle suture is and when you use it

Answer 33

an LDA procedure only, can cause volvulus in a cow with RDA

rolling the cow will make the abomasum float to the ventral abdomen–> cast her to the R ride and rol her CW as viewed from the rear–> few inches behind xiphoid and a few inches to the right is prepped–>identify where abomasum by percussing, then trocar is placed over the ping caudal to xiphoid and medial to midline. please see slides for more info I can’t write

Question 34

pros and cons of doing toggle procedure

Answer 34

pros: cheaper, quicker, less prep, if successful it is faster recover and less peritonitis and less muscle trauma

cons: blind technique, sutures can rip out and cause severe peritonitis, if there are adhesions you wont be successful

Question 35

what happens if you just roll the cow and don’t actually toggle the abomasum?

Answer 35

rolling along results in 70% reoccurance so usually not done

Question 36

if the cows HR is 100bpm or higher what does this tell you?

Answer 36

this is a bad prognostic indicator–>56% salvaged, euthanized, or died