LDAs, RDAs, and Volvulus (NOT FINISHED)

What is the most common indication for abdominal surgery in dairy cattle?

Altered abomasal function leading to displacement, especially LDA

Abomasal disease can be divided into what TWO categories?

1. Disorders involving abomasal outflow

2. Disorders altering abomasal wall integrity

What FOUR disorders alter abomasal outflow?

1. Displaced abomasum (LDA, RDA, AV)

2. Intraluminal obstruction

3. Abomasal wall lesions obstructing ingesta

4. Extraluminal masses obstructing ingesta

What TWO disorders alter abomasal wall integrity?

1. Abomasal ulcers

2. Abomasal lymphoma

True or False: Abomasal outflow disorders and wall integrity disorders are not mutually exclusive.

True!

What are the THREE categories of abomasal displacement?

1. LDA

2. RDA

3. AV

What is considered the prerequisite for abomasal displacement?

Abomasal hypomotility (atony)

What happens when abomasal motility decreases?

Gas accumulates -> distention -> abomasum "floats" in abdomen

Where is the normal position of the abomasum?

Ventral abdomen, slightly right of midline

Why is LDA more common than RDA?

Speculated influence of rumen size and positioning

What is the direction of most abomasal volvulus rotations?

Counterclockwise (viewed from top of cow)

True or False: RDA and AV can be distinguished based on the characteristics of their pings.

False! RDA and AV CANNOT be differentiated and all right-sided pings should be considered an emergency.

True or False: Dairy cows are much more likely to have an abomasal displacement than beef.

True!

What signalment is most at risk for LDA?

Adult dairy cows, early lactation

When do most LDAs occur post-partum?

Within 30 days of calving, usually in two weeks

What FOUR metabolic conditions predispose to LDA?

1. Hypocalcemia

2. Negative energy balance

3. Ketosis

4. Fatty liver

What THREE management factors contribute to LDA?

1. Improper dry cow ration

2. Transition diet mismanagement

3. Disrupted feed intake

Name at least THREE concurrent disease that increase LDA risk.

1. Metritis

2. Mastitis

3. Retained fetal membranes

4. Dystocia

5. Endotoxemia

True or False: Genetic factors like breed differences, motilin expression, and genes impacting calcium and insulin play a role in LDA development.

True!

Name the THREE classic presenting complaints of LDA.

1. Anorexia (usually grain first)

2. Drop in milk production

3. Ketosis (predisposing or result)

What manure changes occur with LDA?

Loose, pasty, reduced volume

What is the hallmark exam finding of LDA?

What does it sound like?

Left-sided ping over last few ribs

Pennies in a well or basketball on concrete

True or False: Rumination is still likely occurring in LDA, but involves a reduced fill where the last few ribs are often sprung.

True!

When pinging the side of a cow, draw a football between the —————- and the ————— and ping the entire space.

Point of elbow

Tuber coxae

Name FOUR differentials for a left-sided ping.

1. Ruminal tympany

2. Collapsed rumen

3. Pneumoperitoneum

4. Gas-containing abscess

What test involves percutaneous abomasal sampling of pH?

What pH confirms abomasum?

What unique smell does it have?

Liptak test

<3.5-4.5 (lower since the true stomach)

Burnt almonds/slightly acrid

What TWO major ultrasound findings are true of LDA?

1. Pylorus not living where it should

2. Fluid filled viscus that looks different from normal rumen wall

What THREE major acid-base changes are seen with LDA?

1. Metabolic alkalosis

2. Hypochloremia

3. Mild increase in HCO3

—- might occur in LDA with shifts in H-K due to acid-base and —-/—- due to reduced feed intake.

Hypokalemia

Hypocalcemia/hypophosphatemia

What unusual urinary finding occurs with LDA?

Paradoxical aciduria

What result might you expect to see from LDAs with concurrent ketosis and degree of fatty liver, in which all DAs should be tested?

Increased liver enzymes

What is the goal of surgical correction of LDA?

What are the TWO common options/targets?

Create a pexy to prevent recurrence

1. Greater omentum

2. Abomasum (greater curvature; pylorus)

What blind technique is used for LDAs?

What are the names of the surgical techniques?

Roll and toggle

Omentopexy, Pyloropexy, Abomasopexy

Why is rolling alone rarely recommended?

High recurrence rate

Explain what a roll and toggle is.

Blind abomasopexy performed in dorsal recumbency.

Name FIVE advantages to a roll and toggle.

1. Short procedure (<15 minutes)

2. Minimal invasion of peritoneal cavity

3. Minimal equipment

4. Do not usually have to withhold feed or water

5. Economics

Name SIX disadvantages to a roll and toggle.

1. Inability to confirm return of abomasum to normal position

2. Tack wrong viscus

3. NOT used for right-sided pings

4. Abomasum needs to be freely moveable (no adhesions/path)

5. Cannot assess abdomen for abnormalities

6. Labor intensive and risk to handlers

When should toggle sutures be cut?

What happens if they are left too long?

2-3 weeks post-op

Increased risk of fistula

Name THREE complications of a roll and toggle.

1. Peritonitis

2. Fistula formation

3. Thrombosis and cellulitis (don't hit a milk vein you idiot)

True or False: The standing right flank approach to an LDA is more thorough of an explore compared to left or paramedian.

True!

Explain the right flank approach to a LDA.

Block the right paralumbar fossa -> cut into -> deflate abomasum -> bring it under rumen and back to normal position -> bring pylorus up to incision and pexy

Name at least FOUR tricks to getting the abomasum back to where it should be.

1. IV simplex tubing and teat cannula/large needle

2. Make sure don't lose needle

3. Protect needle in palm on way in

4. Avoid omental sling- go south first, then north

5. Faster with a vacuum pump

6. Poke it once at highest point and push down steady pressure

What is the best way to push the abomasum under the rumen?

Lay forearm and left palm on top of it and do "breast strokes"

Name FIVE ways/landmarks to make sure you are headed in the right direction when fixing a displaced abomasum from a standing right sided approach.

1. Grab a handful of greater omentum

2. Hand over hand, slow and steady traction

3. Identify "sow's ear" in the omentum

4. Identify pylorus (always palpable; potentially visualized)

5. Palpate abomasal wall and proper position of omasum

What are the FOUR keys to a stable omentopexy?

1. Choose site as close as possible to normal position of the pyloroduodenal juncture without interfering with duodenal function

2. Distribute pexy over as wide an area of omentum as possible

3. Incorporate peritoneum in the pexy

4. Use a suture that will last long enough for firm fibrous adhesion to form

What kind of suture is best for an omentopexy?

2 or 3 monofilament nonabsorbable (i.e. 2 PDS)

Describe how you would pexy the omentum in an omentopexy.

Hang the omentum like a curtain and incorporate into your first layer of closure (peritoneum and transversus abdominus) with a simple continuous pattern with generous bites through the omentum

True or False: A pyloropexy can be performed alone or in combo with an omentopexy.

True!

What structure should you make sure that you are not too close to in a pyloropexy?

Pyloric sphincter (exit)

You should be at least 5 cm (orad/aborad) to the exit within the —— of the pyloric sphincter, or what might happen?

Oral

Antrum

Risk of stenosis or goose-necking twists

Describe how to perform a pyloropexy.

Use 2 or 3 suture with a horizontal mattress pattern a few inches cranial to your incision. Cut through the TA and IAO and start on the outside of the muscle into the abdomen and partial thickness of the pylorus. Then, come back out through the muscle and tie a knot on the outside of the muscle.

Name THREE disadvantages to a left sided standing abomasopexy.

1. Poor access to the rest of the abomasum for exploration

2. Not indicated for right displacements/volvulus

3. Surgeon requires long enough reach (assistant needed)

Slide 27

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