Abomasal Disorders: RDA

Question 1

How to determine RDA

Answer 1

Same as LDA except ping on right
DDx = cecal dilatation
Keep pinging to see how far back it goes

Question 2

RDA with volvulus

Answer 2

Dilatation -> caudal and dorsal displacement
Counterclockwise rotation
- Can involve omasum; worse prognosis
Complete obstruction
- Accumulate fluid
. increased fluid leads to poorer prognosis

Question 3

RDA History

Answer 3

Early lactation
Acutely off feed
Dramatic decrease in milk production

Question 4

RDA presentation

Answer 4

Exam:
Depressed
Dehydrated
Ping on R.
Tachycardia >100 = immediate Sx

Serum chem:
Decreased K
Decreased Cl <80 poorer prognosis
Metabolic alkalosis

Question 5

RDA Tx

Answer 5

Sx: R flamk laparotomy

• Deflate: gas and fluid
• Correct torsion
• Omentopexy

Supportive cars
- Fluids
 . Oral for mild to moderate
 . IV for severe
- Transfaunate
- Flunixin
- Abx

Question 6

RDA Outcome

Answer 6

65-85% survival
- Poor prognostic indicators: large volume of fluid in abomasum, [Cl] <80, discolored serosa (vascular compromise)
Complications
- Loss of abomasal motility: 5-10% of cases
- Ulcers: necrosis of mucosa
- Peritonitis: ischemic necrosis of wall of abomasum

Question 7

Abomasal impaction basics

Answer 7

Beef cattle and sheep - pregnant
Winter
- Stored feeds or graze crop residue
- Increased maintenance energy requirement
 . Increased feed consumption
Sporadic in dairy cattle

Question 8

Abomasal impaction etiology

Answer 8

Diet (be aware of defect in sheep)
- Poor quality forage (low digestibility)
 . Chopped forages increase passage rate
- Sand
 . Pica
 . Sand laden feeds
  - Root crops
  - Hay fed on ground (sandy soils)
Rumen motility disorders
- Vagal indigestion
- Hardware disease
Pyloric obstruction/dysfunction
- Lymphosarcoma
- Vagal indigestion

Question 9

Mechanism for Abomasal Impaction

Answer 9

Initiating factors unknown
Decreased motility
Decreased outflow
Accumulation of feed

Question 10

Abomasal Impaction Hx

Answer 10

Decreased appetite
Weight loss
Reduced milk production
Weakness or lethargy
Bloat

Question 11

Abomasal Impaction CS

Answer 11

TPR normal: increased HR in advanced cases
Abdominal distension
Rumen over-filled with ingesta
- Bloat vs. distension
Decreased rumen contraction

Question 12

Abomasal Impaction Clin path

Answer 12

Serum chem:
Decreased Cl
Decreased K
Increased HCO3

Rumen fluid:
[Cl] >30mmol/L

Question 13

Abomasal Impaction Tx

Answer 13

Oral fluids and mineral oil
IV fluids prn
Prokinetic drugs
- Macrolide abx
 . Erythromycin lactobionate
Sx if no response to medical tx
- R paramedian
- Abomasotomy and empty contents
 . lg volume
 . firmly packed

Question 14

Abomasal Impaction Prognosis

Answer 14

Mild cases: good
- Dx is presumptive
Moderate cases: fair to guarded
Severe: poor
- HR >100, [Cl] <80, significant ruminal distension
- Slaughter or euthanasia