Displaced Abomasum Flashcards
When does DA occur?
when the abomasum moves from normal ventral position to a position located more dorsally in the abdomen
Is LDA or RDA more common? Which one is more likely to involve torsion?
LDA more common
RDA more likely for torsion
Why is abomasal atony or decreased muscular contraction problematic?
-atonic abomasums are prone to gas distention as a result of increased fermentation of ingesta arriving in the abomasum and promoting increased VFAs and gas production
How does DA effect the body?
- Metabolic Alkalosis –> normal passage of ingesta and secretions into SI can’t occur easily –> HCl gets sequestered in lumen of abomasum –> diminished amount of circulating acid in blood
- Hypokalemia –> metabolic alkalosis promotes potassium to leave circulation and enter cells
- Hypoglycemia and ketonuria –> unknown reasons
Clinical signs of LDA
- partially to completely off feed
- decreased weight gain or production
- decreased/absence of feces
- mild to moderate dehydration
- abdominal distention around last rib or two
- increased resonance discovered upon abdominal auscultation and percussion over area where the gas-filled abomasum has displaced
Clinical signs of RDA
- complete obstruction of passage of ingesta
- severe dehydration
- tachycardia secondary to circulatory shock and pain
- weak and thready pulse
- severe abdominal distention secondary to gas accumulation within the abomasum
Conditions that predispose a ruminant to DA
- Dietary –> any alteration in diet or feeding pattern or the feeding of a high concentrate diet with minimal roughages
- Concurrent Dz
What are some concurrent Dz that predispose ruminants to DA?
Dz that result in development of endotoxemia or pyrexia
ie) metritis, mastitis, pleuropneumonia
How do endotoxins contribute to DA?
directly inhibit abomasal contractions or indirectly inhibit abomasal motility –> promote presence of hypocalcemia –> lack of Ca reduces muscle contractions of the abomasum –> atony and gas accumulation
Who’s at greatest risk for DA?
- Diary cows early in lactation due to change in diet to higher concentrates to promote milk production
- hypocalcemia (milk fever) due to inhibition of abomasal activity
- any cow with systemic Dz
What is the nonsurgical DA treatment? What are it’s cons?
-Involves rolling affected patient to promote movement of abomasum back to normal ventral location
Cons:
- temporary fix; almost always reoccurs
- can only be implemented in LDA
What is the goal of surgical DA Tx?
to replace the abomasum in correct location via tacking it to the abdominal wall
How can DA be prevented?
- slow transition of dairy cows to high concentrate diets to help acclimate the GI tract
- give roughages that are large enough in particle size
- reduce incidence of concurrent inflammatory Dz and hypocalcemia
