Omasal And Abomasal Disorders

Question 1

What is the normal location of the omasum?

Answer 1

Right of the median plane and opposing the 7th and 11th ribs

Question 2

What is the function of the omasum?

Answer 2

Provides large surface area for absorption of..
volatile fatty acids
Electrolyte
Water

Reduce feed particles

Question 3

What are clinical signs of omasal impaction?

Answer 3

Anorexia 
Dehydration 
Abdominal distention 
Ruminal hypomotility 
No palpable abnormalities of intestines 
Empty rectum (no feces)

Question 4

Causes of omasal impaction?

Answer 4

Feeding of rough fibrous feed during droughts or feeding machine-made wheat

Question 5

What are risk factors for abomasum?

Answer 5

Stress factors

• > higher stocking rate
• > parturition (retained fetal membranes, mastitis, Metritis, hypocalcemia)

Question 6

What bacteria are assoicated with abomasal ulcers?

Answer 6

H pylori 
Clostridum perfringens type A 
Campylobacter 
Strep 
Fungi

Question 7

What type of ulcer occurs during the periparturient period and. What other conditons can it be associated with?

Answer 7

Type I

LDA
Coliform mastitis
Metritis

Question 8

Clinical signs of a type I ulcer?

Answer 8

Not severely after 
Reduced feed intake 
Reduced milk production 
Darkened, soft to fluid feces 
Minimal anemia

Question 9

What type of abomasal ulcer is associated with lymphosarcoma but can occur in any stage of lactation or gestation?

Answer 9

Type II

Question 10

Clincial signs of a type II abomasal ulcer

Answer 10

Black tarry feces 
Anemia 
Sharp decline in milk production 
Depression 
Depressed rumen motility

Question 11

What type of abomasal ulcer is associated with early postpartum and can resemble a TRP cow?

Answer 11

Type III

Question 12

Clinical signs of a type III abomasal ulcer?

Answer 12

Moderate febrile
Anorexic
Acute decreased milk production

perforating

Question 13

Clinical signs of a type IV abomasal ulcer

Answer 13

Tachycardia

Complete rumen stasis
Severe dehydration
Recumbency with cold extremities

perforating

Question 14

What diagnostics can you do to detect type I and type II abomasal ulcers?

Answer 14

Anemia (PCV <15%)

Fecal occult blood test — detects 75ml blood loss/day

Question 15

What is the treatment for a type I or type II abomasal ulcer?

Answer 15

Correct concurrent dz
Reduce stress
Correct diet

Severe anemia —> restore blood vol

• IV fluids
• whole blood (5L minimum recommended), no cross matching neede

Question 16

What diagnostics can you do if you suspect a type III or type IV abomasal ulcer?

Answer 16

Abdominocentesis

Toxic changes in cells + intracellular bacteria

Question 17

T/F: the majority of displaced abomasums are the the right

Answer 17

False

Left (90%)

Question 18

How does a left displaced abomasum usually appear?

Answer 18

180 degree torsion without volvulus
Rotation along its long axis ventral and to the left of the rumen

Little to no outflow obstruction occurs

Question 19

How does a right displaced abomasum usually appear?

Answer 19

180 degree torsion +/- volvulus
Rotation around the mesenteric axis
Outflow obstruction AND ischemia of gastric arteries

Question 20

What are risk factors for displaced abomasum?

Answer 20

Genetics
4-7year old dairy cows
Periparturient dz

Liver disease 
Ketosis 
Hypocalcemia 
Ineffective fiber 
Metritis 
Mastitis 
Dystocia

Question 21

What diagnostics can you do for suspected displaced abomasum?

Answer 21

Auscultation “ping”
Ph analysis
Liptack test —> abomasal centesis (take sample from just below the ‘ping’)
Abomasal fluid pH < 4.5 and has a burnt almond odor

Abdominal US or exploratory

Question 22

Treatment for displaced abomasum?

Answer 22

Correct underlying dz

Surgical