Indigestion in Ruminants 1

Question 1

Types of primary indigestion, broadly

Answer 1

• Reticuloruminal Motor Disorders or Diseases
  of the Rumen Wall
• Reticuloruminal Fermentative (Microbial and Biochemical) Disorders

Question 2

Reticuloruminal Motor Disorders or Diseases
of the Rumen Wall
- 4 common ones

Answer 2

• Obstructive (vagal) indigestion (failure of omasal transport, failure of pyloric outflow, and free gas bloat)
• Obstruction of the cardia
• Obstruction of the reticuloomasal orifice
• Diaphragmatic hernia

Question 3

Reticuloruminal Fermentative (Microbial and Biochemical) Disorders
- 6 common ones

Answer 3

• Inactivity of rumen microbial flora (caused by poor- quality roughage that leads to rumen impaction)
• Simple indigestion
• Acute ruminal lactic acidosis
• Subacute ruminal acidosis (SARA)
• Rumen alkalosis
• Putrefaction of rumen ingesta

Question 4

Secondary Indigestion broad categories

Answer 4

• Secondary reticuloruminal motor inactivity
• Secondary reticuloruminal microflora inactivity
• Abomasal reflux

Question 5

normal ruminal fluid color, consistency, and odor, pH, gram stain of bacteria, chloride concentration

Answer 5

colour: olive, brownish-green
consistency: slightly viscous
odor: aromatic, strong
pH: 6-7 on roughage, 5 - 6.5 on grains
> generally want at least 6.5
gram stain: predominant gram-negative
Chloride: <30 mEq/L
> important for checking internal vomiting
> Mema says maybe more like 25 mEq/L

Question 6

is indigestion more common in heavily or lightly fed cows?

Answer 6

common in heavily fed cows

Question 7

what is considered indigestible roughage, that can contribute to indigestion?

Answer 7

■ Low in protein
■ Moldy
■ Overheated
■ Frosted

Question 8

what types of diets can contribute to indigestion?

Answer 8

■ Dietary abnormalities
■ Indigestible roughage
■ Excesses of grain and concentrate
■ Sudden change in grain
> from oat to what or barley
■ Straw
■ Bedding or scrub fed during drought periods
■ Good quality ensilage (if unlimited access)
■ Depraved appetite

Question 9

what change in water intake can contribute to indigestion?

Answer 9

■ Limited drinking water

Question 10

pathogenesis of how dietary abnormalities can cause indigestion? number one thing we notice?

Answer 10

dietary abnormalities > primary atony
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we dont hear any sounds

Question 11

pathogenesis of how different pH foods can cause indigestion

Answer 11

Grain (low pH) + high protein diets (high pH)
> atony
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We dont hear any sounds

Question 12

clinical findings of indigestion

Answer 12

■ Decreased appetite
■ Mild drop in milk production
■ Anorexia
■ Dullness (mild)
■ No rumination
■ Ruminal movements:
> Depressed in frequency and amplitude
> Absent in some cases
■ Rumen may be larger
■ Tympany
■ More common: firm, doughy without distention
■ Reduced fecal output/dry feces
■ Progress to diarrhea: voluminous/mal odorous

Question 13

clinical tests for rumen fluid with indigestion

Answer 13

■ Intestinal microbiota
■ Sediment activity test
■ Cellulose digestion test
■ pH (6.5-7.0 normal)

Question 14

urine sign from indigestion?

Answer 14

ketone bodies

Question 15

differential diagnosis for indigestion

Answer 15

■ Acetonemia
■ TRP
■ Grainoverload
■ LDA
■ Right-side dilation of abomasum
■ Abomasal volvulus
■ Vagal indigestion
■ Phytobezoars
■ Systemic diseases: Septisemia/toxemia, hypocalcemia, anaphylactic reactions

Question 16

treatment options for indigestion

Answer 16

■ Spontaneous recovery: No treatment
■ Rumen lavage
■ Rumenatorics
> Nux vomica, ginger, tartar emetic: ?
■ Parasympathomimetics
> Carbamylcholine, physostigmine, neostigmine
■ Alkalinazing and Acidifying agents
> Magnesium hydroxide
> Acetic acid / vinager (5-10L)
■ Re-establishing of the ruminal microflora
> Transfaunation

Question 17

what is Obstructive indigestion syndrome (vagal indigestion, Hoflund’s syndrome):

Answer 17

■ a group of motor disturbances that hinder passage of ingesta out of the reticulorumen or abomasum or both
■ It is a syndrome, meaning a constellation of signs of disease, but with diverse potential causes
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This syndrome must be thought of as a complex or set of signs secondary to a primary lesion at some point along the course of the vagus nerve - but sometimes damage to vagal nerve is not clear, or maybe not present?…….

Question 18

etiology of vagal indigestion / obstructive indigestion syndrome? what are the 4 categories of things that can cause it?

Answer 18

Outflow Disorders:
■ Extra-luminal causes
> Adhesions, abscesses, distortion of esophageal groove

■ Intra-luminal causes
> Foreign bodies (placenta), straw

■ Intra-mural causes
> Neoplasia, inflammatory abscesses, granulomas

■ Neurogenic lesions
> Adhesions
> Lesions affecting tension receptors in medial wall of reticulum

Question 19

connection of liver abscessation to cessation of transport of digesta through the omasum? clinical signs?

Answer 19

• Clinical signs: abdominal distention and bradycardia
• Medical therapy had not been effective
  > vagal indigestion resulting from liver abscessation in dairy cows

Question 20

perireticular abscess connection to failure of omasal transport? clinical signs?

Answer 20

■ Anorexia, hypogalactia, and bilateral abdominal distention.
- Traumatic reticulo peritonitis was believed to be the cause
> vagal indigestion

Question 21

differential diagnosis in cattle with a chronic inflammatory process, cranial peritonitis, or vagal indigestion? how to solve?

Answer 21

• Liver abscesses
• Prolonged treatment with antimicrobials might be successful.

Question 22

traumatic reticlupoeritonitis - common causes? how it can result in vagal indigestion?

Answer 22

• controversial
• cows eat eg. metals, cause:
  > vagal nerve injury
  > reticular adhesions
  > other?

> > vagal indigestion

Question 23

why has the vagal nerve injury theory for ‘vagal indigestion’ been disputed?

Answer 23

■ Cases of vagal indigestion may have extensive adhesions between reticulum and adjacent organs:
■ But:
■ Little evidence of nerve injury
■ May occur in cases with no evidence of serosa inflammation

Question 24

Naturally occurring syndrome = to Hoflund’s syndrome (vagus nerve sectioning)
- how is this related to anterior and posterior stenosis?

Answer 24

■ Anterior Stenosis (achalasia of the reticulo-omasal orifice)
> No passage of ingesta from reticulo-rumen to omasum- abomasum
> Dorsal vagal nerve branch injury
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■ Posterior stenosis (achalasia of the pylorus)
> Inhibition of abomasum flow (resulting in impaction)
> Ventral vagal nerve branch injury

Question 25

probably the most important cause of ‘vagal indigestion’

Answer 25

• Mechanical impartment of reticular motility and esophageal groove dysfunction
  > Disturbance of particle-separation process (2nd to TRP)

Question 26

Mechanical impartment of reticular motility and esophageal groove dysfunction
- this is an important cause of vagal indigestion
- is there evidence of corresponding nerve damage? what can cause the disease?

Answer 26

• No histological evidence of nerve damage
• Peri-reticular abscesses near the reticulo-omasal orifice can cause the disease

Question 27

4 less common causes of ‘vagal indigestion’

Answer 27

■ Actinobacillosis of rumen and reticulum
■ Fibropapiloma of the cardia
> Mechanical obstruction of the esophagus
■ Pyloricachalasia
■ Indigestion of late pregnancy

Question 28

in what cows is vagal indigestion common?

Answer 28

• common in cows with history of traumatic reticuloperitonitis
• Also occur in beef cows and mature bulls

Question 29

clinical signs of vagal indigestion / obstruction?

Answer 29

Vague” signs:
■ Slow loss of production
■ Slow weight loss
■ Poor appetite
■ Scant, pasty feces
■ Abdominal enlargement - “papple” shape
■ Rumen hyper motility
■ Bradycardia

Question 30

Clinical signs Omasal transport failure
- rumen appearance and contractions? fecal output? possible sequelae?

Answer 30

■ Inappetance with distention of the rumen (left flank)
■ Rumen assume an L-shape (papple shape)
■ Reduced fecal output
■ Rumen still contract in most cases/some have complete atony
■ No stratification → leads to frothy bloat

Question 31

Vagal paralysis may affect ingesta flow into the omasum by two mechanisms:

Answer 31

■ Paralyzed or relaxed esophageal groove blocks flow into the omasum
■ Lack of pumping action of the omasum to draw fluid through the reticulo-omasal orifice

Question 32

Clinical signs Pyloric outflow failure
- where do we see distension?
- stratification of ingesta? what is going on in the forestomachs?
- fecal output?
- other metabolic conditions?

Answer 32

■ Advance cases will present reticulo-rumen distention
■ Motility of forestomachs is not markedly affected → stratification of ingesta is maintained
■ Overfilling of the forestomachs can occur due to abomasal reflux (internal vomiting)
■ Dehydration, hypochloremic metabolic alkalosis
■ Decreased fecal output

Question 33

what part of the body will bulge in vagal indigestion vs abomasal impaction?

Answer 33

vagal indigestion - bulge around the whole body except top right
abomasal impaction - bulge in bottom right only

Question 34

what will we wee on a hemogram for traumatic reticloperitonitis? biochem? another sign that could indicate?

Answer 34

hemogram: neutrophilia, with left shift and monocytosis
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Biochem: Metabolic hypochloremia, hypokalemic alkalosis (abomasal impactions)
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Peritoneal fluid

Question 35

Rumen chloride concentrations
- what is normal?
- what indicates posterior stenosis?
- what indicates indigestion of late pregnancy?

Answer 35

■ <30 mmol/L (normal)
■ >40 mmol/L (posterior stenosis)
■ 66 mmol/L (indigestion of late pregnancy)

Question 36

how do we treat vagal indigestion?

Answer 36

■ Rumen lavage
■ Rumenotomy to remove contents
■ Treat reticular abscesses/adhesions
■ Lymphosarcoma (no Tx)