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Rumenoreticular Dz

sihirlifil's version from 2018-08-31 23:30

Rumen: Function disorders

Question Answer
Rumen diseases: disorders of FUNCTIONRumen bloat
Rumen drinking
Vagal indigestion
2 types of bloat?Free gas
Free gas bloat occurs becauseEructation fails (representative of some other underlying dz)
Frothy bloat occurs becauseAssociated with feed
Free gas bloat: primarily in WHO?Recurrent problem in individual animals on a high grain diet
Possible reasons for free gas bloat(eructation/rumen outflow failure) Esophageal obstruction, cardia obstruction (extramural e.g. LN), motor dysfxn (hypocalcemia, vagal indigestion), chemical inhibition (microbial fermentation disorders)
CS of free gas bloatMarked abdominal distention
Rumen ping, decr contractions
Inc HR, RR (shallow b/c compresses diaphragm)
Anal & vaginal prolapse, tail elevation
Collapse, death
Tx of free gas bloatPass a tube! deflates nicely
Correct underlying problem: Hypocalcemia, TRP
Temporary rumen fistula, if necessary (severe depressed, cant pass tube, not sure of obstructed)
What's wrong with this guy? how was he treated?
Free gas bloat (2ry to pneumonia): gas cap on left, ping
Passed orogastric tube
Pathophys of frothy bloatFeeding of lush pasture (legumes e.g. clover, alfalfa): high in chloroplast mb fragments & soluble protein (makes foam suspended in liquid). Concentrate diet high in protein --> production of stable foam that traps gas --> Blocks cardia & prevents eructation
CS of frothy bloatSimilar to free gas but NO AUSCULTABLE PING despite marked L flank distention (not big free gas area, just foamy bubbles, so no interface)
What kinds of stuff would you give for frothy bloat?Reduce surface tension: destabilize bubbles & allows gas to be eructated
Poloxalene (destablilzes bubbles
((dioctyl sodium sulfate not so much anymore)

Vetetable oil, mineral oil
How else can you treat bloat (besides destabilizing bubbles)Rumenostomy (avoid unless necessary or if bloat is recurrant)
Prevention of frothy bloatSlow adaptation to grain/legumes
Avoid pastures with >50% legume content
Poloxalene in feed
Effective fiber! dry grass hay, nonlegume
Pre-feed ionophore antibx
ACUTE bloat in calves: when does it happen?Following milk or replacers (rapid change
CHRONIC bloat in calves: when does it happen?OLDER (weanling) calves fed low-fiber diet
Following severe bronchopneumonia: dmg to thoracic vagus nerve or tracheobronchail lymphadenopathy
What is Reticuloruminal milk accumulation?Aka "rumen drinking," esophageal groove not closing, milk ends up in rumen instead of bypassing like its supposed to
How does reticuloruminal milk accum happen?Overfeeding (milk backs up)
Calves gulping, not suckling (competition etc)
CS of rumen drinkingMilk ferments in rumen & is putrified
Recurrent bloat occurs
VFAs lead to acidosis --> pasty feces (adults set up for this but calves papillae not developed enough), calves crave fiber pathologically (start grooming, get trichobezoars). Growth rate is reduced
If you see this little guy with this in his rumen, what you thinking?
Rumen drinking (esoph groove fails to close)
Tx of rumen drinkingRelieve bloat with orogastric tube
Tx dehydration as necessary (enough osmotic draw to suck water from bloodstream)
Feeding frequent smaller meals
Wean sooner (discontinue milk): creep feeding, start to introduce to forage
What is vagal indigestion?Collection of dz
Mimic experimental transection of vagus nerve (actual vagus nerve involvement is unusual)
Characterized by disruption of forestomach emptying
4 types of vagal indigestionFailure of eructation
Omasal transport failure
Abomasal transport failure
Vagal indigestion of late pregnancy
Vagal indigestion Type 1 = ? what causes it?Failure of eructation
Functional causes: vagal neuritis from pneumonia or reticulitis
Mechanical causes: Esophageal obstruction, tetanus/hypocalcemia
Vagal indigestion Type 1: txTreat underlying cause. Usually reversible
Rumen trocharization
Vagal indigestion Type 2 = ? what causes it?Failure of omasal transport
Mechanical: adhesions, abscesses, FB obstruction, mass
Functional causes: Damage to enteric nervous system
Vagal indigestion Type 2: CS?Papple shape rumen
Scant greasy feces
Long hay fibers in feces
Rumen may be hypermotile
Vagal indigestion Type 2: txLaparotomy or rumenotomy to r/o mechanical obstruction
Prognosis poor if FUNCTIONAL cause (dmg to enteric nervous system)
Vagal indigestion Type 3 = ? what causes it?Failure of abomasal transport
Mechanical: adhesions, pyloric lymphosarcoma (abomasal ulcers)
Functional: Dmg to enteric nervous system
Vagal indigestion Type 3: CS?Similar to type 2. Distended abomasum contribues to L-shape
Which electrolyte can ddx Vagal indigestion type 2 & 3?WIth type 2, serum chloride will be normal. With type 3, serum chloride will be LOW
*Why is chloride low in type 3 vagal indigestion?HCl should be secreting into abomuasum. If can't move out of abomasum, gets sequestered, systemic levels are low
Vagal indigestion Type 4 = ? what causes it?Indigestion of late pregnancy
Gravid uterus may be blocking pyloric outflow, should resolve after parturition
Vagal indigestion Type 4: CS?Reduced feed intake with normal water consumption
Decreased milk production
Bradycardia: <60BPM, decreased feed intake, vago-vagal impulses
Variable rumen sounds: absent or hypermotile, usually increased (3-6/min) but ineffective contractions (weak)
Papple, rumen gas cap, ventral filling
What's going on with this peri-parturient cow?
Vagal indigestion type 4
Vagal indigestion Type 4: dx?Hx, PE (including rectal)
US (how full is rumen, of what), Radiography (r/o TRP)
Lab data: Chem, rumen analysis (chloride!)
Lab data for omasal transit failure =Usually normal, but increased rumen pH
Lab data for abomasal transit disruption =Hypochloremic metabolic alkalosis
Elevated rumen chloride (>30mEq/L)
Potentially decreased rumen pH
Abomasal outflow obstruction: which acid-base abnormality?Metabolic alkalosis
For each mEq of HCl secreted into the abomasum, there is 1 mEq of HCO3 secreted into blood. Compensatory increase in PCO2
Abomasal outflow obstruction: what can happen due to concomitant effects of hypovolemia, hypokalemia and hypochloremia?Paradoxical aciduria
Important ddx for vagal indigestionIndigestion
Bloat (gas or frothy)
Ruminal acidosis
Omasal or abomasal impaction
SI obstruction
Tx for vagal indigestionExploratory laparotomy usually required to establish underlying cause. correct problem if possible
Prognosis of vagal indigestionExtremely poor if adhesion formation or neoplasia
Can break down adhesions. Pregnant animals often improve after calving

Rumen: Disruption of microflora

Question Answer
Rumen diseases: disruption of MICROFLORASimple indigestion
Rumen acidosis (grain oveload)
Subaute Rumen Acidosis (SARA)
Traumatic reticuloperitonitis (TRP)
Simple indigestion results from?Abrupt feed change
CS of simple indigestionInappetance (usually herd issue)
Decreased production
Malodorous loose stool
MILD, not catastrophic dz
Dx of simple indigestionForestomach hypomotility
Abnormal rumen contents (dont feel good fiber mat/gas layer when ballott)
Exculde other dzs
Tx of simple indigestionSometimes time and going back to normal diet can help
Rumen transfaunation: replace microbial flora, also gives VFAs for energy burst
Rumen acidosis: caused by what?Excessive carbohydrate consumption
Which is more serious, indigestion or acidosis?Acidosis
Rumen acidosis: what happens?Rapid fermentation of excessive carbs --> excessive VFA & lactate production
Precipitous drop in pH
WHich soluble carbs can contribute to rumen acidosis?Cereal grains (especially if steamed, flaked, or ground b/c already partially broken down)
Bakery waste
Brewer's grain
In the normal rumen...Carbs ingested --> VFAs & lactate produced
What happens to the rumen with chronic exposure to a high CHO diet?It adapts! Rumen papillae elongate --> increased absorption capacity of rumen
Rumen microenvironment changes: lactate-consuming bacterial populations proliferate, protozoa die
When too much CHO is ingested, what happens with the microflora?Lactate-consuming bacteria are overwhelmed and begin to die off, while lactate-producing bacteria proliferate (acidosis worsens)
Which 2 lactate-producing bacterial species are key in acidosis?Streptococcus bovis
Lactobacillus spp.
When pH approaches 5.5, _________ proliferatesStrep bovis
When pH approaches 5.0, _________ proliferatesLactobacillus spp.
When pH <5, whats the microenvironment like?Almost all flora dead
Which form of lactate is usable by the animal?L-lactate
It's a consequence of fermentation by Strep & Lactobacillus, also a consequence of anaerobic metabolism
Utilized by host
Which form of lactate can't be used by the body?D-lactate
Produced by bacteria, builds up in bloodstream during acidosis
Chemical rumenitis, osmotic influx of fluid
3 major consequences of rumen acidosisIncreased osmotic draw
Systemic acidosis
Acid damage to rumen
Rumen acidosis: why is there increased osmotic draw?Increase in lactate --> increase in rumen osmolarity
Fluid is drawn from vascular space into rumen --> "splashy" on auscultation
Rumen acidosis: end result of increased osmotic drawSevere CV collapse and rumen distension
Hypovolemia from massive fluid shifts, decreased venous return from distended rumen
Rumen acidosis: why is there systemic acidosis too?Lactic acid is absorbed into the vasculature
D-lactate produced by bacteria, not easily metabolized by mammals so builds up in bloodstream. Also making L-lactate because of not being perfused well (anaerobic metab)
Rumen acidosis: how does acid damage occur?Rumen wall is adapted to pH 6-7
Damage occurs --> bacterial translocation from denuding of epithelium
Rumen acidosis: what's the end result of acid damage?Endotoxin moves into systemic circulation --> endotoxic/septic shock
Opportunistic infections of rumen wall (bacteria, fungus) --> mycotic rumenitis, liver abscesses, CVC syndrome, laminitis
If you saw this on necropsy what would you think
Liver abscesses from opportunistic infection of rumen wall (result of acidosis).
Fuosbacterium necrophorum crosses rumen wall, portal blood flow goes to liver
Rumen acidosis: Etiologic agent involved in liver abscesses?Fusobacterium necrophorum, gram - anaerobic bacterium (tx with penicillin)
Rumen acidosis: how does CVC syndrome happen?Septic emboli can dislodge from liver abscesses & lodge in small pulmonary vessels --> abscesses erode into adjacent vessels --> life-threatening epistaxis
The most common cause of epistaxis in cattle =CVC SYNDROME

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