Indigestion in Ruminants 2 Flashcards
carbohydrate engorgement of ruminants happens due to:
¤ Access to highly fermentable feedstuffs
¤ by unaccustomed animals, or
¤ in larger than normal amounts
carbohydrate engorgement of ruminants - speed of clinical course
rapid
etiology of carbohydrate engorgement? what types of food?
¤ Sudden ingestion of toxic amounts of carbohydrate-rich feed
> Grains
<> Most toxic: wheat, barley, corn
<> Less toxic: oats and sorghum
> Finely ground feeds with large surface area promote rapid fermentation
> Apples, grapes, bread, baker’s dough, sugar beet, mangels, sour wet brewers’ grain
pethogenesis of carbohydrate engorgement
grain overload > strep bovis overload > lactic acidosis > severe drop in pH
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¤ Increased of VFAs
¤ Decreased rumen pH
¤ Decrease rumen motility
¤ Increased Lactic acid (D and L isomers)
¤ Acid resistant Lactobacillus spp. proliferate producing lactic acid
¤ Increase rumen osmolality (280mOsm/L to ≈400 mOsm/L)
what species / animals are susceptible to carbohydrate engorgement? trigger?
¤ Cattle and sheep are susceptible
¤ Common in feedlot and dairy cattle
¤ Rapid change in high energy ration
¤ Accidental consumption of large quantities of grain
morbidity and mortality for carbohydrate engorgement
¤ Morbidity: 10-50%
¤ Mortalities:
> Non-treated animals: up to 90%
> Treated: 30-40%
carbohydrate engorgement GI clinical findings
¤ Abdominal pain
¤ Dehydration (6-12 %)
¤ Diarrhea – fluid, fetid
¤ Splashy rumen, bloat
¤ Rumen fluid analysis
> pH < 5
> sour odor
> protozoa dead, predominance of gram +
rumen fluid analysis for carbohydrate engorgement
¤ pH < 5
¤ sour odor
¤ protozoa dead, predominance of gram +
vital signs Clinical findings for carbohydrate engorgement (demeanor, appearance, HR, RR)
¤ Depression
¤ Lameness
¤ Scleral injection
¤ Elevated temp initially, may progress to subnormal (shock)
¤ HR = 80-140 bpm
¤ Respiratory rate elevated (blow off CO2)
carbohydrate engorgement clinical findings
- acidosis?
- blood?
- enzymes?
- electrolytes?
- Metabolic acidosis
- Increased PCV and total protein
- Elevated BUN and creatinine (azotemia), phosphorous
- Increased anion gap
- Decreased calcium (hypocalcemia)
how does lactic acid in the rumen cause issues?
¤Lactic acid accumulation in the rumen increase the rumen fluid osmolarity, drawing more body water into the rumen (creates the “splashy rumen”)
¤Loss of body water causes dehydration contributing to acidosis
¤Lactic acid is absorbed from rumen as well as from small intestine & profound lactic acidosis develops
Chemical and mycotic rumenitis, liver abscessation
- how does this develop from carbohydrate engorgement?
¤ Acidic rumen pH damages mucosal surfaces in the forestomachs & intestine
¤ Blood vessels thrombosis & sections of rumen mucosa & submucosa slough allowing bacteria to invade
¤ Bacteria travel to liver via portal circulation & cause liver abscesses
¤ Mycotic rumenitis may develop
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¤ Lactic acidosis > rumenitis > bacterial access to systemic circulation
bile duct and renal sequelae of carbohydrate engorgement
¤ Lactic acidosis > rumenitis > bacterial access to systemic circulation
¤ Diffuse coagulation and hyperplasia of bile duct epithelium
¤ Renal tubular degeneration may occur
what bacteria are implicated in hepatic abscessation due to carb overload?
¤ Fusobacterium necrophorum & Archanobacter pyogenes
what other toxins increase in a case of carb overload? what do they cause?
¤ Histamine levels increase
¤ Ethanol, methanol, tyramine, tryptamine production
contribute to CNS depression
¤ Thiaminase production may result in development of polio
¤ Death of Gram – bacteria can cause endotoxin release
diagnosis for carbohydrate engorgement
¤ History
¤ Clinical signs and clinical findings
¤ Rumen fluid analysis
> <5
> Absence of protozoa
> G- replaced by G+ bacteria
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¤ Biochemistry panel
> Hemoconcentration
> Hyperlactetamia
> Hypocalcemia
> Low bicarbonate
¤ Blood gas analysis
> Lactic acidosis
¤ Urine
> pH <5
Treatment for carbohydrate engorgement
¤ Correct ruminal and systemic lactic acidosis > Sodium bicarbonate IV
¤ Prevent further lactic acid production
> Alkalinazing agents intraruminally
<> Magnesium hydroxide
¤ Restore fluids and electrolytes
> Hypertonic NaCL, Lactated Ringer’s solution
¤ Restore forestomach and intestinal motility
¤ Rumenotomy
¤ Rumen lavage
> Kingsman tube
¤ Antibiotics
¤ Antihistamines
Sub-acute Ruminal Acidosis (SARA) definition
¤ Definition: acidosis is a decrease in the alkali (base excess) in body fluids relative to the acid (hydrogen ion) content.
¤ Ruminal acidosis > ingestion of large amounts of highly fermentable, carbohydrate-rich feeds > excessive production and accumulation of lactic acid in the rumen.
SARA: Causes
¤ inadequate ruminal buffering
¤ inadequate adaptation to high carbohydrate diets.
¤ Diets with excessive (over about 15%) long forage particles can paradoxically increase the risk .
¤ In general major causes for subacute ruminal acidosis are lack of coarse fiber and/or excess concentrates in the diet, feed sorting, rapid diets changes, and engorging.
is rumen pH constant throughout the day?
- no, it goes through major and minor cycles
- range ~5.4 (around noon) - 6.6 (midnight)
what is rumen bloat? what are the forms?
¤ Gas production is a normal occurrence during rumen fermentation
¤ Excessive retention of gases of fermentation
¤ Bloat occurs if eructation is prevented for any reason
¤ Abnormal distention of rumen and reticulum
¤ Forms:
> Foamy (primary)
> Free gas (secondary)
how often does normal eructation occur in ruminants? how much gas per minute?
- Eructation, or belching, normally occurs about once every minute and requires about 10 seconds to be completed.
- 2L of gas per minute
layers of material in the rumen, from top to bottom
Top
- gas pocket
- layer of coarse hay and low density particles
- liquid ingesta layer; medium density
- fine particles; high density
Bottom
primary rumen tympany (frothy bloat)
- pasture vs feedlot bloat causes
¤ Leguminous (pasture)
¤ Finely ground grain (feedlot)
¤ Secondary rumen tympany (free-gas bloat)
- what causes this?
¤ Diets that lead to excessive gas production
¤ Failure to eructate
epidemiology of pasture bloat
¤ Lush pastures
¤ Spring and autumn
epidemiology of feedlot bloat
¤ Large quantities of grain/little roughage
Bloating forages
¤ Alfalfa (Medicago sativa)
¤ Red clover (Trifolium pratense)
¤ White clover (Trifolium repens)
¤ Sweet clover and alsike clover
¤ Cereal crops, rape, cabbages, peas, bean, young grass
Feedlot bloat risk factors
¤ High-level grain finishing ration
¤ Roughage component is alfalfa
pathogenesis of bloat?
- normally, gas bubbles in the rumen float up to form gas cap
- eructation removes gas
> for dairy cow on grass: 100L/h; on legumes: 200L/h
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In bloat:
1. gas bubbles dispersed throughout the rumen
2. inadequate coalescence of gas bubbles
3. inhibition of eructation
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¤ Production of stable, proteinaceous FOAM
¤ Formed from leaf cytoplasmic 18-S soluble protein and saponins
¤ FOAM traps normal amount of gases
> CO2, methane
¤ FOAM prevents the coalescence of small gas bubbles
¤ Gas remains trapped in the rumen fluid
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¤ Cardia cannot be cleared of FOAM > Eructation cannot occur > Gaseous distension of rumen > Pressure on large veins (posterior vena cava) > decreased venous return > increased blood pressure
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¤ Gaseous distension of rumen > Decreased thoracic volume > Hypoxia > Death
clinical findings with bloat
¤ Distended left paralumbar fossa
¤ Discomfort (grunting, colic)
¤ Open-mouth breathing
¤ Anorexia
¤ Salivation
¤ Anxious
¤ Depressed terminally ¤ Sudden death
therapy for free gas bloat
¤ Pass a stomach tube (carefully) either nasogastric or
orogastric
¤ If positional, roll cow into sternal recumbency
¤ Force exercise
¤ If hypocalcemia, administer calcium
¤ Rumen stimulants
¤ Rumen trocharization or rumenotomy for emergencies only
Rumen Tympany-”Bloat” - is this serious?
¤ EMERGENCY!!
Rumen Tympany-”Bloat” - what may happen with mild cases? what should we feed? what type of bloat is stomach tube good for?
¤ Mild cases may spontaneously regress
¤ Feed coarse, stemmy hay
¤ Pass stomach tube: NOT effective in “frothy” bloat
what are our aims for frothy bloat treatment?
¤ 1. Lower the surface tension and viscosity of foam
¤ 2. Promote coalescence of bubbles of gas
in a frothy bloat case, do we prefer drenching or intra-ruminal injection or stomach tube administration? what is the goal of this?
Drenching preferable to intra-ruminal injection or stomach tube administration
¤ Clears cardia of froth
Rumen Tympany-”Bloat”
- anti-foaming agents
¤ Synthetic non-ionic detergents:
¤ “AlfasureTM” -; Polaxalene (1,2-Propyleneglycol, ethoxylated and propoxylated). Rafter Products, Calgary, AB
¤ Alcohol ethoxylate detergent (“Blocare”)
¤ Oils:
¤ Peanut oil; Vegetable oil (120-180 ml)
¤ Mineral oil (120 ml);
¤ Dioctyl sodium sulfosuccinate (“Tympanex”)
how do we administer anti-foaming agents for frothy bloat?
¤ Directly injected to rumen ( 14g needle)
therapy for frothy bloat, to reduce surface tension? mechanism?
- Poloxalene – 2 oz.
- Household detergent (Tide 2-3 oz.)
- Mineral oil
- Dioctyl sodium sulfosuccinate (DSS)
*All of the above reduce surface tension allowing consolidation of tiny bubbles into a free gas bloat which can be eructated or relieved via tube
Rumen Tympany-”Bloat”
- prevention - pasture management
¤ Avoid grazing legumes between 0700-0800 hrs - high risk period
¤ Graze on mixed grass/legumes
¤ Mature grass-dominant pastures
¤ Feed roughages before turning onto legume- dominant pastures
Rumen Tympany-”Bloat” - preventative anti-foaming agents
¤ “AlfasureTM” (Poloxalene) in water supply
¤ Drench 2x daily with detergents
¤ Feed anti-bloat supplements (poloxalene)
¤ Strip grazing and pasture spraying
¤ tallow or mineral oil emulsions
¤ Legumes that are “bloat-safe”
what is the etiology of chronic bloat? therapy?
- Chronic bloat – typically free gas bloat associated with high grain diets that may cause a permanent shift in microbiota
– Increase fiber in diet & reduce grain
– Rumen transfaunation
– Temporary rumenostomy in severe cases - May be 2° to another problem such as vagus indigestion
how to remove rumen contents
¤ Kingman tube
¤ Rumenotomy
¤ Ice water administration
what other therapies can be combined with rumenotomy?
*Fluid and electrolyte replacement IV
*Anti-inflammatory agents –flunixin meglumine (Banamine)
*Antibiotics
*Antimycotic therapy
*Rumen transfaunation
*Thiamine
*B-complex vitamins
Client education for bloat - important considerations for prevention
- Slow adaptation to grain
- Limit legume grazing
- Poloxalene in feed, molasses, salt or block
- Maintain sufficient long stem hay (fiber) in ration to stimulate good rumen motility
¤ Make dietary changes very gradually
> Addition of antibiotics, HCO3-, and ionophore antibiotics to the feed have been beneficial but do not replace good management
¤ Rumen adaptation may take 6 weeks
