Forestomach: Indigestion/Grain Overload/Bloat

What term is used by food animal practitioners to describe a wide spectrum of clinical syndromes in ruminants, often presumed to be an altered microbial population secondary to a rapid change in the intraruminal environment?

Indigestion

True or False: Only the rumen experiences indigestion.

False! The rumen is MOST AFFECTED, but the small intestine and cecum can be involved.

What are the TWO major forms of primary indigestion?

1. Abnormal reticulorumen CONTENTS

2. Reticulorumen MOTOR dysfunction (rumen wall, neuromuscular, impedance of ingesta)

What are the FOUR types of indigestion involved with reticulorumen CONTENTS?

1. Simple indigestions

2. Rumen impaction (poor quality feed)

3. Grain overload

4. Putrefaction of rumen

What are the FOUR types of indigestion involved with reticulorumen MOTOR dysfunction?

1. Bloats

2. Reticulitis/rumenitis

3. Traumatic reticulopericarditis (Hardware)

4. Vagal indigestions

True or False: Ruminal indigestions are more likely to occur in groups/herds rather than individuals.

True!

Secondary indigestion follows systemic illness/conditions.

Name THREE that often contribute.

1. Endotoxemia

2. Tetanus

3. Hypocalcemia

What is the most common result of subacute or chronic disorders such as microbial or fermentative indigestions, TRP, and secondary indigestions?

Prolonged ruminal stasis (anorexia)

Describe how a cow would present with prolonged ruminal stasis. (4)

Reduced rumen fill, "tucked-up", firm/doughy contents ventrally, gaunt appearance

What is the general term for a poorly defined entity of inappetence, decreased reticulorumen motility, and abnormal feces, with a nonspecific causes that involves intake of anormal feed?

Simple indigestion

Describe how a simple indigestion would present in terms of apple, papple, or pear shape.

Apple on the left

True or False: To obtain a diagnosis of simple indigestion rather than more specific indigestions, you typically just need to rule out your other differentials.

True!

Name the FIVE major ways to treat simple indigestions.

1. Tincture of time (self-resolves)

2. Transfaunation

3. Good quality hay

4. Laxatives

5. Gradual reintroduction of concentrates

What is the goal of all treatments of simple indigestion?

Facilitate return to normal function and motility

What amount of transfaunation is normal in an adult cow?

8-16 L

(Notes say 3L minimum and 15-20L are administered so who the hell knows)

What kind of hay would you want to provide to a cow with simple indigestion (what makes it good quality)?

Long-stemmed fiber

What are the TWO major laxatives used for simple indigestion?

1. Magnesium oxide (MTV; MagLax)

2. Mineral oil

Why is overzealous use of laxative discouraged in simple indigestions?

Strong alkalinizing agents which can impact rumen pH and disrupt protozoa

(You'd want to use this in cases of ruminal acidosis to bring that pH up but would use something like vinegar in cases of an alkalinized rumen to bring the pH down. It's just a way to ebb and flow and neutralize that pH closer to normal depending on the situation.)

True or False: Parenteral A vitamins may be helpful in simple indigestion until normal rumen function is reestablished.

False! Parenteral B vitamins may be helpful in simple indigestion until normal rumen function is reestablished.

You administer MagLax to a cow with a ruminal and small intestinal simple indigestion. What major side effect should you warn your client of and when should it go away?

Diarrhea that should go away in 12-24 hours

When collecting rumen fluid, it is good for ———- at room temperature and ———- when refrigerated.

What is often placed on top of stored rumen fluid and why?

1/2 day

24 hours

Thin layer of mineral oil to keep anaerobic

You are called out to examine a nearby steer. Upon arrival, the cow is not in distress but you notice he looks fat as hell. After a physical and some diagnostics, you can safely say the rumen is distended with firm, doughy contents that accumulate ventrally and a free gas bloat is present. The cow has no other abnormalities.

What is your major differential?

Ruminal inactivity with indigestible roughage (hay belly)

Name FOUR of the six potential ways you could treat hay belly.

1. Improve forage quality

2. Restrict to readily digestible feed in small meals

3. Transfaunation

4. B vitamin supplementation

5. Laxation and dissolution of contents (mineral oil; DSS)

6. Empty rumen/abomasum if extremely impacted

You are called out to observe a bottle-raised calf that has been doing poorly for quite some time. He has a long hair coat, poor BCS, pasty feces, mild bloat, and a potbelly abdomen. On succussion, there are tinkling fluid sounds. Upon talking more with the producer, you realize that he is new to owning cattle.

What is your primary differential?

Rumen drinker

What are the THREE most important causes of rumen drinkers?

1. Inappropriate diet

2. Poor transition during weaning

3. Failure of esophageal groove

Putrefactive indigestion is due to —————————— and can result in ———————-.

Abnormal feeds or milk in rumen

Acute or chronic D-lactic acidosis

What would rumen fluid smell, look, and have a pH of with rumen drinkers with a calf?

What would look and pH be if this were an adult?

Smell: foul

Look: grey-white; concrete-like; sometimes curds

PH: <6

Look: dark black liquid to solid contents

PH: 7.5-8.5

You have confirmed a case of rumen drinker. What FIVE treatment components are you going to do?

1. Remove abnormal rumen contents (siphon/rumenotomy)

2. Transfaunation (repeated healthy establishment of microbiome)

3. Correct dehydration (give alkalinizing fluids if calf metabolic acidiosis)

4. B vitamins

5. Feed management (green grass; calf starter and wean when appropriate)

Is evaluating rumen chloride helpful in cases of rumen drinkers, especially calves?

Why or why not?

No- rumen chloride is typically higher in milk-fed animals.

What is the most dramatic cause of D-lactic acidosis?

Grain overload

The pathophysiology of grain overload involves the abrupt ingested of rapidly fermentable CHOs, which alters the ——————- of the rumen environment.

This causes a predominance of —- and —- organisms, which produce ————— and increased ——————.

This development cause pH to (increase/decrease), which can damage the mucosa and result in rumenitis

Normal flora

Streptococcus (S. Bovis) and Lactobacillus

Lactic acid (D and L-isomers)

VFAs

Decrease

True or False: It's not just grain that can cause grain overload. Any fermentable carbs, grains, or high-carb byproducts like bakery waste, fruits, or vegetation can also cause rumen acidosis in the same manner.

True!

What are cases of ruminal acidosis prone to that can dramatically impact systemic circulation?

Translocation of bacteria into the bloodstream

True or False: Die-off of the rumen flora also releases also releases significant concentrations of inflammatory mediators, including histamine and endotoxins. LPS from G- bacteria can exacerbate this.

True!

Say an animal has severe ruminal acidosis caused by grain overload and its pH drops to 5. What is this animal most likely to succumb to?

What are some of the major sequelae of rumen acidosis? (6)

Hypovolemic shock (rumen fluid increases in osmolality; severe dehydration)

Laminitis, liver abscess, chronic rumenitis, mycotic rumenitis, polio, bacteremia

Here's that picture she said we need to know on slide 17:

The cow is going to eat lots of ———-. In the rumen, those are turned into —-, which becomes —- through glycolysis. Once this is done, bacteria can then make —- and ————-.

When this happens too much, —- builds up inside the rumen and pH (increases/decreases). Osmolality also (increases/decreases), which causes water ———————————-. This buildup is absorbed into the bloodstream and impacts the pH in the same way.

This leads to —— ——-.

Fermentable starch/CHOs

Glucose

Pyruvate

VFAs

Lactic acid (D and L-isomers)

Acid

Decreases

Increases

To pull within rumen -> sloshy/distended rumen

Rumen acidosis

When do clinical signs of grain overload begin?

12-36 hours post-ingestion

You are presented with a cow with anorexia and rumen motility. It has cold limbs and it is tachypneic and tachycardic. It stumbles around the pasture and has abdominal distention. Succussion reveals musical tones of a very fluid rumen.

What question would you want to next ask the producer based on presentation?

Has it gotten into anything? (Grain Overload)

What are the FIVE major diagnostics suggestive of grain overload/rumen acidosis?

1. History/risk factors

2. Rumen pH <5

3. Shift to G+ flora

4. Blood gas pH <7.2

5. Urine pH acidic

With the destruction of rumen flora and lack of thiamine production, what major neurological disease are animals with rumen acidosis susceptible to?

Polioencephalomalacia

What is the major treatment that must be done in ruminal acidosis?

Empty the rumen (lavage via Kingman tube or rumenotomy & rinse)

True or False: Ruminotomy is often recommended for ruminal acidosis if pH <5, heart rate >100/min, dehydration greater than 8%, and rumen distention indicating severe grain overload.

True!

What are FIVE other treatments that should be done for ruminal acidosis?

1. Rumen buffers

2. IV fluids (sodium bicarb to neutralize acidosis)

3. Transfaunation

4. NSAIDs and antibiotics

5. B vitamins (thiamine at 10 mg/kg)

What are THREE major rumen buffers used for ruminal acidosis?

1. Magnesium hydroxide (1g/kg)

2. Enough warm water to disperse (2-3 gallons)

3. Activated charcoal (2 g/kg)

What are THREE major ways to prevent ruminal acidosis?

1. Ration evaluation

2. Bunk management

3. Use of ionophores antibiotics (stabilize microbiota)

What TWO bacteria are most associated with rumenitis?

1. Fusobacterium necrophorum

2. Trueperella pyogenes

What can occasionally occur in the rumen with chronic antibiotic use that can wipe out the microbiome and is often fatal?

Mycotic rumenitis

You are called out to see a commercial dairy cow. After getting a history from the owner, you learn the cow has had decreased milk production, decreased milk fat percentage, decreased feed consumption, and decreased cud chewing time. You ask what the cow is getting fed, and you learn the diet involves high amounts of high carb, low fiber content.

What is your primary differential?

What THREE sequelae should pop up in your mind that you'll want to check this cow for?

Subacute ruminal acidosis (chronic rumenitis)

1. Liver abscesses

2. Caval syndrome

3. Laminitis

True or False: A cow with SARA is more likely to experience abomasal disease (displacements), indigestions, diarrhea/enteritis, and ketosis.

True!

What should you do when SARA is suspected?

Determine rumen pH on several cows via rumenocentesis 2-4 hours after eating, where 5.3-5.7 supports diagnosis. A pH of 5.5 in 5 or more cows within n=12 can serve as a cutoff to define SARA.

What should you encourage a producer to do when SARA is confirmed in his herd?

Consult with nutritionist to examine ration/mixing to see what the cows are actually eating

What condition that can be acute or chronic involves excessive accumulation of gases within the rumen that results in abdominal distention?

Ruminal tympany (bloat)

True or False: Ruminal bloat typically result in a left-sided apple in the dorsal and ventral quadrants, but can be bilaterally apple in severe cases.

True!

True or False: Free gas bloat is a disorder in itself.

False! Free gas bloat is NOT a disease in itself, but rather the result of an underlying primary disorder.

When can the contents of the rumen inhibit eructation in terms of bloat?

What does this result from?

Stable foam (frothy/slime bloat) is formed from mucopolysaccharide

Rapid breakdown of offending diets (alfalfa, clover, etc.) and bacterial proliferation, releasing stabilizing agents that are highly viscous and traps air bubbles.

True or False: Frothy bloat involves the breakdown of chloroplasts, soluble proteins, and very fine particles. This, coupled with the mucopolysaccharide, makes gas stable in foam.

True!

True or False: Bouts of acidosis predispose to bloat.

True!

Bloat is associated with (low/high) concentrate diets.

High

Name FOUR forages with high bloat potential and TWO with medium.

High: alfalfa, red clover, sweet clover, winter wheat

Medium: oats, perennial ryegrass

You are called out to examine a cow. Upon first look, you notice she has a left-sided apple and acts colicky. Her limbs are slightly cold and her breathing is irregular.

What is the next thing you should do that is both diagnostic AND therapeutic?

What would you expect to find there based off of the history?

What is this condition?

Why might you need to act quickly?

Pass a stomach tube

Stable foam at cardia with a lack of free gas

Frothy bloat

Death can occur in 30 minutes to 4 hours

What are the THREE major post-mortem findings of frothy bloat?

1. Stable foamy rumen contents

2. Congestion of head/neck with pallor of caudal part of carcass

3. Bloat line

You are called out to treat a bloat. After you initially place a stomach tube, how can you differentiate from free gas and frothy bloat?

Free gas will quickly decompress, while stable foam in frothy bloat seldom freely flows from the tube

True or False: You can use fluid from a kinked stomach tube to help diagnosis type of bloat.

True!

If you do NOT have multiple cows affected due to bloat-provoking diet in frothy bloat, what is most likely the culprit?

Omasal transport failure

True or False: Frothy bloat is only seen is multiple animals are affected.

False! Frothy bloat is NORMALLY seen affecting multiple animals, but can impact a single animal based on management and herd specifics plus the response to empirical therapy.

You pass a tube into the rumen, but there is resistance. What are the primary differentials if your tube is able to push into the rumen or is NOT?

Yes: Esophageal disorder

No: Choke

What should you use to relieve bloat in an emergency?

Oral speculum and tube or trocar

Aside from stomach tube, what FOUR major things should be done to treat a frothy bloat?

1. Antifoaming agents

2. Remove offending diet/NPO

3. Emergency rumenotomy

4. Management (ration, bunk management, pasture management)

What THREE major antifoaming agents are used in frothy bloat?

Which is considered the best?

Which would be best for slime (grain) bloat?

1. Poloxalene (2 oz/1000 lbs)

2. Mineral/vegetable oil (1 to 2 pints/1000 lbs)

3. Dioctyl sodium sulfosuccinate (2 oz/1000 lbs)

Poloxalene

Mineral or vegetable oil

What TWO major management things are done for frothy bloat?

1. Poloxalene top dressing, molasses blocks, liquid supplementation

2. Ionophores (reduce incidence)

Next are some super cool review questions from swaggy J-Bayne.

Awesome!

Characterize the shift in the population of microorganisms that occurs during severe grain overload.

G- to G+

What metabolic products drive the increase in the osmotic gradient and decrease in pH within the rumen during grain overload?

VFAs

What are the TWO purposes of oral administration of magnesium oxide to a bovid with indigestion?

1. Laxative- exit of ingestion

2. Buffer pH

List THREE potential sequela of ruminal D-lactic acidosis.

1. Polioencephalomalacia (give thiamine)

2. Laminitis

3. Liver abscesses (could condemn carcass)

Hold on hold on hold on

Fortnite move!!!!!