Rumen & Abomasal Dz

Primary rumen contractions

-mixing of ingesta

-dense particles settles via strafiting

-cyclical contact of feed and microflora

Primary rumen contractions stimulated by

-feeding/chewing

-distention receptors

-abomasal acidity

-environmental cold to help stay warm

Primary rumen contractions inhibited by

-high VFAs

-wall too tight

-pain

-fever

Secondary rumen contractions

-move gas to cardia and clears cardiac

-requires esophagus relaxation and glottis closure for negative pressure

How are VFAs buffered?

Bicarbonate rich saliva & villi exchange VFA with electolytes

Causes of pear shape

-pregnant

-hydrops

-urinary bladder rupture

-distended SI

Causes of papple shape

Vagal indigestion

Cause of apple shape

-gas bloat

-eructation failure

Left sided ping differentials

-LDA

-pneumoperitoneum

-physometra

-pneumorectum

Right sided ping differentials

-RDA

-RVA

-cecal dilation/volvulus

-ascending colon gas

-pneumoperitoneum

-pneumorectum

-rectal palpation can help to distinguish between cecum, colon, and abomasum

When to measure rumen pH?

2-4 hours after grain and 4-8 hours after TMR

High chloride =

Abomasul reflux/outflow issues

No sedimentation

Frothy bloat or vagal indigestion

Rapid sedimentation

Poor microflora activity

New methylene blue test

All blue should be ate up by anaerobic bacteria in about 3 min

Causes of bloat

-esophageal obstruction

-partial esophageal obstruction

-frothy gas

-failure to clear cardiac

Partial esophageal obstruction

-compression from masses

-tetanus

-LDA

-usually chronic, rarely life threatening

Failure to clear cardiac

-rumen weakness from hypocalcemia

-lateral recumbency

-rumen overfill

-vagus n damage

What can cause frothy bloat?

-lush alfalfa

-alfalfa cubes

-high grain leading to s. Bovis proliferation

-high legumes

Treatment for frothy bloat

Do not tube or trochar! Go ahead and use surfactant (proloxalene) or veggie/mineral oil in non-emergencies. In emergency setting, do a rumenotomy

Prevention of frothy bloat

-more fiber

-ionophores

-lick block with surgactant

Free gas bloat - is it an emergency?

Not usually presented as an emergency but chronic

Causes of free gas bloat

-hypocalcemia weakening contractions

-lateral recumbency

-acidosis/hardware dz

-overfilled

Clinical signs of acute traumatic reticuloperitonitis

-fever

-pain/arched back/extended neck

-rumen stasis from reflex inhibition due to pain/inflammation

-anorexia

-scant, dry feces

Clinical signs of chronic traumatic reticuloperitonitis

-no fever

-wt loss

-poor production

-prolonged stasis, mat sinks = PING

-decreased rumen size

-bacterial fermentation almost abselt

Sequela of chronic traumatic reticuloperitonitis

-pleuritis/pericarditis

-reticular wall abscessation leading to vagal indigestion

Traumatic reticulopericarditis

Restrictive right sided heart failure causes jugular pulse/distention, brisket edema, washing machine murmur. If you were to do a pericardiocentesis, you would get purulent fluid with fibrin.

4 key signs of obstructive indigestion

-chronic, progressive abdominal distention

-gradual wt loss/body condition loss

-decrease in fecal volume

-papple shape

Omasal transport outflow failure causes

-abscess of reticular wall

-ostruction of omasal orifice

Pyloric outflow failure causes

-DA/RVA causing vagal n injury or significant damage to wall to lose function

-abomasal impaction

What can you expect to see on rumen fluid analysis?

Elevated chloride because the acid from the stomach passes back into the rumen

Abomasal emptying defect in suffolk sheep

Chronic weight loss, increased rumen chloride, etiology unclear and is not common anymore

Pathogenesis of rumen acidosis

Blood work of rumen acidosis patient

-hemoconcentration

-hyperphosphatemia

-hypocalcemia

-hyperlactemia

Severe vs mild rumen acidosis clincial signs

Sequela of rumen acidosis

-PEM

-laminitis

-liver abscess

-caudal vena cava syndrome

-pneumonia

-pulmonary arterial abscess

-poor weight gain (rumen wall fibrosis)

What type of vomiting is common in ruminants

Abomasal reflux = internal vomiting

Causes of vomiting

Abomasal ulcers are common in

Dairy calves/adults and beef calves

Etiologies of ulcers

-BVDV/MCF

-C perf type A in calves

-stress

-reduced perfusion

-lymphoma

-abrasive roughage

Common spot for ulcer in adult

Fundic region

Risk factors for adults for ulcers

-high energy, freshly ground diets

-fresh cows 30-40 DIM (neg energy)

-LDA

-cows in peak milk

-close-up dry cows

(Above two have to deal with perfusion)

-NSAID use

Risk factors for calves for ulcers

-mineral deficincies (copper)

-trichobezoars

-consuming sand, bedding

-feed large volume of milk in 2 feedings/day

Lymphosarcome

-common near pylorus

-can be BLV associated or not

-ulver development from disruption of mucosal integrity

Clostridial abomasitis

-c perf type A

-2-6 week old calves and lamps

-acute bilateral bloat/shock, dehydration, succusible fluid and pings

Do LDA or RSA usually present in worst condition?

RDA

Biochem abomasul reflex

Hypokalemia, hypocalcemia, azotemia, hyponatremia, hyperphosphatemia, hyperproteinemia, hyperlactatemia, hyperketonemia

Abomasal reflux sequela

-metabolic alkalosis leads to decreased bone resorption

-hypocalcemia in fresh cows

Aciduria in abomasul reflux