Production Diseases: Rumen Health & Cecum Flashcards
what is the rumen composed of
30litres/hour
40% methane
40% CO2
3 types of microbes:
- Bacteria (10^10/g)
- Protozoa (10^6/g)
- Fungi (10^4/g)
what are the characteristics of a healthy rumen (temp, pH, etc)
Warm:
- 37.5-42ºC
Moist:
- Large quantity of water
Anaerobic:
- Free of oxygen
pH:
- >6.2 to neutral
Active:
- 1-3 contractions/min
Microbes:
- Bacteria, protozoa, fungi
Large fermentation vat
what is the lactic acidosis spiral
Rapid ingestion of starch causes formation of VFAs to form which drops pH
The drop in pH causes Streptococcus bovis to take over which produces lactic acid
Lactic acid drops the pH further and causes only Lactobacillus bacteria to grow which produce more lactic acid
Eventually leads to death
what is ruminal acidosis
Metabolic disorder arising into the rumen, which affects body fluids overpassing the body buffers for a determined amount of time
To be differentiated by metabolic acidosis is a condition resulting from accumulation of acid or depletion of the alkaline reserve in body fluid
what are the 2 syndromes of ruminal acidosis
Acute ruminal acidosis
Sub-acute ruminal acidosis (SARA)
describe the fermination pattern and rumen environment
describe the pathogenesis of ruminal acidosis
Rapidly fermented:
Starches —> glucose
what effects does free glucose have on the rumen environment (3)
- Ruminal bacteria like S. bovis (lactic acid producer), which aren’t usually competitive can thrive
- Opportunistic bacteria such as E. coli can prosper and produce endotoxins or amides (histamines) when they die
- Free glucose increases osmolarity which can exacerbate accumulation of acids in the rumen by inhibiting VFA absorption
what effects does a low pH have on osmotic pressure
With low (more acidic) pH osmotic pressure is increased by greater ionization of VFAs
The ruminant absorption rate decreases
This exacerbates acidity and osmolarity
pH buffers such as bicarbonate come from saliva, the rest enters the rumen from blood in exchange for ionized acids
With concentrate diets the ruminal input of saliva decreases
A higher proportion of bicarbonate must be derived from blood
This decreases the base excess of blood leading to acidosis
what is acute ruminal acidosis
Well recognized and described
Intake of high quantities of rapidly fermentable CHO
Ruminal and metabolic acidosis
L- and D-lactate acidosis
Rapid decrease in pH
Seen in feedlots, grain beef system
Severe ruminitis
what are the clinical signs of acute rumen acidosis
Bloat
Anorexia/ruminal stasis
Severe metabolic acidosis — tachypnea, hyperpnea
Diarrhea
Dehydration, shock, recumbency
DEATH
how is acute ruminal acidosis diagnosed
History
Clinical signs
Rumen pH (<5), rumen fermentation ceased
Plasma pH or TCO2
PM
describe what happens in the rumen during acute rumen acidosis
In a relatively short time 4-8 hours ruminal pH drops until 4.5-5
At this pH, S. bovis a “ lactate producer” microbe thrive and this leads to a rapid accumulation of lactic acid in the rumen
Increased osmolality and dehydration
In addition, the chemical (acid) damage to the rumen mucosa, cause endotoxin release (LPS) and amides (histamine) and bacteria access to the portal circulation
what is the clinical picture of acute rumen acidosis
Affected cattle are completely off feed, exhibit drastically decreased milk production, dehydration and elevated HR and RR
Splashy, static rumen, cool skin surface
Subnormal temp
Diarrhea or loose manure
Weak and can be recumbent depending on the entity of electrolyte imbalance
what are the consequences of acute ruminal acidosis
Ruminitis (rumen papillae deformation, parakeratosis)
Ruminitis liver abscess complex
how is acute rumen acidosis treated
n severe emergency consider rumenotomy
Correct ruminal and metabolic acidosis and dehydration (sodium bicarb per os and IV)
Encourage feeding on forage
Rumen function stimulants ex. Pro rumen or vetrumex
Transfer or rumen contents from healthy cattle
Consider on farm emergency slaughter
what is subacute rumen acidosis (SARA)
Feeding of diets of high energy density and low fibre
Rumen pH <5.5 or 5.2
Fermentation disturbances
Economical important in high yielding dairy cattle and intensive fattening operations
Animals do not show specific clinical signs
what are the consequences of subacute rumen acidosis (SARA)
Decreased feed intake
Loss of body condition (mainly in early lactation)
Increase lameness (laminitis/white line disease)
Infertility
Diarrhea/soft feces containing undigested material
Milk fat depression (fermentation changes, decreased ratio acetate/propionate)
High culling rate
Increased mastitis
Dirty
what should be investigated during a rumen health visit (10)
- cattle outputs
- cow signs
- rationassessment and cow management
- milk records
- blood parameters
- BCS
- rumen fill score (1-5)
- fecal consistency (1-5)
- fecal sieve score (1-5)
- ruminal fluid pH
what are cattle outputs used to guide the rumen health visit
Milk records (milk yields, butterfat, protein, urea)
- Low butterfat levels can indicate ruminal acidosis
Blood chemistry (urea, BHB, NEFAs)
- NEFAs and BHB: high level indicative of fat mobilization and NEB
- Urea: high level (>6mmol/L) suggests excess dietary protein or inadequate metabolize energy
what are cow signs used to guide the rumen health
weight loss/gain (BCS)
rumen fill
feces quality
rumen fluid (pH, analysis of microbes)
cudding/rumination rate
what aspects of the ration is assessed for rumen health
DMI
ration composition
feed space per cow
ad-libitum access
how is the rumen fill score used to assess rumen health
1-5
Target scores:
- Pre-calvers: 4
- Fresh callers and peak yielders: 3-3.5
- Score below these target suggest a problem in ration (acidosis but not only)
how is fecal consistency (1-5) used to assess rumen health
1-5
Target score:
- Pre-calvers: 4
- Fresh callers and peak yielders: 3
how is the fecal sieve score (1-5) used to assess rumen health
Pre-calvers: 1-3
Fresh callers and peak yielders 1-2
how is ruminal fluid pH used to assess rumen health
<5.2 acidosis
5.2-5.8 borderline
Over 5.9 okay
Rumenocentesis
- Microscopic inspection
- Protozoal motility scoring
how is rumination rate used to assess rumen health
60% of cows lying around should be ruminating
60 chews per cud
what are the components of a good ration
DMI, ration composition
Feed space per cow, ad-libitum access
Good balanced ration
Adequate long fibre
Good quality forages
Good mixing of the diet (no sorting)
Consistency of diet
Limit parlour feeding
Cow comfort
Maximize DMI
- Adequate feed space
- Ad-lib water and feed
what are the indications of rumenotomy
Removal of foreign bodies
- Metal bodies
- Traumatic reticulitis
- Traumatic reticuloperitonitis
- Reticulopericarditis
- Obstruction
- Reticuloomasal orifice
- Located at distal part of esophagus
- Used during oral medication
Ruminal content:
- Acute toxic ingestion
- Frothy bloat
- Grain overload
- Ruminal impaction
Abscess drainage
- Perireticular
what are presurgical rumen procedures done
Antibiotic (broad spectrum)
Anti-inflammatory/painkiller (NSAID)
IV fluid therapy (if necessary)
Adequate restraint +/- sedation
Regional anesthesia block
what are the surgical techniques for rumen surgery
Left flank laparotomy
- 25cm length
Rumen serosa sutured to the skin
- Cushing pattern — cutting needle
Vertical rumen wall incision
- 3cm from dorsal and ventral margins
Remove rumen contents
- By hand + creating syphon with a tube
Explore
- Ventral sac of rumen (FB)
- Reticulum (foreign bodies and adhesions)
Palpation:
- Transruminal:
- Reticulum, omasum, abomasum
- Ruminoreticular fold
- Esophageal orifice
- cmasal orifice
Remove FB
Abscess drainage (if possible)
Magnet placement
Closure of ruminal incision (2 layers)
- 1st layer — rumen attached to skin (inverted pattern like Cushing using absorbable suture)
- Lavage
- Release rumen
- 2nd layer — oversewing skin suture holes — cushing
- Lavage + clean all debris
Release and allow to return to abdomen
Closure as for laparotomy
what are post surgery care
antibiotherapy
nsaids
what are complications of rumen surgery
Rate <5% to 15%
Peritonitis
- Painful abdomen
- Mild fever
- Drastic drop in milk production
Incisional infection
Seroma
Abscesses
how can cecum dilation and dislocation be presented as
Distention
Displacement
Retroflexion (displacement of the cecum apex in cranial direction)
Torsion (twist of cecum along the longitudinal axis)
Partial or complete obstruction to passage of ingesta
what is the clinical presentation of cecal dilation and dislocation
Acute onset of mild colic
Normal to moderately elevated HR
Decreased appetite
Reduced rumen motility
Decreased to absent feces output
Distention of the right flank
Positive succession and percussion auscultation of the right flank
where is the cecum located
apex towards to pelvic inlet
how are cecum dilation and dislocaiton diagnosed
Rectal exam + clinical exam
what will a simple cecal dilation feel on rectal exam
Rounded
Dome-shaped structure
Diameter ~15cm
Extending into the pelvic inlet
what will a simple cecal dilation + torsion feel on rectal exam
Rounded
Dome-shaped structure
Diameter ~15cm
Extending into the pelvic inlet
+
Ileocecal fold — taut, twisted painful band
Dilated loops of intestine
what will a cecal retroflexion feel like on rectal exam
Body of cecum, not the apex
Not possible to differentiate from RDA/RVA
how are cecal dilation/dislocations treated
Conservative
surgical
how are cecal dilation/dislocations treated conservatively
Early stages of simple dilation
Prokinetic drugs
Purgatives
IV infusion
when is surgical management for cecal dilation/dislocations indicated
No improvement after medical attempt in early stages
Suspected retroflexion or torsion
what are the indications of typhlotomy
drainage of cecum content
+
proximal loop of the ascendant colon (PLAC)
what are the indications for partial/complete typhlectomy
Partial:
- Cecal necrosis
- Recurrent cecal dilation-volvulus
Complete:
- Advanced cecal necrosis
- Advanced cecocolic necrosis
what is the surgical technique of typhlotomy
Local anesthesia instead of general (easier manipulation of heavy cecum with standing animal)
Right flank laparotomy
- Incision 25-30cm (vertical or slightly more caudal and caudodorsal to cranioventral direction)
Exteriorization of the apex of the cecum
Pushing gently with the palm of hand
Incision of 4cm over the apex
Contents drainage
Massage of PLAC and cecum body towards the apex
Incision closed with inverted pattern (Cushing)
Flush apex with warm saline
Replace it into abdomen
If fills again with a large volume of ingesta — repeat points 3-7
Reposition of cecum in normal anatomic position and close abdomen
what is the surgical technique for partial typhlectomy
2% lidocaine infiltrated in the ileocecal fold
Mass ligatures to prevent hemorrhage from the vessels supplying the ileum
Clamped on the mesenteric and anti mesenteric side of the cecum
Resected 2-3cm distally of the clamps
Close with two inverted layers
what are the post surgical typhlectomy/thylotomy care
Antibiotic (penicillin)
NSAID
Fluid therapy (if necessary)
Gradual introduction of diet (25%, 75%, 100% at fourth day)
Paraffin oil (3L) or sodium sulphate (300g in 10L water)
what are the complications of typhlectomy/typhlotomy
Recurrence 10% — 1st week after typhlotomy, 12.5% — 1st year
Peritonitis due to devitalization of the intestine wall or abdominal contamination during surgery
