Disease of the Abomasum 1 + 2 Flashcards
Describe the aetiology and epidemiology of abomasal disease in cattle
Dairy animals
Associated with high yield and concentrate feeding
Primary event is abomasal atony
- Excessive VFA in abomasum
- Inflammatory cytokines
How do inflammatory cytokines affect the abomasum?
Inhibit motility
List some risk factors for abomasal disease
- Usually seen in early lactation
- Housing
- “Imbalance of fibre and concentrate” - SARA
- Associated with ketosis and FMS
- Hypocalcaemia (clinical & sub-clinical)
- Concurrent inflammatory disease
- Cow comfort, lameness
- Reduced DMI
On farm what would you asses/investigate to gather information to support an abomasal disease diagnosis
- Nutrition: Lactating diet, Dry cow feeding
- Housing and comfort: lying time
- Concurrent disease e.g. endometritis, mastitis
What is the most common abomasal disorder?
Left displaced abomasum ‘twisted stomach’
How is the blood supply affected in an LDA?
Not compromised, unlike on the RHS
What are the clinical signs of a LDA?
- Reduced milk yield (not as marked or sudden as a “wire” – insidious)
- Not reaching expected yield – parlour monitoring
- Ketosis
- Selective appetite: prefers fibre
- Usually 0 – 4 weeks post calving
What are the DDx for a LDA?
- Vagal indigestion
- Peritonitis
- Gas in the rumen
What is ‘pinging’?
Ping the left side of the cow by simultaneously percussing and ausculting the whole left side of the cow by firmly flicking your finger against the body wall of the cow.
A “ping” represents a fluid-gas interface.
On the left side of the cow, gas may be present in the abomasum (LDA), rumen, or peritoneal cavity.
Describe the abomasal sounds heard in a LDA
- Spontaneous – tinkling & gurgling
- Ping – tap or flick rib hard – resonant ping
- Map out area of “pings”
Absence of rumen sounds over displaced abomasum
Anatomically the abomasum is fixed by which 3 structures?
Omasum
Duodenum
Omentum
How does the abomasum become displaced on the LHS?
Despite being fixed by 3 structures the middle portion of the abomasum is able to travel.
As the rumino-reticulum contracts, the abomasum buoyed by gas works its way to left side
How can you use rolling to treat a LDA
- Cast
- Right lateral recumbency
- Then roll to dorsal to move abomasum onto right side
- Then roll over to left lateral
- Ping to see if moved – can repeat - Good quality roughage.
What are the advantages of rolling to treat a LDA?
Cheap and quick
Non-invasive.
Concurrent disease - Not putting the animal through surgery so good if it has other problems occurring
What are the disadvantages of rolling to treat a LDA?
Least successful of all treatment
Can cause ulcer rupture
How can you use toggling to treat a LDA
A toggle is passed through the skin into the abomasum whilst the cow is lying on her bac
- No sedation
- Place sutures where abomasum naturally lies
- Cast
- Maintain in dorsal
- Auscultate
- Push trochar firmly into abomasum
- Caudal toggle placed. Clamp on
- Cranial suture placed (10 cm cranial to first suture) - Let gas escape.
- Loose tie – 10-12 cm
- Roll over
What are the advantages of toggling to treat a LDA?
Cheap and quick
Minimally invasive
Relatively straight forward
What are the disadvantages of toggling to treat a LDA?
Going in blind
Do not see if Abomasum has ulcers/adhesions
Fistula formation
Risk of getting kicked
Which organs lie on the LHS of a cow?
Rumen
Reticulum
Which organs lie on the RHS of a cow?
Liver
Omasum
Gall bladder
Jejunum
Small portion of abomasum seen - mostly lies ventrally
What are the 4 surgical approaches for an LDA?
L & R sided approach – 2 operators
L side (Utrecht)
R side
R paramedian approach – cow is cast
Describe the left to right/bilateral flank surgical approach for a LDA
- Para-vertebral nerve block
- Incision – 5cm caudal to last rib.
- Both slide hand down wall of abdomen and shake hands.
- Decompress abomasum: manual / needle on flutter valve tube
- Push abomasum to midline
- Pull up to R. incision
- Omentopexy - suture to omentum
Describe the right side surgical approach for a LDA
- Identify the pylorus – “sows ear”
- Pylorus palpated – “sausage”
- Omentopexy using omentum near pylorus
- Stitch the omentum by pylorus into wound closure.
- Put hand over rumen in backwards direction and feel top of abomasum on L side (14g needle on tubing to release most of gas)
- Put arm (R?) in abdomen- follow R body wall down and under to L side
- Identify abomasum (slight gas still in it)
- Grasp abomasum/omentum securely
- Firmly sweep down and pull to incision
- Identify “sows ear” & pylorus
- Omentopexy as described earlier
Describe the left side surgical approach for a LDA
- L side incision
- Grasp greater curvature of abomasum or omentum
- Weave suture through omentum or abomasum – leave 2 long ends (3 ft)
- Decompress abomasum with 14G needle and tube
- Attach needle to first thread (cranial)
- Take down along body wall to R. ventral midline site (assistant guides from outside with forceps)
- Penetrate body wall with needle – unthread needle
- Repeat with caudal suture (4” caudal)
- Reposition abomasum down onto ventral abdominal as assistant “takes in” sutures
- Tie sutures tight – make sure no guts trapped between abomasum and body wall
Describe the ventral abdominal paramedian surgical approach for a LDA
- Sedation / full GA
- Dorsal
- Line block
- Incise where abomasum normally lies
- Locate abomasum- should have returned.
- Using cat gut, 4-6 mattress sutures through abomasum wall, peritoneum and abdominal wall.
- Suture up.
Describe the post-operative care needed for cows that have undergone surgery to treat a LDA
Antibiosis ? - Pen/Strep, Oxytetracycline
Treat underlying conditions
Ketosis – propylene glycol
Endometritis etc (or treat pre-surgery?)
High fibre diet
Describe the aetiology of a right displaced abomasum
Not fully understood.
Similar to LDA but less common.
Progression
- Dilation & distension
- Displacement
- Torsion
Describe the aetiology of a right displaced abomasum
Not fully understood.
Similar to LDA but less common.
Progression
- Dilation & distension
- Displacement
- Torsion
Describe the aetiology of a right displaced abomasum
Not fully understood.
Similar to LDA but less common.
Progression
- Dilation & distension
- Displacement
- Torsion
Describe the metabolic sequence that follows dilation of the abomasum on the RHS
- Pooling of H+ and Cl- in abomasum
- (upper intestinal obstruction): Metabolic alkalosis, Hypochloraemia
- 35 – 50 litres in abomasum
- Dehydration
Describe the metabolic sequence that follows dilation of the abomasum on the RHS
- Pooling of H+ and Cl- in abomasum
- (upper intestinal obstruction): Metabolic alkalosis, Hypochloraemia
- 35 – 50 litres in abomasum
- Dehydration
Increased luminal pressure in the abomasum due to dilatation leads to?
Mucosal damage
Describe the volvulus phase of a RDA
Dilatation and clockwise torsion of the abomasum
Dilation and anti-clockwise torsion of the abomasum
- blocked omasal/abomasal opening
- venous return to the abomasum is impaired
- ischaemic necrosis due to blocked arterial flow
Describe the metabolic sequelae of displacement and torsion in a RDA
- Mucosal damage
- Cytokine release & endotoxaemia
- Metabolic acidosis
- Severe dehydration
What are the clinical signs of the dilation and displacement phase of a RDA
- Inappetent / depressed.
- Reduced faeces.
- Dehydrated.
- Tachycardia.
- Pale MM and dry.
- Doughy rumen – total outflow obstruction
- Reduced rumen turnover.
- Ping (middle to upper 1/3rd right side of abdomen)
- Tense viscus felt cranially per rectum.
What are the clinical signs of the torsion phase of a RDA
Much sicker
Severe dehydration
What are the DDx of a RDA?
Abomasal impaction
Caecal torsion
Traumatic reticulitis
Intestinal obstruction
Describe how you could treat the dilation/displacement phase of a RDA medically
- Ca 40%
- Metoclopramide – not authorised in cattle – no MRL
- Buscopan – not authorised in milking cattle – 2 day meat withhold for calves
- Fluids
Describe how you could treat the dilation/displacement phase of a RDA surgically
Drain and replace
Describe how you could treat the torsion phase of a RDA
Slaughter
Surgery?
Describe the surgical procedure used for a RDA
- Give fluids pre-operative: Hypertonic saline -5 litres
- Purse string suture
- Tube and Drain
- Leave some fluid as indicator
- Rotate abomasum
- Watch duodenum
- Anchor pylorus
- Stitch up
Describe the post-operative care needed for a cow that has undergone surgery for a RDA
Fluid therapy 50 – 100 litres (Hartmanns like)
NSAID
Antibiosis
Oral KCl (50g daily)
Ca 40%
Propylene glycol
Describe the post-operative care needed for a cow that has undergone surgery for a RDA
Fluid therapy 50 – 100 litres (Hartmanns like)
NSAID
Antibiosis
Oral KCl (50g daily)
Ca 40%
Propylene glycol
How can you help prevent a RDA?
Better dry cow management
What are the clinical signs of intestinal conditions in cattle?
- Sudden milk drop
- Anorexia
- Ruminal stasis
- Abdominal pain: kicking flank, getting up and down
- Minimal passage of faeces
- Mild right sided bloat
List the DDx for intestinal conditions in cattle
- Intestinal obstruction
- Foreign body
- Intestinal volvulus/torsion
- Intussusception
- Intestinal strangulation
- Neoplasia
- Jejunal haemorrhage syndrome
- Peritonitis
- Acidosis
How can intestinal conditions be investigated and diagnosed?
- Clinical signs
- Rectal palpation
- Ultrasound
- Post mortem
What signs/conditions would indicate intestinal surgery is needed?
- Rapid deterioration
- Severity of colic and its response to analgesia
- Severity of the abdominal distention
- Absence of faecal output
- Heart rate
- Rectal palpation findings
- Blood lactate
- Blood Calcium – if low treat medically initially
What is jejunal haemorrhagic syndrome?
Possible clostridium perfringens type D toxicity
Causes anorexia and lethargy
How would a cow with caecal dilatation and volvulus present?
- Dairy cow in first few months of lactation
- Inappetant
- Decreased milk yield
- Ping in dorso-caudal right sublumbar fossa.
- Rectally: Distended, recognisable viscus into the pelvis.
Describe the aetiology of caecal dilatation and volvulus
- Excess carbohydrates are fermented in the caecum
- Increased VFAs and decreased pH
- Caecal atony
- Accumulation of ingesta and gas
Describe the pathogenesis of caecal dilatation and volvulus
Similar to abomasal displacement.
- Atony
- Dilatation
- Torsion
- Volvulus: blind end is rotated cranially, body is distended.
Torsion
- Can occur with volvulus.
- Twists longitudinally
How would a cow with caecal dilatation present?
- Anorexia
- Mild abdominal discomfort
- Reduced milk yield
- Reduced faeces
- Ping in the right sub-lumbar fossa
How would a cow with caecal dilatation and volvulus present?
Dehydration
Tachycardia
Abdominal pain
How would a cow with caecal dilatation present on a rectal exam?
Long cylindrical, movable organ
Blind end points to pelvic cavity
How would a cow with caecal dilatation and volvulus present on a rectal exam?
Points cranially and laterally OR medially
How can caecal dilatation and volvulus be treated medically?
Depends on severity
Good quality hay
TLC
Monitoring hydration and heart rate
How can caecal dilatation and volvulus be treated surgically
- Purse string suture
- Small incision
- Milk caecal contents out
- Once deflated, correct torsion and suture up
Describe the aetiology of abomasal ulcers
Primary: ?
Secondary: To other diseases i.e. BVD.
Multiple NSAIDS?
Often incidental finding at slaughter
What are some causes of abomasal ulcers
- Lactating dairy cows
- Stress of lactation
- High levels of grain
- Stressful events: transport, surgery, fractures
- Secondary to LDA, RDA, vagal indigestion
- Handfed calves: common at weaning
Describe the overall pathogenesis of gastric ulcers
Injury to gastric mucosa -> Diffusion of H+ ions into tissue -> Damage
Describe the 4 types of abomasal ulcers
Type 1: Non-perforating, minimal amounts of intraluminal haemorrhage
Type 2: major blood vessel perforation, severe blood loss, melena
Type 3: perforating ulcer, acute local peritonitis, peritonitis localised by greater omentum
Type 4: perforating ulcer, diffuse peritonitis
How does ulceration differ in cattle and calves?
In cattle - Fundic ulceration.
In calves - Pyloric ulceration
Describe the clinical signs of abomasal ulceration
Abdominal pain
Melena
Pale MM
Sudden onset anorexia
Tachycardia
If perforated - hypovolaemia, unable to stand
How is abomasal ulceration treated?
Antacids: 1st line.
- Magnesium oxide oral 800g /450kg daily
- Aluminium hydroxide oral 40g twice daily
Blood transfusion / fluids
- Haematocrit < 12%.
- 20ml / kg body weight.
- Shock fluids 10ml / kg / hr.
