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