Conditions of the GI tract (Yr 4) Flashcards
what is ruminal tympany also known as?
bloat
what is ruminal tympany?
accumulation of rumen gas sufficient to change the contour of the rumen
what are the two types of ruminal tympany?
free gas (obstruction)
frothy (stable foam blocks gas release)
what are the clinical signs of ruminal tympany?
distended left hand side of abdomen (can progress to entire abdomen)
painful (inappetence, distressed, vocal)
respiratory distress
recumbency, death
what causes free gas bloat?
obstruction (foreign body, abscesses)
secondary to conditions that interfere with rumenoreticular motility (wire, vagal indigestion, milk fever…)
posture (if they are cast)
what can cause obstructions leading to free gas bloat?
foreign bodies
mediastinal abscess (secondary to chronic pneumonia)
what can effect the rumenoreticular motility, and lead to free gas bloat?
wires
vagal indigestion
tetanus
milk fever
what causes frothy bloat?
most commonly animals on pasture containing clover, alfalfa or lucerne
animals fed finely ground grain
why does clover, lucerne and alfalfa cause frothy bloat?
rapidly digestible in rumen which forms fine particles that trap gas bubbles
how is free gas bloat treated?
pass stomach tube
trochar (emergency)
chronic bloat - rumen fistula or red devil
treat underlying condition
what are the clinical signs of oesophageal obstruction?
bloat
inability to swallow
regurgitation of feed/water
drooling
where are the two main sites for oesophageal obstruction?
cervical oesophagus above larynx
base of heart/cardia
what are some treatments for oesophageal obstruction?
starve and observe (many self resolve)
sedate
buscopan
flunixin
manual removal or push down
how can you manually remove an oesophageal obstruction?
gag and try grab foreign body (get someone to push it up)
probang (cutting hook)
if you are unable to remove the oesophageal obstruction, what can you do?
trocharise to relieve rumen bloat
feed via rumen and wait for obstruction to pass
(risk of damage/necrosis)
how can frothy bloat be treated?
pass stomach tube or insert trochar then dose with surfactant (oils or silicone based commercial preparations)
can make incisions in emergency
what surfactants can be used to treat frothy bloat?
oil (vegetable oil)
silicone based commercial preparations
how can frothy bloat be prevented?
avoid high risk pastures at high risk times
buffer feed
restrict access (strip grazing)
administer antifoaming agents/sprays
remove animals with recurrent bloat
what are high risk pastures/times for frothy bloat?
early morning when pasture is damp
pasture with alfalfa, clover and lucerne
what is the typical history of a traumatic reticulitis case?
sudden milk drop
hunched appearance, stiff gait
inappetent
(often TMR fed)
where does the reticulum lie?
left hand side from 6th-8th rib
what is the rate of rumen/reticular contractions?
3 contractions in 2 minutes
what re the types of rumen/reticular contractions?
primary and secondary (2 primary to 1 secondary)
what is the function of the primary rumen contractions?
mixing cycle (first reticulum then rumen)
what is the function of the secondary rumen contraction?
eructation (rumen contractions start caudal and push gas towards cardia)
what tests are available for diagnosing traumatic reticulitis?
Eric williams test
withers pinch (abdominal pain)
pole test (abdominal pain)
faeces
white blood cell count
how is the Eric Williams test carried out?
listen over trachea, cow will grown when the rumen starts its primary contraction (will hear a grunt)
how is a withers pinch test done?
pinch withers and the animal will sink, if that is painful when you do it a second time they won’t dip
how will faeces likely appear if the cow has traumatic reticulitis?
stiffer with more long fibre as rumen isn’t able to turn over correctly so digestion isn’t as efficient
if there is pain on reticular contraction due to traumatic reticulitis, what will happen during the Eric Williams test?
3 scenarios…
grunt prior to primary contraction
reduced primary contraction
breath holding on primary contraction
what are the clinical signs of traumatic reticulitis?
sudden onset milk drop
increased temperature (39.5°C)
reduced rumen contractions
hunched up (adducted elbows)
inappetent, dull, depressed
(Eric williams test)
what are possible consequences of swallowing a wire?
reticulo-peritonitis… medial penetration can damage vagus (effecting motility)
pericarditis
other organ penetration
what happens if traumatic reticulo-pericarditis is left untreated?
cow goes into heart failure - jugular distention, jugular pulse, submandibular oedema (hopeless prognosis)
what is the procedure for an exploratory laparotomy, when looking for a traumatic reticulitis?
open cranially at left sublumbar fossa
exteriorise cranial rumen
pin rumen with sterile towel/claps
incise rumen reach hand cranially
locate reticulum
search for foreign body
what does the reticular wall feel/look like?
honeycomb
what does the rumen wall feel/look like?
lots of little papillae
what suture pattern is used to close the rumen?
Cushing or lembert (inverting suture patterns)
what is a common cause of vagus nerve injury?
complication of traumatic reticuloperitonitis
what do the clinical signs of vagus nerve injury depend on?
what part of the nerve is damaged…
dorsal vagus nerve - enlarged rumen/bloat
pyloric brach - abomasal impaction
what are some causes of damaged vagal nerve?
traumatic reticuloperitonitis
actinobacillosis of rumen/reticulum
fibropapillomas of cardia
late pregnancy
what is the typical appearance of a cow with vagal indigestion?
(10 to 4 appearance)
bloated
what are the typical clinical signs of vagal indigestion?
dehydration
enlarged rumen
scant faeces with undigested material
distended abomasum of lower right quadrant
hypermotility or hypomotility
what are some differential diagnoses for vagal indigestion?
chronic traumatic reticulitis
abomasal impaction (dietary origin)
omasal impaction
abomasal ulceration
what is the prognosis for vagal indigestion?
poor (slaughter)
what is the usually the primary event leading to a displaced abomasum?
abomasal atony caused by excessive VFAs in abomasum along with inflammatory cytokines inhibiting motility
what are some major risk factors for a displaced abomasum?
early lactation high yielding dairy cattle
fibre and concrete imbalance (SARA)
ketosis
hypocalcaemia
anything reducing DMI
how can a displaced abomasum be prevented?
nutrition (dry cow and lactating)
housing/comfort
preventing concurrent disease (endometritis, mastitis…)
what is an acceptable incidence level of LDAs?
1-2% per annum
what are the clinical signs of LDAs?
gradual milk drop or not reaching expected yield
ketosis
selective appetite (eating more fibre)
<4 weeks post calving
what are the differentials for a LDA?
vagal indigestion
peritonitis
bloat
why do you hear a ping when percussing a cow with a LDA?
there is a gas fluid interface
what ways can a LDA be treated?
rolling
toggling
how do you roll a cow with a LDA?
cast into right lateral recumbency (gas cap up on left)
roll to dorsal recumbency
roll to left lateral recumbency
percuss to see if ping has moved
(then feed good quality roughage)
what are the disadvantages of rolling to treat LDAs?
least successful
if abomasal ulcer is present it can rupture
what are the advantages of rolling to treat LDAs?
cheap and non-invasive
how do you toggle a LDA?
cast cow onto right lateral recumbency then roll into dorsal recumbency
percuss for ping on ventral midline
place trochar 15cm from xiphoid and 5cm from midline
place caudal toggle by pushing it down the trochar and clamping in place (smell to check its in place)
place cranial toggle 10cm cranial to the caudal one (again with trochar first)
tie trochars together
check gas is moving out of the right side
what are the advantages of a toggle?
cheap, quick, minimally invasive and simple
what are the disadvantages of toggles?
go in blind so can’t see if abomasal ulcers, adhesions…
fistula formation from suture
what are the types of surgical treatments for LDAs?
L and right sided (2 operators)
L sided (utrecht)
R sided
R paramedic approach (cast cow)
how is a bilateral flank LDA surgery done?
paravertebral analgesia
incision 5cm caudal to last rib
slide hands down wall of abomasum and shake hands
decompress abomasum (needle and flutter valve)
push abomasum to midline
pull abomasum up to right incision
omentopexy
why is a flutter valve used to decompress the abomasum during bilateral LDA surgery?
some abdominal content can flow out of the abomasum, having a tube ensures it doesn’t go into the peritoneum
how do you do an omentopexy during a bilateral LDA surgery?
identify the omentum next to pylorus (looks like a pigs ear) and suture that into the wound closure
how is the right sided surgical approach for LDA surgery carried out?
right flank incision
put hand over rumen and feel top of abomasum on left then release gas (flutter valve)
withdraw arm then follow right body wall down and under to identify the abomasum
grasp abomasum/omentum securely and firmly sweep down to pull abomasum to the incision
identify the pigs ear (and pylorus)and do an omentopexy
how is the left sided (Utrecht) method of surgery for an LDA carried out?
left sided incision
grasp greater curvature of abomasum or omentum
weave suture through omentum/abomasum leaving 2 very long ends
decompress abomasum (flutter valve)
place cranial suture thread through body wall around ventral midline
repeat with caudal suture thread 10cm behind the cranial one
reposition abomasum and tie sutures (ensure no small intestine are hooked in the suture)
how is a ventral abdominal paramedian LDA surgery carried out?
full GA/sedate
place cow in dorsal recumbency
line block around where you would place a toggle
incise
locate abomasum then suture to wall or surgical incision when closing
what post-operative care is required for LDA surgery?
antibiotics (pen/strep or oxytetracycline)
treat underlying condition (ketosis, endometritis)
high fibre diet
what happens during a RDA?
abomasum distends and displaces caudally to the right side
what is the metabolic sequelae of a RDA?
pooling of hydrogen and chloride in the abdomen due to upper intestinal obstruction can leads to a metabolic alkalosis and hypochloraemia
cytokine release and endotoxaemia
severe dehydration
why is the volvulus phase of RDAs problematic?
can lead to obstruction of the rumen emptying into the abomasum and cause ischaemic necrosis, veins occluded first so abomasal mucosa becomes swollen and friable
what are the clinical signs of a RDA whilst in the dilation and displacement phase?
inappetence/depressed
reduced faeces
dehydration
tachycardia, pale/dry MM
doughy rumen (outflow obstruction)
reduced rumen turnover
ping on upper right third
is a RDA has torsion as well, how may the cow present?
very systemically unwell
severe dehydration
what are some differentials for an RDA?
abomasal impaction
caecal torsion
traumatic reticulitis
intestinal obstruction
how can RDA dilation/displacement be treated?
medically - calcium, buscopan, fluids
surgically - drain/replace
what is the procedure for an RDA surgery?
open right flank
drain abomasum using a pipe
rotate abomasum and anchor pylorus
stitch up cow
what post operative care is needed for RDAs?
fluid therapy
NSAIDs
antibiotics
oral potassium chloride
calcium
propylene glycol
what are best preventative measure for RDAs?
good dry cow management/nutrition
what are some clinical signs expected with intestinal obstructions?
sudden milk drop
anorexia
ruminal stasis, no faeces
abdominal pain
what are some indication for surgery when presented with intestinal disease?
rapid deterioration
severe pain (poor analgesic response)
severe abdominal distention
absence of faecal output
high heart rate and blood lactate
what is the prognosis for intestinal diseases?
poor
what is the typical history/clinical signs of caecal dilation and volvulus?
dairy cow in first few months of lactation
inappetence, milk drop, ping in dorso-caudal right sub lumbar fossa
what is the aetiology for caecal dilation and volvulus?
excess carbohydrates bypass the rumen (due to acidosis) and ferment in the caecum
this creates VFAs and reduces the pH in the caecum leading to atony and accumulation of ingesta/gas
how can caecal dilations and volvulus be treated?
medically - good quality hay, hydration…
surgery - exteriorise and drain (only if there is torsion)
what can cause abomasal ulcers?
NSAID use
other diseases such as BVD
stress
acidosis
what is the pathogenesis of how gastric ulcers form?
injury to gastric mucosa leads to diffusion of hydrogen ions into tissues causing damage
how can gastric ulcers be treated?
antacids - magnesium oxide
blood transfusion or fluids
