Farm 3 Flashcards
What is vagal indigestion?
An extreme cause of atony involving the rumen, reticulum and abomasum due to interference with vagal innervation of the medial walls by peritoneal adhesions following FB penetrations. The rumen fills with fluid (saliva and drinking water) or in rare occasions gas.
What are the clinical signs of botulism?
Flaccid paralysis Recumbency Constipation Lack of tone in the tail Difficult prehension and mastication Difficulty ruminating and eructating
What are the clinical signs of tetanus?
Tonic spasm of the reticuloruminal musculature Raised tail Stiff movement Erect ears Degree of trismus Constipation
When is rectal prolapse most likely to occur?
Most often piglets and lambs, occasionally in calves; commonly associated with long-term colitis and/or diarrhoea, e.g. coccidiosis.
List 4 conditions of the abomasum
Left displaced abomasum (LDA)
Right displaced abomasum (RDA)
Abomasal torsion/volvulus (AV)
Abomasal ulceration
What is the pathophysiology of an LDA?
There is decreased dry matter intake at calving leading to high starch diet, hypocalcaemia, systemic disease, SARA and fat infiltration of the liver. This leads to decreased abomasal activity and a build up of fluid and gas in the abomasum.
Decreased rumen fill and increased space in the abdomen after calving also contribute.
How does a displaced abomasum lead to ulceration?
After the abomasum there is continued secretion of acid -> dilation -> increased intraluminal pressure -> mucosal damage -> ulceration
What are the risk factors of abomasal disease?
Things that decrease DMI around calving (over fat cows, poor calving management, periparturient disease, poor feed access/palatability)
Lack of long dietary fibre (decreased rumen fill)
Poor control of energy balance around calving
Sudden increased concentrate feeding at calving
Hypocalcaemia
Peak incidence in spring (may be due to lack of long dietary fibre in the grass)
What are the clinical signs of LDA?
Decreased yield (classically 5-10 ltrs)
Decreased feed intake (especially concentrate)
Poor rumen turnover
May be signs of underlying primary disease (e.g. metritis, mastitis)
May show mild colic (rare)
How is an LDA diagnosed?
Percussion auscultation producing a ‘ping’
Spontaneous abomasal noise on the left ‘tinkling’
Splashing/tinkling/ping on ballotment behind the last rib
ALWAYS look for underlying primary disease
May come and go ‘swinging LDA’
What are the 3 broad treatment categories for treating an LDA?
Conservative
Semi surgical
Surgical
How can an LDA be treated conservatively?
Roll the cow (cast onto RHS, slowly roll through dorsal recumbency, may do a brief stop/shake in dorsal recumbency)
May use oral propylene glycol, oral fluids/electrolytes, oral probiotics, systemic prokinetics, long fibre diet as well
What is the relapse rate of LDAs treated with conservative management?
~75-80%
But may be a good option while you manage underlying conditions
How can an LDA be treated semi-surgical?
The roll and toggle method
- Roll as for conservative treatment (+/- sedation)
- Insert toggles through a trochar into the abomasum while the cow is in dorsal recumbency
What are the 5 different surgical approaches for treating an LDA?
Paramedian approach Bilateral flank approach Right flank approach Left flank approach Laparoscopic
Describe a paramedian approach LDA surgery
Sedation and local analgesia
Open the abdomen to visualise the abomasum
Suture the abomasal fundus to the ventral body wall (partial thickness), often include the abomasum the closure of the muscle layer
Describe a bilateral flank approach LDA surgery
Requires 2 surgeons and a standing cow
Local anaesthesia (e.g. paravertebral) and skin prep
Paralumbar fossa incision on each side
Left surgeon – identifies and decompresses the abomasum with 16G needle and tubing, checks there are no adhesions, passes under the abdominal contents via the ventral midline to the right surgeon
Right surgeon – bkrings the abomasum to the right side and fixes it into place with omentopexy, pyloropexy
What is an omentopexy?
Used to fix the abomasum in place in LDA surgery
A continuous suture is put through the omentum and each end of the suture material is sutured to the muscle layer
What is a pyloropexy?
Used to fix the abomasum in place in LDA surgery
Put a partial thickness suture through the pylorus and suture to the muscle wall
Describe a right flank approach LDA surgery
One surgeon, cow standing
Paralumbar fossa incision on the right hand side
The abomasum is palpated by reaching behind the rumen onto the left side (may be difficult with short arms)
+/- abomasum deflated using a needle and tubing
The abomasum falls or is guided to the ventral midline
Abomasum is located and pulled up to the incision
Fixed into place with omentopexy, pyloropexy
Describe a left flank approach to LDA surgery
One surgeon, cow standing
Paralumbar fossa incision on the left had side
The abomasum is identified and a continuous suture line is placed into the fundus. The ends of the suture are left very long ~2m
Abomasum is decompressed if needed
Needle attached to one end of suture material and passed ventrally through abdomen (guarded!) and poked out through ventral body wall to assistant
Repeated with second needle, two ends of material secured on outside as abo repositioned
Describe a laparoscopic approach to LDA surgery
Various techniques, some involve rolling and some are done standing
How can LDAs be prevented?
Maximise DMI around calving/early lactation e.g. check for stress, correct diet and access
Transition diet: some but not too much concentrate, sufficient long fibre
Fresh calved diet: sufficient long fibre
Early lactation energy balance
Check milk fever control
Check incidences of other diseases (e.g. metritis, milk fever and dystocia) and association with LDA cases
What is the pathophysiology of a right displaced abomasum
There is abomasal atony leading to dilation of the abomasum. The abomasum then becomes displaced onto the RHS. Abomasum is susceptible to torsion when dilated.
What are the clinical signs of an RDA ?
Similar to LDA (decreased yield, decreased feed intake, poor rumen turn over, signs of underlying primary disease) but more sever
May show mild colic if torsion has occurred
How is an RDA diagnosed ?
Auscultation during percussion and ballottment
Similar sounds to LDA, but in a different location as the gas cap is more dorsal
What are the broad treatment categories for RDA?
Conservative
Surgical
How are RDAs conservatively managed?
This is first line treatment if no signs of torsion
Gastric motility modifiers (metoclopramide (unlicenced), Buscopan (little evidence and can’t be used in lactating cows), erythromycin?)
NSAIDs (meloxicam)
IV Ca
Dietary management – more long fibre
Why would you choose to treat an RDA surgically?
If there is significant colic, increased HR or conservative treatment fails
How do you surgically treat RDA?
Standing right flank approach
The abomasum is decompressed (best done by exteriorising and emptying, although tube can be used)
Check for signs of ulceration
Pyloropexy usually performed to prevent torsion
How does the prognosis of an RDA compare to the prognosis of an LDA?
RDA has poorer prognosis
When do cattle usually get abomasal torsion?
As a sequela of RDA – the RDA may not present until torsion occurs
What are the clinical signs of a abomasal torsion?
Similar to the signs of an RDA but usually more sever colic signs, increase HR (>80-100bpm), little faecal material in rectum, signs of circulatory compromise (low temp, pale mm, dehydration, poor pulse quality)
How is abomasal torsion treated?
Standing right flank laparotomy Empty abomasum as much as possible Identify and correct torsion (often several axes of torsion so may be very difficult) Perform pyloropexy and close Supportive treatment – fluids and NSAIDs
What is the prognosis for an abomasal torsion?
Guarded/ poor prognosis
What are the predisposing factors for abomasal ulceration?
LDA/RDA
Stress
Concurrent disease
Ingestion of soil/sand
What are the clinical signs of abomasal ulceration?
Mild colic, inappetence, pain on ballotment of the right ventral abdomen, melaena/ faecal occult blood, signs of peritonitis
Signs are often mild and self cure, even if the abomasum is penetrated the omentum may just seal it off. However may also cause sever signs (colic and poor production) and may be fatal.
How is abomasal ulceration managed?
Euthanasia (often advocated once melaena is established)
Surgery
Analgesia – care with NSAIDs as may be ulcerogenic
Antacids?
Antibiotics
What is the main threat to GI health in ruminants?
A fall in the rumen pH ‘ruminal acidosis’
If VFAs are produced faster than the cow can absorb the ruminal pH will drop
What is the aetiology of ruminal acidosis?
Carbohydrates produce acetic, butyric and propionic acid which is buffered by saliva. High carb diets that need little chewing produce a lot of acid and very little saliva so decrease the rumen pH.
