Farm Animal Final Year > Practical: Ruminant GI anatomy > Flashcards
Practical: Ruminant GI anatomy Flashcards
Label this?
Label diff stomachs?
Discuss these images of ruminant stomachs?
Label sheep stomachs?
Label sheeps stomach?
How do diff areas of ruminant stomach appear?
How does the flow of milk differ in the calf?
How does the ascending colon sit?
Discuss the ruminants colon?
What are in the diff parts of stomach?
Label this?
Label this?
Label this cow?
Label bovine stomach from left side?
Label the bovine GI from the right side?
Label ruminant liver?
Look at a LDA?
What characteristics of the abomasum have made LDA translocation possible?
- Attached to omasum and duodenum but is able to move
- Rumen is not attached to the body wall, so the abomasum is able to move between the two
- Not many structures obstructing path of displacement
- If rumen is full, then abomasum will be held in place, but if the rumen is smaller than usual, it will be able to float upwards.
- Abdominal viscera is rearranged in pregnancy, giving the abomasum opportunity to move
- Loose suspension by the greater and lesser omentum, so is able to move
- The condition is seen mainly in dairy cows in the first 4 weeks after calving
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Clinical signs of LDA?
Clinical signs: depressed, drop in appetite and milk yield, ketosis signs (etones in blood, milk, breath and urine). In RDAS may show colic, high heart rate, diarrhoea
if a torsion occurs, animals can go downhill very rapidly showing signs of severe shock with cold extremities and extreme dullness.
Discuss LDA and RDA?
- In an LDA the abomasum moves from the right side to the left and becomes trapped between the rumen and left abdominal wall Stretching results in constriction of the entrance to and exit from the abomasum and it fills with gas.
- In an RDA the abomasum moves up the right abdominal wall and becomes trapped above the omasum constriction results in accumulation of fluid and gas. However in addition a RDA can also become twisted upon itself which results in more severe clinical signs consistent with abdominal pain (elevated heart rate and signs of colic). Right displacement is a more serious condition than LDA and recovery rates are lower.
What is diagnosis and treatment of LDA?
Diagnosis: further investigation is required to distinguish a displacement from a case of ketosis. Stethoscope auscultation over the abdomen looking for the presence of a pinging noise that sounds like a tap dripping into a steel bucket. The pinging noise is indicative of a gas-filled organ, which is almost certain to be a displaced abomasum.
Treatment:
Early cases- Rolling
Toggling
Surgery
With careful reference to the anatomy, what happens in a cow with bloat? How does this knowledge help you decide how to manage an emergency case of a cow with bloat using a trocar technique?
Bloat: The build up of gas in the rumen due to failure of eructation.
Two types:
Gassy bloat: Least common, occurs when the gullet is obstructed (often by foreign objects such as potatoes) or when the animal can’t burp (such as with milk fever or tetanus). Vagal indigestion is when they can’t eructate, this causes gassy bloat. Treatment of gassy bloat: Passing a stomach tube is the best treatment for gassy bloat. Once the gas has been released, the cause of the obstruction should be looked for. In a few cases a trochar and cannula punched through the side into the rumen will relieve gassy bloat when a stomach tube has not worked. But such cases are rare, and as the trochar provides a tremendous opportunity for introduction of infection, it should only be used as a last resort.
Frothy bloat:
which happens as the result of a stable foam developing on top of the rumen liquid, which blocks the release of the gas. It is highly seasonal with peaks in the spring and autumn. This is because the foam is formed by breakdown products from rapidly growing forages (particularly legumes such as clover and alfalfa). These increase the viscosity (stickiness) of the rumen fluid and prevent the small bubbles of gas formed by rumen fermentation from coming together to form free gas that can be belched off. o Treatment of frothy bloat: Trochinisation does not work. For frothy bloat, antifoaming agents that disperse the foam should be given by stomach tube such as dimethicone or polaxolene. If an outbreak of frothy bloat occurs all cattle on that pasture should be removed immediately and put onto a high fibre diet (hay or straw), and any cows showing bloating signs treated with an anti-foaming agent. The pasture should not be grazed for at least ten days.
Where would you find the reticular groove in a calf and what is its function? .
The oesophageal groove is present in newborn ruminants. It is a channel taking milk from the oesophagus into the abomasum, bypassing the rumen, reticulum and omasum
What is the reticular groove reflex?
Reticular groove reflex: When suckling groove reflex is stimulated and tube formed that directs milk from reticulum through reticularomasal orifice, down omasal groove into abomasum
Why is it important and what stimulates it?
Milk going into rumen causes diarrhoea as is it is broken down into lactic acid which changes the pH and causes problems with microbes present
Sight, smell, suckling stimulates it
In year 2 you thought about a horse with impacted colic during one of your clinical relevance sessions. Can you identify where these sites are? What are the common sites of impaction in a horse with colic? ·
Ileal Impaction: The ileum is the terminal (last) three feet of the small intestine. Ileum and ileocaecal junction Ingesta (food material) can become blocked at this site causing a build up of gas and fluid in front of it and subsequent signs of colic Causes in the UK include a heavy tapeworm burden (swelling of the ileocaecal junction).
Pelvic flexure impaction: The pelvic flexure is a hairpin bend in the large colon where the intestine undergoes a marked reduction in diameter. Impaction between left ventral and left dorsal colon – at point of pelvic flexure due to the change in diameter. This type of colic is more common during the winter months (when horses are likely to be kept stabled for longer) and in horses that undergo a sudden increase in time spent stabled e.g. due to injury. Poor dental care may also be associated with this type of colic
Sand Impaction: Large intestine- pelvic flexure and right dorsal colon common sites. Sand accumulates in the large intestine of the horse. This is more common in certain geographical regions where the soil is sandy in nature and in horses that have been grazing on relatively bare pastures or have been turned out to eat food on sand arenas. It is more common in the autumn months, but can occur at any time of the year
What happens anatomically in a horse with colonic torsion?
A torsion occurs when parts of the gut rotates around the place where the gut attaches to the abdominal wall and subsequently cuts off the gut’s blood supply.
This is one of the most severe and rapidly fatal forms of colic.
The large colon is massive in size in the horse and unfortunately is poorly designed, as it is fixed in place only at its base. This can allow the large colon to rotate (twist) around the base cutting off the blood supply.
Horses at greater risk include brood mares, particularly after foaling, change in diet and poor dental care.
Rotation of the intestine causes the blood supply to this large part of the horse’s intestinal tract to be disrupted.
The severity will depend on how much the gut has rotated and how long blood supply to the colon has been compromised
