Bovine GI Disease Flashcards
What are 4 abomasal diseases of importance in dairy cows?
Displacements, Ulceration, Impaction, Neoplasia
What is the most common surgical procedure in dairy practice?
Surgical correction of left-sided abomasal displacements
Which DA can you let the sun set on and which one can you not? Why?
Sun can set on an LDA, but an RDA is urgent because it can progress to a life-threatening right-sided abomasal volvulus.
At what stage of the lactation cycle are DAs most common?
Early lactation
What are thought to be the 3 main contributors to DA risk in dairy cattle?
1) Excessive volatile fatty acid
production due to dietary factors –
negatively impacting abomasal motility.
2) Concurrent disease – hypocalcemia,
endotoxemia, etc. contributing to GI
stasis.
3) Genetic factors – body conformation.
Why is it not advised to treat an LDA with casting only?
High rate of LDA recurrence.
How is a cow “casted” or “rolled” for an LDA?
Cow is placed on her right side and rolled clockwise as viewed from behind.
How are DAs treated generally?
Surgically plus treatment of primary metabolic disease if present and stabilization for RDA with volvulus (volume support with fluids).
In what cattle populations are abomasal ulcers common? Uncommon?
Common in adult dairy cows and calves, rare in adult beef cattle.
In what stage of the lactation cycle are abomasal ulcers most clinically signficant?
Early lactation (first 4-6 weeks)
What dietary factors predispose dairy cows to abomasal ulcers?
-Highly fermentable, acidogenic diets (high moisture corn, corn silage)
predispose development of abomasal ulcers during early lactation.
-More common in component fed herds than in TMR fed herds.
What are 2 common conditions predispose adult dairy cows to abomasal ulcers?
1) Concurrent abomasal conditions such as abomasal displacements which lead to
pooling of highly acidic abomasal contents predispose to mucosal damage.
2) Common post parturient diseases (hypocalcemia, ketosis, metritis, etc) also
predispose to abomasal ulceration.
What causes abomasal ulceration in calves?
In calves, most clinically significant abomasal ulcers occur as a secondary complication to primary conditions such as calf diarrhea and enzootic calf pneumonia.
What neoplasia can cause abomasal ulceration?
BLV-associated abomasal lymphosarcoma
What is an iatrogenic cause of abomasal ulceration?
Overuse of NSAIDs
What are the 2 types of abomasal ulcers and what is the characteristic result?
1) Bleeding abomasal ulcer - melena.
2) Perforating abomasal ulcer - peritonitis
What type of ulcer is most common in calves? What is the typical finding associated with ulcers in calves?
Perforating ulcers, peritonitis.
What clinical signs characterize abomasal ulcers?
1) Bleeding ulcer - Melena, Pallor\Pale MM\Tachycardia, AFEBRILE
2) Perforating ulcer - peritonitis, FEBRILE, abdominal pain, death by sepsis in severe cases.
What are treatments for abomasal ulcers?
1) Bleeding ulcer - i) Dietary management –
remove all sources of highly fermentable feed and place the cow on a fiber only diet for 7-14days ii) Oral antacids iii) Transfusion should be considered if PCV falls below 15%.
2) Perforating ulcer - i) Dietary management – remove all sources of highly fermentable feed and place the cow on a fiber only diet for 7-14days
ii) Broad spectrum antibiotics– ceftiofur, penicillin or oxytetracycline for at least 7-14
days.
iii) Supportive therapy – fluids, especially for calves.
What would make you suspect abomasal neoplasia in an adult dairy cow?
If you identify melena in an adult
cow that is outside of the normal high risk period for the development of a
stress-induced ulcer (first 2-3 months of lactation).
What causes abomasal impaction in adult dairy cows? What are 2 predisposing environmental factors?
Secondary to vagal indigestion syndrome
1-Poor water availability
2- Sand bedding?
What is the prognosis for abomasal impaction?
Prognosis is best for calves and beef cattle with primary feed or foreign material impactions, and poorest for those cases that are associated with vagal indigestion.
Is flunixin meglumine used in abomasal ulcer therapy?
There is little to no place for flunixin meglumine in the management of abomasal ulcers, either of the perforating or bleeding kind in cattle, because of their ulcerogenic effects.
In what populations of adult cattle are abomasal impactions most common and under what circumstances?
Impaction of the abomasum is quite rare in dairy cattle, more common in beef cattle. Primary abomasal impaction can occur when individuals are fed poor quality very fibrous forages during the winter months, particularly if there is an inadequate source of fresh water available (such as following heavy snow fall in pastured range cattle).
Under what circumstances do adult cattle get esophageal obstruction? How important is the disease currently in the dairy industry?
Traditionally seen when cattle are fed root crops – beets, turnips, potatoes etc.
Exceptionally rare currently in both component fed and TMR fed cattle.
What are the clinical signs of esophageal obstruction in adult cattle?
1- Excessive ptyalism
2- Rumen bloat – free gas bloat due to an inability to eructate and can be life threatening.
3- Anxious behavior
4- Pain-standing with the neck extended and demonstrating greater than usual
resentment of neck palpation.
Why does pytalism lead to dehydration and metabolic acidosis in cattle?
Ruminants make huge amounts of saliva with lots of bicarb. If cattle cannot continually swallow this saliva (in the case of excessive ptyalism) they lose lots of water and buffer- leading to dehydration and acidosis.
What is the first step in addressing an esophageal obstruction in a cow?
Sedation with Xylazine (less commonly opioids or acepromazine)
How do you diagnose an espohgeal obstruction in a cow?
1) Sedate 2) Look for obstruction externally 3) If the obstruction is beyond the thoracic inlet, passage of a stomach tube will identify the level of obstruction.
How can you unblock a bovine esophageal obstruction?
Sedate and it may pass on it’s own. Manipulate manually into mouth or rumen
What should you use for lubrication while removing a bovine esophageal obstruction and why?
Use water, NOT MINERAL OIL. If the cow aspirates water, no biggie. If they aspirate mineral oil, they die.
What procedure may be performed in the case of an emergency esophageal obstruction?
Rumenotomy may be needed as an emergency measure to relieve life threatening bloat,
Why must one be cautious when using a stomach tube to diagnose/remove an esophageal obstruction?
Be exceptionally careful about overzealous use of force with a stomach tube – rupture of the thoracic esophagus is uniformly fatal.
What is likely to cause retropharyngeal trauma in cattle? What is NOT likely to?
A significant proportion of retropharyngeal
injury/trauma cases are the result of inexperienced lay people and the rough use of balling guns, specula, magnet retrievers, and oral pastes.
It is rare for retropharyngeal or esophageal trauma to be associated with coarse feed material or foreign bodies in cattle.
What are the clinical sigs of retropharyngeal injury in cattle?
-Moderate to severe pain on external palpation of the retropharyngeal
region.
-Swelling and edema of the retropharyngeal region (throat latch area) or cranial cervical esophagus.
-Excessive ptyalism
-Head and neck held in extension.
-Aspiration pneumonia may be seen.
-Rarely vagal nerve injury (vagal indigestion)
due to damage to the cervical vagus nerve.
How do you treat retropharyngeal trauma?
i) Broad-spectrum antibiotics,IV fluids and anti-inflammatories (NSAIDs)
ii) Nursing care including soft feeds such as gruels of alfalfa pellets or silage
What are some other terms for Rumen Acidosis?
grain overload, lactic acid
indigestion, toxic indigestion and rumen overload
What causes Acute Rumen Acidosis in cattle? What are the classic feed items involved?
Occurs in beef and dairy cattle when an individual or group of cattle gain sudden access to rapidly fermentable, starch
rich feedstuffs.
Classically associated with finely ground corn and wheat.
What is the general course of events in acute rumen acidosis cases?
Cows get into highly fermentable feed and will not…stop…eating. Rapidly broken down into lactic acid which cannot be metabolized by the cow. Rumen pH drops and once it gets low enough, most normal rumen flora will die.
What rumen organism is notorious for excessive production of lactic acid?
Streptococcus bovis.
What is the deal with isomers and acute rumen acidosis?
Carbohydrates are rapidly broken down in the rumen into both L and D isomers of LACTIC ACID. No mechanism exists for metabolism of the D ISOMER (there is one for L) so a severe D lactic acidosis develops.
What pH is at the lower end of normal in dairy cow rumen fluid and the point at which we become concerned for rumen acidosis?
pH = 5.5
At what rumen pH do most organisms die off? What organism is left?
pH = 4.5 - 5.0; Streptococcus bovis will persist.
Why is acute rumen acidosis a self-perpetuating problem?
As rumen pH drops, most organisms begin to die off, but the organism most responsible for making the problem acid (Lactic acid) will survive at low pH (Strep bovis) and make even more lactic acid.
