Bovine GI Disease Flashcards
1
Q
What are 4 abomasal diseases of importance in dairy cows?
A
Displacements, Ulceration, Impaction, Neoplasia
2
Q
What is the most common surgical procedure in dairy practice?
A
Surgical correction of left-sided abomasal displacements
3
Q
Which DA can you let the sun set on and which one can you not? Why?
A
Sun can set on an LDA, but an RDA is urgent because it can progress to a life-threatening right-sided abomasal volvulus.
4
Q
At what stage of the lactation cycle are DAs most common?
A
Early lactation
5
Q
What are thought to be the 3 main contributors to DA risk in dairy cattle?
A
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.
6
Q
Why is it not advised to treat an LDA with casting only?
A
High rate of LDA recurrence.
7
Q
How is a cow “casted” or “rolled” for an LDA?
A
Cow is placed on her right side and rolled clockwise as viewed from behind.
8
Q
How are DAs treated generally?
A
Surgically plus treatment of primary metabolic disease if present and stabilization for RDA with volvulus (volume support with fluids).
9
Q
In what cattle populations are abomasal ulcers common? Uncommon?
A
Common in adult dairy cows and calves, rare in adult beef cattle.
10
Q
In what stage of the lactation cycle are abomasal ulcers most clinically signficant?
A
Early lactation (first 4-6 weeks)
11
Q
What dietary factors predispose dairy cows to abomasal ulcers?
A
-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.
12
Q
What are 2 common conditions predispose adult dairy cows to abomasal ulcers?
A
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.
13
Q
What causes abomasal ulceration in calves?
A
In calves, most clinically significant abomasal ulcers occur as a secondary complication to primary conditions such as calf diarrhea and enzootic calf pneumonia.
14
Q
What neoplasia can cause abomasal ulceration?
A
BLV-associated abomasal lymphosarcoma
15
Q
What is an iatrogenic cause of abomasal ulceration?
A
Overuse of NSAIDs
16
Q
What are the 2 types of abomasal ulcers and what is the characteristic result?
A
1) Bleeding abomasal ulcer - melena.
2) Perforating abomasal ulcer - peritonitis
17
Q
What type of ulcer is most common in calves? What is the typical finding associated with ulcers in calves?
A
Perforating ulcers, peritonitis.
18
Q
What clinical signs characterize abomasal ulcers?
A
1) Bleeding ulcer - Melena, Pallor\Pale MM\Tachycardia, AFEBRILE
2) Perforating ulcer - peritonitis, FEBRILE, abdominal pain, death by sepsis in severe cases.
19
Q
What are treatments for abomasal ulcers?
A
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.
20
Q
What would make you suspect abomasal neoplasia in an adult dairy cow?
A
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).
21
Q
What causes abomasal impaction in adult dairy cows? What are 2 predisposing environmental factors?
A
Secondary to vagal indigestion syndrome
1-Poor water availability
2- Sand bedding?
22
Q
What is the prognosis for abomasal impaction?
A
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.
23
Q
Is flunixin meglumine used in abomasal ulcer therapy?
A
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.
24
Q
In what populations of adult cattle are abomasal impactions most common and under what circumstances?
A
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).
25
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.
26
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.
27
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.
28
What is the first step in addressing an esophageal obstruction in a cow?
Sedation with Xylazine (less commonly opioids or acepromazine)
29
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.
30
How can you unblock a bovine esophageal obstruction?
Sedate and it may pass on it's own. Manipulate manually into mouth or rumen
31
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.
32
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,
33
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.
34
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.
35
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.
36
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
37
What are some other terms for Rumen Acidosis?
grain overload, lactic acid
indigestion, toxic indigestion and rumen overload
38
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.
39
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.
40
What rumen organism is notorious for excessive production of lactic acid?
Streptococcus bovis.
41
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.
42
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
43
At what rumen pH do most organisms die off? What organism is left?
pH = 4.5 - 5.0; Streptococcus bovis will persist.
44
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.
45
What clinically detectable rumen characteristics are exhibited during acute rumen acidosis?
Early: free gas rumen bloat
Later: highly fluid-filled "splashy" rumen
46
What effect does acidosis have on rumen motility?
Causes complete rumen stasis.
47
How can acute rumen acidosis lead to toxemia?
Low pH -> huge die-off of rumen organisms -> release of LPS (endotoxin) into systemic circulation -> toxemia
48
How does rumen acidosis cause dehydration in cattle?
The excessive lactic acid within the rumen acts as an osmotically active
solute pulling fluid out of vascular and interstitial spaces into the lumen
of the organ – the cow dehydrates into her own rumen.
49
What is the effect of acute rumen acidosis on the rumenal mucosa?
The highly acid rumen contents cause a chemical/acid rumenitis,
damaging the rumenal mucosa.
50
What are the 3 causes of acidemia resulting from rumen acidosis?
1) metabolic acidosis due to excessive lactic acid production and absorption + lactic acid from poorly perfused musculature
2) poor peripheral perfusion (hypovolemia) 3) endotoxemia
51
What are clinical signs of acute rumen acidosis in cattle?
1) Completely off feed
2) Dehydrated (sunken eyes, protracted skin tent)
3) Tachycardic and tachypneic
4) Cool extremities
5) Precipitous drop in milk production
6) Large, fluid filled rumen
7) Initially scant watery feces, later profuse diarrhea
8) Untreated cattle become recumbent, comatose and die
52
What happens if you do not treat a cow with acute rumen acidosis?
Untreated cattle become recumbent, comatose and die
53
How is acute rumen acidosis diagnosed?
Missing feed + sick cows... "doesn't require Sherlock Holmes"
54
Why might rumen pH be HIGH in acute rumen acidosis cases?
1- A mild or moderate case 12-24 hours post-ingestion will not be acidic yet
2- If you obtain a rumen fluid sample by orogastric tube and your sample is contaminated by saliva (high bicarb concentration in cattle)
55
What are 2 ways to obtain rumen fluid for pH testing? Which way is more accurate?
Rumenocentesis or orogastric tube. Rumenocentesis b/c tube may be contaminated with high bicarb saliva and read artificially high.
56
What factors dictate treatment of acute rumen acidosis on a farm?
Dictated by ECONOMICS. May just send to slaughter instead of treatment. If you do start treatment, you will get drug residue issues that prevent use for food.
Even if animal survives, there are long term health sequelae.
57
What are the clinical signs that warrant immediate aggressive, in-hospital treatment of acute rumen acidosis?
Cattle with a rumen pH of less than 5, heart rates in excess of 100,
evidence of greater than 5% dehydration.
58
How are cases of severe rumen acidosis treated (most aggressive treatment)?
i) Rumenotomy – evacuate the rumen as and perform repeated high volume lavage
ii) Administer:
laxatives
antacids
rumen transfaunates
fresh hay (directly into the rumen)
parenteral calcium
intravenous fluids
sodium bicarbonate
59
How are moderately severe cases of rumen acidosis treated (less aggressive treatment)?
i) Instead of rumenotomy, pass a large bore stomach tube and attempt to siphon out
and/or lavage as much of the rumen contents as possible – repeated flushes
with 10-20 gallons should be attempted.
ii) Administer laxatives, antacids, rumen transfaunates, and parenteral
calcium
iii) High volume intravenous fluids should be given if possible
60
How are mild cases of rumen acidosis treated (least aggressive treatment)?
oral antacids, laxatives
and parenteral calcium
61
What are 3 sequelae to acute rumen acidosis?
1) Bacterial rumenitis with abscessation of the rumen wall
2) Hepatic abscessation, caudal vena caval thrombosis syndrome (CVCT)
3) Mycotic rumenitis, potential disseminated fungal disease with multiple organ involvement (liver, lungs, brain)
62
What therapies are NOT effective in treating acute rumen acidosis?
- Oral meds including penicillin to reduce numbers of Streptococcus bovis in the
rumen. Exquisitely sensitive to penicillin, but amount of rumen is so large that you can't really accomplish this orally.
- Oral activated charcoal. You can't get enough in there to be very effective in a cow
63
What are some herd-level issues that would make you suspect chronic rumen acidosis?
-Lower than anticipated production
- Increase in prevalence of common post parturient diseases
64
In what types of herds/herd nutrition is chronic rumen acidosis most common?
-Component fed
-Pastured
-Inadequate forage in diet
65
What disease does chronic rumen acidosis predispose a herd to?
Foot diseases due to association between chronic/subclinical rumen acidosis and laminitis.
66
What are 2 other terms for chronic rumen acidosis?
1- "SARA" SubAcute Rumen Acidosis
2- Subclinical rumen acidosis
67
Define bloat
bloat is defined as obvious abdominal distension causing the left side of the abdomen to be distended both dorsally and ventrally. In severe cases the right ventral abdominal quadrant will also be distended.
68
How do you distinguish rumenal bloat from ascites or pregnancy?
Rectal exam
69
What are 5 causes of acute, free gas bloat? Which are most and least common?
- Over ingestion of highly fermentable grain/concentrates (rumen acidosis)- COMMON
- Hypocalcemia/Milk fever- COMMON
- Obstruction (esophageal choke, neoplasia at cardia)
- Tetanus- UNCOMMON
- Inflammatory conditions causing vagal nerve damage (vagal indigestion) typically mix of free gas and frothy bloat.
70
What causes acute frothy bloat?
Usually associated with the sudden availability and over ingestion of lush green forages such as succulent alfalfa, other legumes or clover. Some genetic lines of cattle with larger rumen volumes and that produce specific salivary proteins appear to be more susceptible
71
What is the froth of frothy bloat made of?
Stable foam produced via fermentation of plant material that is higher in chloroplast membrane fragments and soluble protein
72
What causes chronic bloat in adult cattle?
Usually develops secondary to lesions of the vagal nerve
73
What are 5 causes of bloat in calves?
1- After feeding (resolves on own)
2- Management (inadequate calf starter, administration of antibiotics)
3- Older calves with insufficient fiber in diet
4- Sequela of severe bronchopneumonia and damage to vagus nerve
5- "Rumenal drinkers" Failure of reticular groove reflex or older cattle still on milk
74
How do you confirm diagnosis of rumen bloat in an adult bovine?
The diagnosis is usually obvious from the external appearance – but you should always confirm the diagnosis via a complete physical examination to include rectal palpation, and passage of a stomach tube.
Passage of a stomach tube allows distinction between free gas bloat and frothy bloat and is instantaneously diagnostic for obstructive lesions.
75
How is bloat treated?
-Free gas bloat: passage of stomach tube
-Frothy bloat: oral vegetable oil or poloxalene (Therabloat) to break surface tension and consolidate bubbles
-Must address primary disease!
76
When is use of a trochar advisable in bloat cases?
NEVER! Pass a tube or do rumenotomy surgery. Trochar use ensures peritonitis!
77
In what scenarios might you use a temporary rumen fistula?
Relief of chronic free gas bloat, especially in calves, when repeatedly placing a stomach tube is getting old.
In adults it can also be used as a means of relieving chronic free gas bloat or for enteral feeding of valuable cattle.
78
What is the most common cause of colic in adult dairy cattle?
Simple indigestion
79
Under what 2 circumstances is simple indigestion/colic most common?
First few weeks post-calving
Stressful situations, show cattle
80
What are 5 clinical signs of simple indigestion in cattle?
i) Non-specific – anorexia, reduced production, cold extremities, rumen hypomotility due to hypocalcemia.
ii) Colic of variable severity – can be
treading/teeth grinding or down, rolling
or kicking at the side.
iii) Tachycardia – this will be consistent with the degree of colic.
iv) Mild rumenal tympany (aka bloat) and right sided abdominal distension.
v) Rectal examination – no loops of
palpable small bowel.
81
How can you distinguish a colic case due to simple indigestion from a case due to small bowel obstruction?
RECTAL! If you feel loops of small bowel it is an obstruction. If it is unremarkable (aka no palpable loops of bowel detected) it is probably simple indigestion.
82
What is the standard treatment for simple indigestion?
1) Parenteral calcium borogluconate (25% 500 ml bottle SC)
2) Oral laxatives to purge bad feed – magnesium salts common. Prepare owner for inevitable diarrhea!
3) Analgesics – single injection of
flunixin meglumine for pain relief in very colicky individuals – do not use repeatedly
83
What is the pathophysiology of traumatic reticuloperitonitis?
1) Ingestion of penetrating, usually metallic foreign bodies in feed – nails, baling wire, debris, etc
2) Foreign objects usually get trapped within the “honey-combed” reticulum, sharp linear objects most likely to penetrate wall
3) Object penetrates the diaphragm into thoracic cavity -> septic pleuritis/pneumonia
4) Object can penetrate heart (lies against reticulum on other side of diaphragm) -> septic pericarditis
84
What are clinical signs of acute traumatic reticuloperitonitis?
Acute perforation associated with sudden, precipitous drop in milk and appetite.
Fever (103-105F), tachycardia, tachypnea
Signs of cranial abdominal pain due to localized peritonitis (resentment to pressure over the xiphoid and right ventral abdomen, excessive elbow abduction)
85
What are clinical signs of partial thickness/intermittent traumatic reticuloperitonitis?
Several days after perforation, partial thickness, intermittent perforation show subtle and challenging signs:
-partial anorexia
-moderate rumen hypomotility
-mild to moderate reduction in milk yield
-normal temperature, HR and RR
-Less obvious signs of abdominal pain and
resentment to palpation or withers pinch
86
Why does the sound of traumatic reticulopericarditis on auscultation change over time?
1) First week or so: Septic pericarditis “washing machine” sounds on cardiac auscultation bc pericardial lesion is still effusive
2) After 1 week or so: Fibrin deposition and
fibrous maturation of pericardial adhesions make heart sound muffled
87
What are 3 possible sequelae to traumatic reticuloperitonitis?
1) Septic pericarditis/pleuritis.
2) Reticular abscess formation
3) Vagal indigestion
87
How can you tell if a cow has a magnet from the exterior? What is a caveat to this technique?
A compass placed to the left elbow will deviate 90 degrees. But >1 magnet can interfere with each other, so deviation doesn't always mean no magnet/hardward disease.
87
How can hardware disease be prevented?
Administer magnets around 1 year of age
87
What is the most common treatment for hardware disease?
Most cases in practice are treated medically with systemic antibiotics, a magnet, and stall rest.
88
What is the characteristic appearance externally of a cow with vagal indigestion?
Papple shape
89
What are potential causes of vagal indigestion in cattle?
1- Traumatic reticuloperitonitis
2- Right sided abomasal volvulus
3- Abomasal ulcer perforation
4- Hepatic abscesses
5- Abomasal lymphosarcoma (pyloric outflow obstruction)
6- Abomasal impaction
7- Esophageal/pharyngeal trauma
8- Chronic bronchopneumonia/Thoracic vagal nerve injury
90
What is the most common cause of vagal indigestion in calves?
Chronic bronchopneumonia with subsequent damage to the vagus nerve
91
What findings would you expect upon rectal exam of a cow with vagal indigestion?
Rectal palpation reveals the ‘L’ or
‘V’ shape to the rumen
92
What are common clinical signs of vagal indigestion?
i) Gradual abdominal distension and development of “papple” shape.
ii) Some chronic cases demonstrate bradycardia.
iii) Rectal palpation reveals the ‘L’ or ‘V’ shape to the rumen.
iv) Other signs may be found that are
consistent with the inciting cause.
93
How is vagal indigestion treated and what is the prognosis?
Medical treatment with fluids,
catharctics/laxatives is often tried but
rarely works. Awful prognosis.
94
What neoplasia is common in young cattle? What clinical signs does it cause?
Papillomas/fibropapillomas of the distal esophagus, rumen and reticulum are quite common in young cattle and are usually clinically silent, unless they cause obstruction and bloat.
95
What metabolic condition in cattle can cause hepatic lipidosis?
Ketosis
96
What causes liver abscessation in adult cattle? In calves?
Adults: Acute or chronic rumen acidosis (aka grain overload)
Calves: Umbilical remnant infection
97
What types of bacteria cause hepatic abscessation in adult cattle? What is the most commonly found organism?
In general, gram negative opportunistic anaerobes. Most common is Fusobacterium necrophorum.
98
What is the pathophysiology of liver abscesses in adult cattle?
Rumenal acidosis -> Damage of rumen mucosa -> Portal blood has lots of bacteria -> embolic showering -> overwhelms liver capacity -> excess bacteria form abscesses
99
What diagnostic technique is best for detecting liver abscesses in cattle? What test is not generally useful?
Transabdominal ultrasound
Liver enzymes (GGT) normal or only slightly elevated- not good test
100
What is the most important sequela to liver abscesses in cattle?
Caval thrombosis syndrome
(CVCT syndrome).
101
What are the 3 syndromes associated with CVCT?
1- Sudden death
2- Acute respiratory distress
3- Hemoptysis (coughing up blood from lungs)/epistaxis
102
What are the pathophysiologies associated with the 3 types of CVCT syndromes?
1- Sudden death: rupture of abscess and injection of large amounts of pus directly into the caudal vena cave, death
2- Respiratory distress: Smaller volume of purulent material from ruptured liver abscess into caudal vena cava. Doesn't cause immediate death, but bacteria travel to lungs where they make abscesses. Abscesses discharge into the airway and cause respiratory distress and/or acute septic bronchopneumonia.
3-Hemoptysis/Epistaxis: purulent material in lungs blocks blood flow, aneurysm forms and eventually bursts, leading to hemorrhage. Can be slow and insidious or acute and dramatic.
103
What is a differential for a cow with sudden, large volume epistaxis of bright red blood?
Epistaxis due to CVCT (from hepatic abscesses)
104
What is the treatment for liver abscesses in cattle?
Not often treated unless high value/show cattle. Treated with long-term antibiotic therapy and aspirin.
105
What is the treatment for CVCT syndrome?
Rarely attempted or successful.
106
What herd-level issues are implicated when clinical cases of liver abscessation are identified?
Nutritional problems. Clinical cases indicate acute or chronic rumen acidosis is occurring with an insufficient or ineffective forage component in the diet.
107
In the US what are the 2 liver flukes of importance and what are their definitive hosts?
Fasciola hepatica- cattle and sheep
Fascioloides magna- white tailed deer
108
What is the size difference between the 2 liver flukes found in the US?
Fasciola hepatica are small and Fascioloides magna are big (can see on US)
109
In what parts of the US are liver flukes a significant problem in cattle?
Mild, wet climates like in the southern US (NOT Wisconsin)
