Gastrointestinal Flashcards
(107 cards)
1
Q
Define Colic
A
A collection of clinical signs observed
interpreted as evidence of pain originating
from within the abdominal cavity.
2
Q
What may help you distinguish a normal, rolling horse to one rolling out of pain?
A
A normal, happy horse will get up and shake afterwards
3
Q
In what age of horses would you see parascaris equorum?
A
Less than 1 year
4
Q
What age of horses would you see Lawsonia intracellularis?
A
6 months - yearling
Or because Jamie has different shit on different slides - 3-7 months
5
Q
What is the normal temperature of a horse?
A
37-38.5 degrees C
6
Q
What is the normal HR of a horse?
A
36 +/- 10
7
Q
What is the purpose of nasogastric intubation?
A
- Asses for presence of fluid accumulation in the stomach
- Relieve stomach distention to avoid rupture and relieve pain
- Administer enteral fluid therapy if no reflux returned
8
Q
What action would you take if a horse presents with signs of colic and a HR or >60?
A
Immediately pass a stomach tube
9
Q
What structures may be palpated in the left dorsal quadrant when palpating per rectum?
A
Caudal edge of spleen
Nephrosplenic space
Nephrosplenic ligament
Left kidney
10
Q
What structures may be palpated in the right dorsal quadrant when palpating per rectum?
A
Caecal base
11
Q
What structures may be palpated in the left ventral quadrant when palpating per rectum?
A
Pelvic flexure of large colon
12
Q
What structures may be palpated in the right ventral quadrant when palpating per rectum?
A
Caecum
13
Q
What structures may be palpated at the dorsal midline when palpating per rectum?
A
Aorta
14
Q
What structures may be palpated at the ventral midline when palpating per rectum?
A
Female reproductive organs
Bladder
Small colon
15
Q
At what point do you take abdominal fluid from?
A
The most ventral part of the midline, possibly slightly to the right
16
Q
What aspects of abdominal fluid can be assessed?
A
- Colour
- Transparency
- Protein
- Cytology
- Microbiology
- Lactate analysis
17
Q
What is a normal abdominal fluid protein level and what does it mean when its elevated?
A
Less than 20 g/L, increase = intestinal injury
18
Q
What is lactate an indicator of and how is it interpreted?
A
Lactate is an indicator of tissue ischaemia and when peritoneal lactate is higher than plasma lactate it indicates the ischaemia is within the abdominal cavity.
19
Q
Which two sites may damaged intestine hide from leaking lactate into peritoneal fluid?
A
Epiploic foramen and inguinal ring (into scrotal sack)
20
Q
What are the four treatment goals of the colic patient?
A
Relieve pain
Restore tissue perfusion
Restore metabolic status
Manage secondary complications
21
Q
What is the onset and duration of action of flunixin?
A
15 minutes to onset, 12 hours duration
22
Q
Why is meloxicam in some cases considered superior to flunixin for treating colic?
A
It causes less retardation of the small intestinal mucosal repair after ischaemia.
23
Q
What side effects are seen with a2 agonists?
A
Decrease in GIT motility, CV and respiratory depression and ataxia.
Increased sweating and urine production, rarely xylazine rage
24
Q
When is N-Butylscopolammonium bromide indicated?
A
Spasmodic colic or with hypermotility.
25
How do you calculate the size of a horses stomach?
1.5% of its body weight
26
What is the use of dioctyl sodium succinate (DSS) and what can it not be administered with?
It reduces surface tesion and allows water and fate to penetrate the ingesta. It can not be administered with paraffin oil.
27
What is the triadan number for the left wolf tooth?
205
28
What is the triadan number for the last molar on the bottom right?
411
29
When do the deciduous incisors erupt in foals?
'01 ~6 days
'02 ~6 weeks
'03 ~6 months
30
When do a horse's permanent incisors erupt?
'01 - 2.5 years (in wear @ 3)
'02 - 3.5 years (in wear @ 4)
'03 - 4.5 years (in wear @ 5)
31
Which is the last permanent cheek tooth to errupt?
PM4 at 4 years
32
When to bottom incisor cups disappear?
'01 - 6
'02 - 8
'03 - 9
33
When do bottom incisor dental stars appear?
'01 - 8
'02 - 9
'03 - 10
34
What is the difference between and overjet and an overbite.
An overjet is rostral projection of the maxillary incisors while an overbite is rostral and ventral projection.
35
Is there any treatment for parrot mouth?
orthodontic braces +/- bite plate but only if done young. If not, will require life long dental care.
36
What are the 3 phases of eating
Prehension
Mastication
Deglutition (swallowing)
37
What drug predisposes to choke?
a2 agonist sedatives
38
What are the 4 main sites of oesophageal obstruction in horses?
Post pharynx
Thoracic inlet
Base of heart
Cardia of stomach
39
Discuss the diagnosis of choke
- Clinical signs
- Palpation
- Inability to pass a NGT to stomach
- Endoscopy
- Radiography +/- contrast
40
Discuss the treatment of choke
- Heavy sedation
- Stomach tube, lavage with water +/- obstetrical lubricant
- Oxytocin to stimulate smooth muscle contraction of distal oesophagus (efficacy?)
- Guaifenesin for skeletal muscle relaxation
- Withhold food and water
- IV fluids
- Correct electrolyte and acid-base abnormalities
- Anti-inflammatory medicine
- Antibiotics
- Surgery (rately required)
41
What do mucus cells secrete what is its function?
Bicarbonate rich mucus, protects the epithelium from acid
42
What do parietal cells secret and what is its function?
Hydrochloric, acid which activates pepsinogen
43
What do chief cells secret and what is its function?
Pepsinogen, which is activated by HCl to pepsin which aids in digestion of proteins
44
What do G cells secret and what is its function?
Gastrin, which acts to relax proximal stomach and enhance contractions in the distal stomach
45
In what portion of the stomach gets the majority of ulcers?
Squamous
46
Give examples of anti-ulcer drugs and their mechanism of action
Ranitidine - H2 antagonist
Omeprazole - proton pump inhibitor
Antacids - neutralisation
Sucralfate - reacts with HCl in stomach to form a protective barrier
47
What is the normal wall thickness of the equine small intestine?
Less than 2mm
48
What is the normal diameter of the equine small intestine?
Less than 4cm
49
Name a prokinetic drug for the treatment of ileus
lignocaine
| metaclopramide
50
Explain the clinical signs of Lawsonia intracellularis infection
Chronic weight loss due to malabsorption
Intermittent mild colic
Hypoproteinaemia - Oedema
US - thick SI
51
How do you diagnose Lawsonia intracellularis?
Serology
| PCR - Ileum (surgical collection) or fecal (not as good)
52
How do you treat Lawsonia intracellularis?
Antibiotics (Macrolides, tetracyclines) and supportive care such as colloid therapy for hypoproteinaemia
53
Outline the treatment of proximal enteritis
- REFLUX, indwelling NGT
- May require surgical decompression
- Prokinetics
- IV fluids (large volumes)
- Parenteral nutrition
- Anti-inflammatories
- Polymyxin B for endotoxin
- +/- Antibiotics
54
What age group of horses would you see inflammatory bowel disease?
Adult horses
55
What is inflammatory bowel disease characterized by?
Pronounced cellular infiltration of the small and large intestines.
56
What are the clinical signs of IBD?
```
Chronic wasting
+/- diarrhoea
+/- colic
Hypoproteinaemia
Anaemia
```
57
Which part of endotoxins is highly variable between bacteria serotypes?
O-specific chain
58
Which part of endotoxins is the toxic principle?
Lipid A
59
What are the main two organs which fail in the face of endotoxaemia?
Kidneys and laminae
60
What are the 6 main treatment strategies for endotoxaemia?
1. Inhibition of LPS release into circulation
2. Scavenging of LPS to prevent direct effect and interaction with inflammatory cells
3. Inhibition of cellular activity by LPS
4. Inhibition of mediator synthesis
5. Interference with effects of inflammatory mediators
6. Supportive care
61
How can you attempt to inhibit endotoxin release into circulation?
Antimicrobial therapy, however note that these kill bacteria and may increase endotoxin initially
62
How can you attempt to scavenge LPS in a horse with endotoxaemia?
- Immunotherapy (vaccination, anti-serum against LPS)
| - Polymixin B (binds to lipid A of LPS)
63
What portion of LPS does polymixin B bind to?
Lipid A
64
What side effect must be considered before using polymixin B
Nephrotoxicity
65
How may you attempt to inhibit cellular activation by LPS in a horse with endotoxaemia?
Ethyl Pyruvate blocks the production of proinflammatory mediators via blocking the activation of NF-kB
66
How may you attempt to inhibit inflammatory mediator synthesis in a horse with endotoxaemia?
- NSAIDs
- Pentoxifylline
- DON'T USE CORTICOSTERIODS
- Antioxidants (DMSO, Allopurinol)
- Lignocaine
67
What sort of supportive care would you be giving an endotoxaemic horse?
- Fluids
- CV support
- Manage coagulopathies
- Treatment/prevention of laminitis
- Nutritional support
68
What is the most important risk factor associated with adhesion in horses?
Recent abdominal surgery
69
What type of surgery predisposes horses to caecal impaction?
Musculoskeletal and opthalmology cases - high levels of pain
70
What are the clinical signs of caecal impaction
May be very mild and intermittent signs of colic, however rupture may occur with no significant signs of abdominal pain. Main signs are decrease fecal production and decreased borborygmi.
71
How is caecal impaction diagnosed?
Abdominal palpation per rectum will reveal a tight, ventral caecal band palpable on the right of the abdomen
72
What is the difference between primary and secondary caecal tympany?
Primary - rapid gas production or reduced caecal motility
| Secondary - outflow obstruction aboral to caecum (colon displacements)
73
What is the difference between primary and secondary caecal perforation?
Primary - broodmares after parturition w/o evidence of caecal outflow obstruction
Secondary - caecal outflow obstruction
74
What are the functions of the caecum?
Water reabsorption, electrolyte reabsorption and initiation of microbial digestion of complex carbohydrates
75
Explain the two parts of reperfusion injury.
Part 1 - Ischaemia
No oxygen -> no ATP -> Membrane ion pump function altered and mitochondrial dysfunction -> cell membrane failure and influx of Ca, Na and H2O -> Cell necrosis -> Reactive oxygen species and proinflammatory cytokines
Part 2 - Reperfusion
Leucocyte chemotaxis & activation -> ROS -> damage to cell membranes -> further necrosis -> proinflammatory mediators -> Vicious cycle
76
What are the first two organs that circulating toxins and inflammatory products reach after traversing the portal system?
Heart and lungs
77
What are the major implications of reperfusion injury?
Ileus, loss of absorption and increased secretion of the intestines. Endotoxaemia,
78
DMSO is available at 99% concentration. Is this fine to administer to a horse with endotoxaemia or reperfusion injury?
No, must be
79
How many taenia does each segment of the colon have and which have haustra?
```
Right and left ventral - 4 w/ H
Left dorsal - 1 no H
Right dorsal - 3 no H
Transverse - 2 no H
Descending - 2 w/ H
```
80
What are the functions of the colon?
Microbial digestion and fluid absorption
81
What may be heard on abdominal auscultation in a horse with sand impaction?
"surf sounds" in the ventral abdomen
82
How may sand impaction be diagnosed?
Fecal sand sedimentation
Ultrasound
Abdominal radiographs - need very high power
History and clinical exam findings
83
How may sand impaction be treated?
Treat primary large colon impaction first
| Then administer psyllium mucilloid and paraffin oil. May scald hind limbs, so protect with vaseline
84
How may sand impaction be prevented?
Remove access to sand
| Psyllium 1 cup in feed BID for 1 week per month
85
What may be seen on ultrasound with a left dorsal displacement / nephrosplenic entrapment of the colon?
Inability to identify the left kidney
86
What treatment can be considered for dorsal displacement of the colon?
```
IV fluids and withhold feed
Phenylephrine - alpha agonist
jog
GA and roll
Surgery - standing flank or ventral midline
```
87
What may be found on abdominal palpation per rectum in a horse with right dorsal displacement of the colon?
Gas distention, inability to locate pelvic flexure
88
Define peritonitis and list the ways it may be classified.
Inflammation of the mesothelial lining of the peritoneum, categorised as:
- Diffuse/localised
- Acute/chronic
- Septic/sterile
- Primary/Secondary
89
What is a normal amount of gastric reflux in a horse?
90
Why can there be an in an increase in serum GGT in horses with right dorsal displacement?
Direct pressure on common bile duct
91
Why must opioids be administed only with/after an a2 agonist?
Otherwise agitation and hyperexcitability is common
92
How many taenial bands does the descending colon have?
2
93
Small colon obstructions are strongly associated with what infectious agent?
Salmonella
94
When is an enema useful in a horse?
Only in foals :)
95
What are the factors that adversely affect surgical outcome of horses with discending colon obstructive disease?
- Poor blood supply
- High concentration of collagenase
- High intraluminal concentration of bacteria
- High musculat activity
- Presence of particulare faeces
96
Where do most rectal tears occur and why?
25-30cm from anus at 10-12 o'clock position because the thickness of circular muscle decrease and it is a weak area due to penetration of terminal arteries
97
Explain the grading of rectal tears
Grade 1 - mucosa and submucosa only
Grade 2 - muscularis only
Grade 3 - mucosa, submucosa and muscularis (serosa intact)
Grade 4 - mucosa, submucosa, muscularis and serosa (total tear)
98
Explain the types of rectal prolapse
Type 1 - prolapse of mucosa, submusosa
Type 2 - Prolapse of full thickness rectum
Type 3 - Prolapse of full thickness rectum and intusseption of rectum/colon
Type 4 - Intusseption through anus
99
How may you diagnose Clostridium perfringens?
PCR test for toxigenic strains, ELISA for extoxin. Large number of G+ive rods suggestive, faecal culture does not confirm disease - present in normal horses.
100
What age of horses are you most likely to see Clostridium perfringens in?
Often enterocolitis in neonatal foals with haemorrhagic diarrhoea and death, less commonly adult horses
101
How do you treat Clostridium difficile infection?
Metronidazole, vancomycin if resistant.
102
What part of the equine GIT is most sensitive to NSAID toxicity?
Right dorsal colon - wall will be thickened
103
What are the 5 mechanisms of weight loss in horses?
- Decreased intake
- Maldigestion/Malabsorption
- Inappropriate utilisation of absorbed nutrients
- Increased requirements
- Increased losses
104
Most significant diarrhoeal disease involves what part of the GIT?
Colon, may be SI in foals
105
What are the principles of treatment of horses with diarrhoea?
- Replace, maintain circulation volume
- Replace electrolytes
- Control endotoxinaemia & sepsis
- Binding of enterotoxins
- Control secondary consequences
- Nutritional support
- Re-establish normal GIT flora
106
Discuss fluid therapy for horses with diarrhoea
Replace deficit - kg x %dehydration
Maintenance - Adults 60mL/kg/day, Neonates 100mL/kg/day (I think)
Account for losses
107
How may you bind toxins in a horse with diarrhoea?
Activated charcoal, Bio-sponge
