GI Clinical Flashcards
Disadvantage of parvovirus ELISA?
Can be false positive in a recently vaccinated dog (CPV-2 antigen)
Which clostridial toxins are most associated with disease?
A & B in C. difficile
CPE in Clostridium perfringens
Which E. coli species is associated with HUC? How is it tested for?
Enteroinvasive E. coli.
Test with FISH
What is the advantage of faecal flotation over a faecal smear??
It increases the sensitivity of detection. It is mainly useful for the detection of roundworm eggs and Giardia oocyts.
Folate digestion and absorption
Cobalamin digestion and absorption
What is alpha-1 proteinase inhibitor and when might measuring it be clinically useful?
It is a small (60kda) molecule that is similar size to albumin. It may be useful to measure it in cases where hypoalbuminaemia is documented but no other underlying cause has been found.
What T2M antibody level is consistent with a diagnosis of MMM?
>1:100
Sialadenitis vs. sialadenosis vs. necrotising sialometaplasia
Sialadenitis = inflammation of the gland
Sialadenosis = idiopathic non-inflammatory swelling of the gland. In some cases this will respond to phenobarbital.
Necrotising sialometaplasia = severe inflammatory swelling/necrosis of the salivary land
What breed is calvarial hyperosteosis seen in?
Bullmastifs - young, no treatment required.
What is fibrous osteodystrophy?
A sequalae to disrupted calcium homeostsis e.g. with renal secondary hyperparathyroidism. It may result in osteopenia, rubbery jaw and tooth mobility.
Most common oral tumours in dogs and cats
Dogs
- Melanoma
- SCC
- Fibrosarcoma
Cats
- SCC
- Fibrosarcoma
Which cranial nerves are involved in swallowing?
Trigeminal
Facial
Glossopharyngeal
Vagus
Hypoglossal
How does the distribution of oesophageal smooth muscle differ between dogs and cats?
In dogs the whole oesophagus has striated mucle whereas cats the distal 1/3 is smooth muscle only.
Which cranial nervve is mostly responsible for oesophageal innervation?
The vagus nerve.
Which breeds are predisposed to the following:
a) Pharyngeal weakness
b) cricopharyngeal achalasia
c) Muscular dystrophy
d) Inflammatory myopathies
e) Masticatory muscle myositis?
a) golden retrievers
b) cocker and springer spaniels
c) CKS and bouviour de flandres
d) Newfoundlands and boxers
e) Large breed dogs
Canine breeds with a congenital mega-oesophagus pre-disposition
Great Dane
German Shepherd
Labrador
Miniature schnauzer
Irish Setter
Chinese shar-pei
Newfoundland
Fox-terriers
Feline breeds with a congenital megaoesophagus breed predisposition
Siamese
What percentage of dogs with myasthenia gravis may have pharyngeal weakness as their only clinical sign?
1%
What is the pH range of refluxed gastric contents over which oesophagitis is more likely to occur/may be more severe?
pH <4 as pepsinogen is converted to pepsin at pH ragnes of 1.5-3.5
What adjunctive treatments to baloon dilation of an oesophageal stricuture can be performed?
Mitomycin C soaked gauze applied for 5 minutes prior to baloon.
Triamcinolone is injected into the submucosa. prior to dilation (this is a steroid)
Which breeds have have a familial predisposition to vascular ring anomalies?
Irish setters and German Shepherds
What are the most common oesophageal neoplasias in dogs vs. cats?
Dogs = fibrosarcoma
Cats = squamous cell carcinoma
Which breed is predisposed to congenital oesophageal fistulae?
Cairn terriers
Where are the following gastric endocrine cells found?
- Enterochromaffin like cells
- Somatostatin producing cells
- Gastrin producing cells
ECL = fundus, between gastric pits
SST = fundus, between gastric pits
Gastrin = antrum
What is the main stimulus for gastrin secretion?
Peptides and digested proteins in the stomach
What is the main stimulus for D-cell SST production?
Luminal acid
What is the molecular result of stimulation of the parietal cell to produce acid?
Increase in intracellular calcium leads to insertion of H+/K+ ATPase countertransporter and K+/Cl- cotransporter insertion into the luminal membrane.
Activation of adenlyl cyclase increases cAMP in the cell and protein kinases will increase activity of the ATPase.
Which prostaglandin has a negative affect on adenylyl cylcase in the parietal cell?
PGE2
Which GI hormone slows gastric emptying the most?
CCK
Which breeds are predisposed to hypertrophic gastropathy?
Drentse Patrijshond
Basenji
Shih Tzu
Which breed is predisposed to atrophic gastritis?
Norweigan Lundehund
Which breeds have a predisposition to GI neoplasia?
Belgian Shepherd
Rough Collie
SBT
Lundehund
Which acid base abnormality is associated with upper gastrointestinal obstruction?
Metabolic alkalosis with hypocholoraemia
Paradoxical aciduria occurs as the renal tubule resorbs HCO3 and Na and therefore loses H+ (due to the NHE). These mechanisms are an attempt to retain water.
Why might SST analogues be useful in treatment of gastric ulceration?
They inhibit gastrin production and ECL production of histamine
What unusual side effect has maropitant been associated with in young dogs and cats?
Bone marrow hypoplasia
Which dogs are predisposed to pythium?
Young, large breed dogs in the Gulf states of the USA.
What disorders of the stomach might increased globulins be seen in?
Basenji’s and dogs with fungal GI disease.
Stain for visualising spiral bacteria?
modified steiner’s stain
Stain for visualising fungi in the GIT?
gomori’s methianine silver
Stains for Eo, MC?
Eosinophils = siruis red
Mast cells - acion blue
What species are the following gastric worms present in and how are they treated?
Ollanus = cat, tx fenbendazole
Physaloptera = dog and cat, pyrantel, reservoir host is coyote. mostly in midwestern USA.
Treatment for Pythiosis
Surgical resection
Itraconazole + terbinafine
What is the main energy source for enterocytes?
Glutamine
What PAMPs are detected by the following receptors?
TLR 2
TLR 4
TLR 5
NOD2
TLR 2 = lipoproteins
TLR 4 = lipopolysaccharides
TLR 5 = flagellin
NOD2 = LPS
Which MHC type an enterocytes express?
MHC II
Which TH cell subtype is thought to play a major role in inflammatory enteropathies?
Th-17 who produce IL-17.
What do CD25Foxp3 T cells do?
Produce IL-10 i.e. are regulators of inflammation.
Where in the GI barrier do the following agents infect/invade?
Rotavirus
Coronavirus
Parvovirus
Vincristine
Rotavirus = villus tips
Coronavirus = mid-villus
Parvovirus = crypt
Vincristine = crypt
What are the different mechanistic classifications of diarrhoea?
- Altered motility
- Osmotic diarrhoea
- Secretory
- Increased permeability
- Mixed mechanisms
What are the pathogenicity mechanisms of the following E. coli organisms?
ETEC
EPEC
EHEC
AIEC
ETEC = enterotoxigenic –> secretory diarrhoea
EPEC = attacking and effacing –> SI or LI diarrhoea
EHEC = enterohemorrhagic –> associated with haemolytic uraemic syndrome
AIEC = attaching and invading –> GRANULOMATOUS COLITIS
What is the organism responsbile for salmon poisening called?
Neorickettsia helminthoeca
What type of hypersensitivities may be implicated in food allergies?
Type I, III and IV.
Which breed is predisposed to gluten sensitive enteropathy?
Irish setters
Which interleukin has been shown to be upregulated in feline IBD and lypmphoma?
IL-6
Which nerves innervate the colon?
Vagus = proximal colon
Pelvic = distal colon.
What transporter is responsible for potassium reapsorption in the SI?
K+/H+ exchanger.
What staining/histopathologic feature is characteristic of HUC?
Macrophage staining with periodic-acid-Schiff (PAS) under an ulcerated mucosa.
Where do the AIEC in HUC live?
Inside macrophage phagolysozomes.
Location of the emetic centre?
MEdulla oblongata
Location of NK1 receptors
Peripheral GIT, CRTZ and the NTS
DIfference in CRTZ receptors between dogs and cats?
D2 may be more important in dogs (hence apomorphines effect in this species)
Alpha2 may be more important in cats (hence alpha2 effect in producing emesis in this species).
How does the vestibular system influence vomiting in dogs vs. cats?
In cats there is a direct link between the vestibular system and the emetic centre, in dogs it is indirect through the CRTZ.
In which breed has a gluten-sensitive enteropathy been documented?
Irish Setter
Suspected to have an autosomal recessive mode of inheritance. Not documented in other breeds or cats.
Outline some Ddx for the lesions seen in the attached picture
The dog shows significant lingual and oral mucosal ulceration. While not an exhaustive list, potential causes of this ulceration include exposure to corrosive sub- stances, uremic stomatitis, autoimmune diseases such as systemic lupus erythemato- sus, bullous pemphigoid, and toxic epidermal necrolysis; other potential causes are local thermal damage, electrocution, and Candida infection.
