SA GI Flashcards
What is the major clinical sign of acute gastroenteritis caused by surgical disease (eg FB, intussusception)?
Vomiting
What must you make sure to prevent when treating dogs with acute gastroenteritis?
Dehydration
Give some causes of acute gastritis
Dietary indiscretions Foreign material Hairballs (cats) Certain drugs Acute systemic disease
What is the difference between diarrhoea caused by enteritis vs colitis?
Enteritis: profuse foul-smelling diarrhoea, may be associated with acute vomiting, often flatulence
Colitis: frequent small volume diarrhoea, mucoid, excessive straining, may contain blood
Give some causes of acute enteritis
Dietary indiscretions
Garbage intoxication
Enteric infection
Give some causes of acute colitis
Garbage intoxication
Whipworms
Protozoa (Giardia, Cryptosporidia, Tritrichomonas-cats)
How common in acute colitis?
Fairly common in dogs, rare in cats
If treating diarrhoea symptomatically, how long should you wait before reassessing?
Reassess if signs persist for >48 hours
What diagnostic tests should you include when investigating diarrhoea?
Haematology Serum biochemistry Urinalysis Faecal exam (for parasites) Imaging
How do you diagnose and treat Trictrichomonas in cats?
One of the most common infectious causes of colitis in cats.
Diagnosis: wet-prep= dilute a small amount of faeces with saline solution and examine under microscope. Will look like a tear-drop.
Resistant to all common anti-protozoals. Ronidazole= only one that works, but resistance has been seen.
Which supportive treatments can you use when treating diarrhoea?
Discontinuation of drug/toxin Dietary restriction Anti-emetics Anti-diarrhoeals (Canikur, Pro-kaolin) Parasiticides
Which tests should you do if presented with a peracute crisis of diarrhoea?
PCV/TP Blood smear Blood glucose Blood urea Urinalysis
Which drugs are contraindicated when treating diarrhoea and why?
Corticosteroids and NSAIDs
They damage GI mucosa and the kidneys (if hypovolaemic)
When should you not give oral rehydration solutions?
If vomiting or severely dehydrated
Why should you feed through diarrhoea?
Reduces potential of sepsis
Speeds recovery
Give some categories and examples of anti-emetics
When are they safe to use?
Centrally-acting: Maropitant (‘Cerenia’), Metoclopramide, Chlorpromazine
Anti-cholinergics?: Atropine, Methylscopolamine
Only safe when obstruction is ruled out!
Which receptors does Maropitant work on?
What is the dose rate?
NK-1 receptor antagonist
Licensed for dogs
SID dosing: SC= 1mg/kg, PO= 2mg/kg
Few adverse affects or contraindications
When should you give gastric mucosal protectants?
Give some examples
Only if vomiting is persistant, or ulceration is present
H2-receptor antagonists (eg Cimetidine)
Sucralfate
Antacids (eg Al(OH)3)
How do anti-diarrhoeals work?
Give some examples
‘Protect’ mucosa by binding toxins and excess water.
Kaolin-pectin
Activated charcoal
Al(OH)3
Why might you give opioids to a dog with diarrhoea?
Slow rate of transit (decrease peristalsis)
Anti-secretory
Give some indications for treating diarrhoea with antibiotics
Haemorrhagic diarrhoea
Diarrhoea and pyrexia
Known infection (eg Salmonella, E.coli, Campylobacter)
Which antibiotic should you not treat diarrhoea with?
Neomycin (can cause diarrhoea as a side effect)
How can you remove a gastric foreign body?
Induce vomiting (if smooth object, recently ingested, or a non-corrosive poison) Natural passage (small objects with no sign of gastric disease; failure to pass within 48 hours -> surgery) Surgery
What can you give to induce vomiting?
Apomorphine
Xylazine
Which breeds are most affected by canine haemorrhagic enteritis?
Toy and miniature breeds
Which toxin is associated with canine haemorrhagic enteritis?
NetF enterotoxin
Give some clinical signs of canine haemorrhagic enteritis
Sudden onset vomiting +/- blood Followed by diarrhoea a few hours later Severe bloody diarrhoea Marked haemoconcentration Depression, shock High PCV (60-80) but normal skin turgor Bloods unremarkable
What is essential when treating a dog with haemorrhagic enteritis?
Prompt vigorous fluid therapy:
IV balanced electrolyte solition
80ml/kg/hr infused rapidly until CPR normal, and PCV <50
Then as needed to maintain PCV <50
How do you treat canine haemorrhagic enteritis?
IV fluids Withhold all food and water Parenteral broad-spectrum ABs Gut protectants Anti-emetics or antidiarrhoeals (?)
Give the categories of acute gastroenteritis
Non-fatal/self-limiting (eg dietary indiscretion)
Secondary to systemic disease (eg liver/pancreatic disease)
Severe potentially life-threatening (eg HGE, enteric infection, foreign body)
When diarrhoea or constipation be defined as chronic?
If it lasts over 2 weeks
Give some causes of chronic diarrhoea
Adverse reactions to food (true food allergy/food intolerance) IBD (tends to be immune-mediated) Antibiotic-responsive diarrhoea Lymphangiectasia Lymphoma/neoplasia Infectious disease (eg Giardia) (Partial) obstructions Systemic disease (liver/kidney/endocrine)
How would you do a colonoscopy?
Starve for 48 hours
Give poly-ethylene glycol: 3 doses, 4 hours apart, using stomach tube, followed by 2 warm water enemas
How can you treat large intestinal causes of diarrhoea?
Supplement fibre
Sulfasalazine (used for IBD and colitis)
Which tests should you do when investigating chronic diarrhoea (in order)?
Faecal analysis (parasites, bacteria) Haematology, serum biochemistry, urinalysis (systemic disease) Endocrine tests Imaging (radiography, US) Intestinal biopsy
In which 2 ways can you take an intestinal biopsy?
Endoscopy-minimally invasive, but requires equipment and expertise, and only gets a small superficial sample from a limited region
Exploratory coeliotomy- can get multiple full-thickness biopsies but surgical risk. Best for cats.
What would you suspect as the cause of chronic diarrhoea if an intestinal biopsy showed normal/mild inflammation?
Adverse reaction to food
AB-responsive diarrhoea
IBD
What would you suspect as the cause of chronic diarrhoea if an intestinal biopsy showed moderate-severe inflammation?
IBD
How do you treat IBD?
Steroids
Define constipation
Is it more common in dogs or cats?
Difficult, incomplete or infrequent evacuation of dry hardened faeces from the bowels
More common in cats
What would you suspect if an older cat developed constipation out of the blue?
Kidney disease
Give some causes of constipation
Dietary (low-residue diet; ingested foreign material eg hairs in cats)
Neuromuscular (spinal cord disease, idiopathic megacolon)
Environmental (obesity, inactivity, change in routine)
Colonic obstruction (stricture, pelvic trauma, neoplasia, FB)
Electrolyte imbalance (dehydration, hypokalaemia)
Drug-induced (opiates, phenothiazines, anticholinergics)
How does megacolon form?
End-stage of constipation, or result of neuromuscular dysfunction
Give the clinical signs of megacolon
Long-term difficulty defecating
Marked build-up of faecal matter, grossly-distended colon
How do you treat megacolon?
Surgery
What are the treatment options for constipation?
- Remove underlying cause if possible
- Oral laxatives eg lactulose (loosens faeces)
- Cisapride (pro-kinetic used in rabbits and cats that are heading towards megacolon, when there is poor muscle function. Unlicensed)
- Enemas (warm water enema, massage faeces out)
- Gentle manual evacuation under anaesthesia
- Surgery (if megacolon)
- Dietary management (high fibre diet; not effective in treatment of obstruction, but helps prevent recurrence)
