Flashcards in Diarrhoea Deck (49):
What affects acid release in the stomach?
- chemical stimulus from food (gastrin)
- stretch in lumen (gastin)
- parasympathetic NS (Ach)
How does gastrin affect acid secretion?
Travels via blood then acts via ccKb receptor on K+/H+ ATPase
What does vagal input do to GIT?
Increases tone so increases smooth muscle contractions - increase motility
4 ways to treat constipation
- lubricate (liquid parafin)
- form bulk (fibre - stimulate defecation)
- osmotic agents (Mg sulphate - stimulate defecation as distended)
- stimulant - irritant
two types of emetics
- stimulate vom centre (dopamine agonist)
- irritate gastric mucose (epsom salts)
two type of anti-emetics
- dopamine antagonist (metoclopramide)
- M1 and H1 antagonist ( diphenylhydramine)
5 types of gastro-protective and ulcer-healing drugs
- antacids (CaCo3)
- H2 antagonis (ranitidine)
- proton pump inhibitor (omeprazole)
-mucosal binding agents (sucralfate)
- prostaglandin analogues (misoprostol)
How do cows get metabolic acidosis from diarrhoea?
fermentation of starch and sugars in the hindgut produces H+ which pulls buffering ions into the lumen and are excreted.
increased problem with dia as stagnant food
and as hypovolaemic the kidney is under perfused so less able to buffer acid/base changes
Why don't you want to give antibiotics to young calves with diarrhoea?
can affect the developing GIT flora and will create problems later on
How do rotavirus / coronavirus result in diarrhoea?
they are activated by int. proteolytic enzymes
attack ep cells of SI causing desquamation and reduction in absorptive capacity and secretory defence mechanisms
so get dia loosing water, sodium, chloride, bicarb
How does ETEC cause diarrhoea?
uses F5 Ag to adhere to mucosa brush border and produces a heat labile toxin (enterotoxin) that causes hypersecretion of fluid into the gut causing rapid dehydration, collapse and death. (also produces heat stabile toxin)
Why is ETEC more commonly found in very young calves?
At a week old receptors in the GIT to ETEC toxin are covered by mucus
in adult horses where does dia come from?
always colon +/- SI
never just SI
in a foal where can dia come from?
LI or SI
How is diarrhoea in horses classified?
1) animal age
2) duration of signs
3) history -risk factors
What are the most common causes of diarrhoea in foals upto 3/4 MO?
- foal heat dia ( 7-10d old as starting to eat roughage)
What are the most common causes of diarrhoea in older foals upto 10-12 MO?
- parasitic (strongylus, culgaris, cyathostomins)
- proliferative enteropathy (lawsonia intracellularis (at weaning -7m))
What are the most common causes of diarrhoea in adult horses?
Signs of acute diarrhoea in horses
Causes of acute diarrhoea in horses?
When is diarrhoea chronic in the horse?
after about 2 weeks, animal is coping
Common causes of chronic diarrhoea in horses?
3 main principles of therapy for diarrhoea in horses?
endotoxaemia prevention / treatment
specific treatments for cause
What is endotoxaemia? and what are the associated signs?
when endotoxin from a G-ve bacteria enters the blood stream through a damaged mucosal barrier -
interacts with macrophages -
systemic infl ---
depression, tachycardia, tachypnoea, fever, colic, dai, hyperaemic toxix mucous membranes
How to diagnose endotoxaemia?
presence of band neutrophils
4 ways to treat endotoxaemia
1) prevent endotoxin entering circulation (remove inf bowel)
2) neutralise endotoxin before it interacts with infl cells (polymixin B or plasma with Ab)
3) prevent synthesis, release or action of infl mediators (flunixin)
4) prevent endotoxin induced cellular activation
Foal endotoxaemia - cause and treatment?
Normally from bacteraemia and sepsis so give antibiotics
Most common causes of diarrhoea in young calves?
What is ETEC ?
a strain that can cause enteric disease and villi stunting, metabolic acidosis, dehydration and electrolyte loss
common causes of diarrhoea in growing cows?
Common cause of diarrhoea in adult cows?
Johne's disease (MAP) ,
What is Johne's disease (MAP)?
mycobacterium avium paratuberculosis
lymphocyte and macrophage infiltration of the mucosa causing it to be grossly thickened
severe hosepipe faeces and weight loss
may be zoonotic
no cure so cull
What is melaena a sign of?
bleeding from upper GIT
what is dyschezia?
difficult or painful defecation (indicates colon obstruction)
what is heamatochezia?
fresh blood in stool (indicated colitis)
What is tenesmus?
ineffectual straining (colitis)
How is diarrhoea catagorised in the cat and dog?
acute / chronic
small / large intestine
Acute vs chronic diarrhoea in the cat and dog
Chronic = over 3 weeks
common causes of acute large bowel diarrhoea in the cat and dog?
How is small bowel acute diarrhoea in the cat and dog divided?
systemic / no systemic signs
Common causes of small bowel acute diarrhoea in the cat and dog without systemic signs?
common causes of small bowel acute diarrhoea in the cat and dog with systemic signs?
bacteria (salmonella, campylobacter)
viral (distemper, parvo, panleukopenia)
common causes of chronic large bowel diarrhoea in the cat and dog?
chronic partial obstruction
tritrichomonas foetus (Cat)
how is small bowel chronic diarrhoea in the cat and dog split?
common causes of small bowel chronic diarrhoea in the cat and dog - extra GI causes?
metabolic - hepatic disease, hyperthyroidism, addisons, renal insufficiency
pancreatic - EPI, chronic pancreatitis
common causes of small bowel chronic diarrhoea in the cat and dog - GI causes?
chronic partial obstruction
food responsive disease
Small vs large: (cat and dog)
volume - more with small
mucus - large
frequency - more in large
tenesmus - large
dyschezia - large
weight loss - small
vom - both
condition - worse with small
meleana - small
What is food responsive disease in cats and dogs?
diarrhoea improves with novel protein