Smallies GI Flashcards
How does intestinal transit time of small herbivores differ to other hidgut fermenters?
Faster GI transit time to stay light and escape predators more efficiently
Can rabbits and rodents vomit?
No
What are the 2 forms of fibre?
Indigestible (stimulates gut, dental wear)
Digestable (fermented by bacteria to produce fatty acids)
How does the size of the thorax in small herbbivores compare with dogs and cats?
Much smaller - almost entire abdomen is gut contents
Why may the stomach be difficult to visualise on endoscopy?
Always food in the stomach
Where is the “pacemaker of the gut”?
Fusus coli - between proximal and distal colon junction
What to colonic contractions function to do?
Separate indigestible fibre -> produce >150 pellets per day, while digestable fibre washed back to ceacum for fermentation
When and how are ceacotrophs produced? What nutrients do they provide second time round? `
3-8 hours after eating, ceacum contracts, ceacotrophs produced coated in mucus
- provide microbial protein, B and K vits, FAs
Which animals still require external sources of B vitamins even if eating ceacotrophs?
Rodents
What may owners confuse ceacotrophs for?
Diarrhoea
Why are some antibiotics so dangerous to give to small herbivores?
- reduce some intestinal bacteria, allow overgrowth of others eg. Clostridium -> toxin production and death
Which antibiotics should NEVER be given to small herbivores
PLACE
- Penicillins
- Lincosamides
- Aminoglycosides
- Cephalosporins
- Erythromycin
What eception may PLACE antibiotics be given to small furries?
If given as injectables not orall y
Is gut stasis a disease?
No, clinical sign
What is gut stasis usually associated with?
Anorexia and dehydration - either as a cause or consequence
Give 7 causes of gut stasis
- Stress
- Pain
- Anorexia
- 1* GI disease
- Toxin ingestion
- Insufficient fibre
- Dehydration `
How is the problem of gut stasis defined, refined etc.?
Problem: complete or partial obstruction? +- anorexia?
System - 1* or 2* GI ?
Location: Proximal or distal GI ?
Lesion:? May not be investigated fully
What 3 aspects of the history are of particular importance when defining the problem of gut stasis?
- Husbandry history (Indoor/outdoor -toxins, predators, weather, FBs?)
- Diet (Probe! Owners will say what you want to hear)
- Medical history (DUDE?)
What 2 aspects of the physical exam may be slightly modified for small herbivores cf. dogs/cats
Otoscope for thorough oral exam
Listen to gut sounds like a horse
When would 1* GI disease be suspected?
- history of poor diet/change
- abnormality palpated in gut
- onset of gut stasis PREceded by signs of malaise (depression/anorexia etc.)
When would 2* GI disease be suspected
- history of stress
- obvious source of pain
What is the usual plan of action for an animal with gut stasis?
Admit for supportive care and diagnostics
- euthanasia may have to be considered
- ex lap if FB suspected
What are the 5 stages of stabilising a rabbit with gut stasis?
- warmth
- fluids
- nutrition
- gut stimulants
- analgesia
How can stress be decreased in the hospital setting?
Make as homely as possible - admit companion, bring in bedding etc.
What is the normal temperature of the rabbit?
~38-39.5c
Why can rabbit temperatures fluctuate so rapidly?
High surface area to volume ratio
What are maintainence fluid doses for a rabbit? How are these usually given?
<100ml/kg/day (high due to high metabolic rate)
- given IV/SC to reduce frequency
- if given SC: warm and add hyaluronidase (1500 IU/L) to decrease absorption/ distribution time
Where are IV catheters placed in the rabbit?
Marginal ear vein
After how long does anorexia present a problem/worrying situation?
12 hours
How much nutrition supplement is required to be syringe fed if completely anorexic?
50ml/kg/day
When may nasogastric tube placement be necessary?
Facial damage
Give 3 prokinetic drugs used to manage gut stasis. What are their dose rates?
- Metoclopramide 0.5mg/kg PO TID (or injectable)
- Ranitide 4mg/kg PO BID (or injectable)
- Cisapride 0.5mg/kg PO BID/TID
What is metoclopramide’s mechanism of action?
- Prokinetic due to Ach release, DA and 5HT Rs
- Works of oesophagus, stomach and SI
- Little/no effect on colonic motility
What is ranitidine’s mechanism of action? What is it most commonly used for?
- H2-Rs, also prokinetic due to Ach-esterase inhibition
- works on prox GI, MAY stimulate colonic motility too
> commonly used for ulcers
What is cisapride’s mechanism of action? How does it’s potency compare to metoclopramide and rinitide efficacy?
- works on 5HT-Rs to indirectly stimulate acetylcholine release
- works on oesophagus, stomach, SI and colon
- efficacy > metoclopramide, roughly = rinitidine
Should these drugs ever be used in combination?
Yes!
Why is gut stasis a potentially devastating problem?
Vicious cycle - pain -> gut stasis -> pain -> gut stasis…
Give 2 common analgesics used in small furries with dose rates
- NSAIDs - meloxicam <0.05mg/kg q6-8hrs
How do dose rates of common analgesics differ in small furries?
Higher doses /kg due to ^ metabolism
How do the side effects of analgesics measure up to the benefits?
Usually benefits outweigh the side effects BUT be aware of potential side effects (GI disturbance etc.)
- with NSAIDs ensure well hydrated and consider gastro-protectants
What should a normal survey radiograph of the GI tract in a rabbit look like?
- Food everywhere! normal
- Stomach should NOT reach caudal to last rib
How are initial radiographs of small furries carried out?
Concious - restrain with sandbags. If stressed retry later as can kick out and break back.
When would surgery be indicated in a small furry?
Obstruction: indicated by -
- visualisation of FB (May be soft carpet etc. so potentially not)
- gastric dilation
- gas shadows in SI cranial to obstructin
- serial radiographs show stationary gas bubble/obstruction
When are blood tests indicated?
Systemic disease suspected - renal failure - hepatic disease - Pb/Zn levels Glucose levels to indicate severity of condition
What should be considered before carrying out full oral exam and further imaging?
GA
Why may the “define the lesion” part of the logical approach not be completed in a gut stasis work up? WHen should it be investigated more thoroughly?
- GA may be contraindicated or not desirable
- Gastroscopy limited by permenantly full stomach
- Intestinal biopsies risk dihiscence and infection
> many cases resolve with symptomatic treatment only
> if recurrent episodes occour then investigate/work up further
What is the clinical workup approach to D+ in small furries?
Same as cats/dogs
- acute or chronic?
- if acute, with/without systemic signs?
- SI/LI/mixed?
What may owners confuse for diarrhoea?
Ceotrophs stuck to bum
Give 6 common causes of D+ in rabbits
- diet (new veg, too much fruit etc)
- antibiotics (just prior to death!)
- post weaning
- bacterial enteritis
- viral enteritis
- coccidiosis
Give 4 diagnositc tests to assess the casue of diarrhoea
- feacal parasitology
- feacal microbiology
- abdo imaging
- bloods
How does the stabilisation of a rabbit with diarrhoea differ to a rabbit with gut stasis?
Same steps but NO gut stimulants
- warmth
- fluids
- nutrition
- analgesia
How is D+ due to coccidiosis treated?
Toltrazil (3mg/kg PD SID for 2 days, repeat after 14d)
TMPS 30mg/kg PO BID
What can be given to bind enterotoxins?
Colestyramine
When would ABs be indicated?
Only in bacterial enteritis
- metronidazole 20mg/kg PO BID
Are probiotics advocated?
No evidence for but do no harm
