small mammals 4 - Diseases of Rabbits Flashcards
GI Stasis Syndrome or Dysbiosis - which smal mammals are susceptible?
Rabbits (and Hystricomorph rodents)
GI Stasis Syndrome or Dysbiosis - etiology
- Indigestible fiber stimulates intestinal (cecocolic) motility
- Lack of fiber, due to dietary deficiency or anorexia (e.g., stress, pain, disease), causes GI stasis
- Accumulation of ingesta in the stomach; fluid is absorbed
- Causes pain → further anorexia → cycle continues
GI Stasis Syndrome or Dysbiosis outcome
Result
* GI stasis disrupts the balance of cecal microflora → enterotoxaemia, intestinal gas distension, diarrhea, end-stage ileus, and death
GI Stasis Syndrome or Dysbiosis - specific causes
- Dental disease
- Antibiotic-associated enterotoxaemia – G-ve and Clostridium overgrowth
Gastrointestinal (GI) stasis summary
Gastrointestinal (GI) stasis is a syndrome of reduced or absent GI motility and its consequences.
* It is often caused by an inappropriate diet. Stress is a common initiator.
* It can rapidly become life-threatening.
The Role of Fiber
* Indigestible fiber stimulates intestinal (cecocolic) motility.
* Lack of fibre, due to dietary deficiency or anorexia, causes GI stasis.
* This results in the accumulation of hair and ingesta in the stomach; fluid is
absorbed.
* Compacted ingesta causes discomfort, contributing further to anorexia,
exacerbating GI hypomotility, and impaction of the stomach.
The Effect of Diet and Cecocolic Motility
* Cecal bacteria are vital for processing fiber entering the cecum into digestible nutrients, which are then reingested as cecotropes.
* An inappropriate diet or GI stasis can disrupt the balance of this complex cecal microflora and the environment in which it grows.
* Changes in cecal pH cause an increase in pathogenic bacteria, such as Clostridium and coliform species, resulting in enterotoxaemia, intestinal gas distension, diarrhea, end-stage ileus, and death.
GI Stasis Syndrome or Dysbiosis Clinical Signs
- Alert and quiet
- Anorexia
- Lack of fecal production
- Large/doughy stomach
- Decreased or absent gut sounds
- Tympanism, gas in GI tract
- Gastrointestinal pain
- But NOT a diagnosis
GI Stasis Syndrome or Dysbiosis
- History and Clinical Signs
- Diets of unlimited, good-quality, high-fiber grass or timothy hay, a moderate amount of fresh leafy greens, minimal pellets, and no or only occasional treats, are recommended.
- Stress alone, including stress caused by pain or concurrent disease, can cause GI stasis.
- The most common presenting complaint is a gradual decrease in appetite over 2 to 7 days and a subsequent decrease in fecal production.
- Also, a decrease in water intake; scant, dark, dry, and small feces; decreased activity; and signs of pain.
GI Stasis Syndrome or Dysbiosis
- Physical Examination Findings
- Generally, appears alert and quiet.
- Stomach contents feel firm, doughy, and remain pitted on compression.
- Little or no feces are palpable in the colon.
- Decreased or absent gut sounds.
- Contrast with obstructive disorders.
GI Stasis Syndrome or Dysbiosis
* Initial database for stabilization/clinical endpoints
- Blood pressure (reliable to diagnose hypotension on the front limb)
- Pulse, heart rate, CRT
- Body temperature
- Blood gases (collect enough blood for CBC and biochemistries, if possible)
- Urine specific gravity
GI Stasis Syndrome or Dysbiosis
* Rabbits – Bad Prognostic Indicators
- Hypothermia (<38oC, for each 1oC lower, odds of death x 2)
- Hyperglycemia (>20 mmol/L)
- Hypochloremic metabolic alkalosis suggestive of obstruction
- High lactates (>20 mmol/L),
- Hyponatremia (<129 mmol/L)
- Hypotension (<80 mmHg on Doppler, front leg)
- Hypoxemia (PvO2<30mmHg, SvO2<50%, SpO2<90-94)
GI Stasis Syndrome or Dysbiosis
- how do we stabilize?
- IV/IO catheter – crystalloid +/- norepinephrine (if no response/sepsis)
- If needed – heat, O2, dextrose, Ca, quiet
- Opioid analgesic
- If sepsis/enterotoxemia – IV enrofloxacin/ metronidazole antibiotic +/- biosponge
- If gastric obstruction – emergency surgery
GI Stasis Syndrome or Dysbiosis
- what to do once stable?
Investigatecause
* CBC and biochemistries, urinalysis, culture
* Imaging – x-ray/CT, US * Other…
diagnostic tests for GI Stasis Syndrome or Dysbiosis
- what will we see?
- CBC and chemistries unremarkable other than dehydration.
- Radiographs help differentiate GI stasis (compact, ingesta-filled stomach)
from obstructive disorders (dilated, fluid-filled). Moderate to severe gas distention of the cecum and scant fecal pellets are commonly seen.
GI Stasis Syndrome or Dysbiosis treatment
- Rehydrate the patient and stomach contents, alleviate pain, provide
nutrition, and treat any underlying disorders. - Most rabbits will begin to eat and pass stool within 24 to 48 hours of
treatment. - Continue treatment for 3 to 5 days.
<><><> - Underlying cause
- Most medical
GI Stasis Syndrome or Dysbiosis
- treatment reginmen for mild case
Mild:
* SC fluids
* Ranitidine – motility enhancer, gastric protectant
* Opioid: hydromorphone or buprenorphine
* Meloxicam PO
* Metronidazole PO
* Syringe feeding q8h
* If possible, exercise
