GI Disease in Herbivorous Rodents Flashcards

1
Q

What is food selection in rabbits based on?

A

Food selection based on smell and vibrissae (long stiff hairs growing around the mouth or elsewhere on the face of many mammals, used as organs of touch; whiskers)

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2
Q

How are end products of digestion separated in rabbits GI?

A
  • End products of digestion are separated in proximal colon –> large indigestible fibre particles rapidly eliminated as hard pellets –> smaller particles passed to caecum for fermentation
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3
Q

Where does microbial fermentation occur in rabbits?

What happens after this?

A

Microbial fermentation in caecum –> caecotrophs –> ingested directly from anus and subsequently digested in a similar manner to other monogastric animals

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4
Q

When are caecotrophs usually passed in rabbits?

A

Caecotrophs usually passed overnight or early morning -> covered in protective mucus

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5
Q

What are the following:

  1. Sacculus rotundus
  2. Fusus coli
A
  • Sacculus rotundus at junction of small and large intestines
  • Fusus coli is a 8-10cm, specially adapted area of the colon –> acts as differential pacemaker –> alters depending on phase of faecal excretion
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6
Q

What is colonic motility regulated by in rabbits?

What can stress do to rabbits?

A
  • Colonic motility is regulated by the autonomic nervous system, prostaglandins and aldosterone
  • Stress of any kind –> adrenaline –> inhibits gastrointestinal motility –> GI stasis
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7
Q

What kind of diets are reccomended for rabbits and herbivorous rodents?

A
  • A diet high in fibre is essential
  • Natural diet –> mixed grasses, shoots, leaves, roots & bark
  • Chinchillas –> hold food in paws
  • Guinea pigs –> vitamin C
  • Selectively eat higher quality/calorific foods and prefer sweet- tasting foods
  • Recommended diet for pet rabbits _ 80-90% grass/hay, 1-2 tablespoons pellets, variety of leafy greens (preferably weeds)
  • Unable to vomit –> though do see clinically especially in guinea pigs and during anaesthesia
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8
Q

What are some causes of GI disease in Rabbits & Herbivorous Rodents?

A
  • In short, virtually anything can cause gastrointestinal disease!
  • Deficiencies in diet, husbandry and environment
  • Secondary to other diseases, pain and stress
  • Infectious organisms and toxins
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9
Q

What are some key points of the history of rabbits and herbivorous rabbits that you should check/ask?

A
  • Fully review the husbandry diet and environment
  • Hutch, house, free-range or combination
  • Access to grazing
  • Type and quantity of hay and how is it offered
  • Mix or pellets and how much is offered
  • Fresh produce offered and how much
  • Treats e.g. Yoghurt drops, seed sticks, biscuits…
  • Supplements, vitamin C (guinea pigs)
  • What is actually eaten
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10
Q

What should you check on the clinical exam of rabbits and herbivorous rabbits that you should check/ask?

A
  • Remember _ assess from afar 1st; good restraint!!
  • May require stabilisation, analgesia/sedation first
  • Thoroughly palpate and examine skull & mouth
  • Auscultate chest and abdomem
  • Palpate abdomen thoroughly but gently
  • Check body condition, limbs and perineum
  • Unkempt coat or ectoparasites may be due to obesity, orthopaedic or dental disease and/or inadequate husbandry –> may predispose to GI obstruction
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11
Q

What is ocular discharge usually due to in rabbits?

A

Ocular discharge is often due to molar disease. Chinchillas may often just wink

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12
Q

What is wrong with these 3 images?

A
  1. Faecal soiling
  2. Anal-rectal papilloma
  3. Matted fur on foot pads
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13
Q

What is the investigation for GI disease of rabbits and herbivorous rodents?

A
  • Haematology and biochemistry
  • Urinalysis
  • Faecal flotation & wet smear
  • Radiography
  • Ultrasonography
  • Endoscopy
  • Oral exam and abdominal palpation under heavy sedation/general anaesthesia when stable
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14
Q

How useful is haematology and biochemistry when investigating GI disease in rabbits and herbivorous rodents?

A

Haematology and biochemistry often non-specific

  • Commonly –> anaemia and stress leukogram
  • Hyperglycaemia –> stress, pain, advanced liver disease.
  • Hypoglycaemia –> starvation
  • Elevated TP & HCT +/- urea/creatinine indicate dehydration
  • Reduced albumin –> production/loss/ingestion
  • Liver –> TBIL, ALT, AST, GGT, ALKP
  • Urea –> circadian rhythm = higher in the evening
  • Lead –> toxicity most commonly occurs after chewing old painted woodwork
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15
Q

What is this?

A

Rabbit faecal smear demonstrating bacteria, yeasts (Saccharomyces guttulatus) and coccidia (Eimeria steidae)

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16
Q

Is this rabbit normal or abnormal?

What is it?

A

Normal (rabbit) lateral abdominal radiograph

‘hard faeces phase’

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17
Q

Is this rabbit normal or abnormal?

What is it?

A

Normal (rabbit) lateral abdominal radiograph

‘soft faeces phase’

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18
Q

What is wrong with this rabbit?

A

Lateral (rabbit) radiograph:

cardiomegaly and hepatomegaly

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19
Q

What is wrong with this radiograph?

A

Gastric Bloat

distension may be due to varying degrees of gas or fluid accumulation

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20
Q

What is wrong here in this guinea pig?

A

Gastric torsion in a guinea pig; a relatively common presentation that is often missed!!

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21
Q

What is wrong with this chinchilla?

A

Moderate gastrointestinal stasis in a chinchilla with dental disease

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22
Q

What is wrong in this chinchilla?

A

Severe gastrointestinal stasis in a chinchilla with dysbiosis after being treated with the antibiotic enrofloxacin

23
Q

What is wrong with this rabbit?

A

Caecal impaction in a rabbit

24
Q

What are some common causes of GI disease in Rabbits & Herbivorous Rodents?

A
  • In short, virtually anything can cause gastrointestinal disease!
  • Deficiencies in diet, husbandry and environment
  • Secondary to other diseases, pain and stress
  • Infectious organisms and toxins
25
Q

What are some conditions of the oral cavity in rabbits and herbivorous rodents?

A
  • Acquired Dental Disease
  • Dental caries
  • Tooth fractures
  • Jaw fractures
  • Foreign bodies –> wire, wood, grass awns etc.
  • Electrical burns –> chewing through cables
  • Congenital –> cleft palate, incisor malocclusion
26
Q

Acquired dental disease is progressive.

What are the 5 stages?

A
  • Stage 1 –> normal
  • Stage 2 –> root elongation & deterioration
  • Stage 3 –> acquired malocclusion
  • Stage 4 –> cessation of tooth growth
  • Stage 5 –> end stage:
    • (a) osteomyelitis and abscess formation
    • (b) calcification of teeth and surrounding bone
27
Q

What stage of dental disease is this?

A

Contrast study of NL-duct demonstrating obstruction

Stage 2-3 dental disease

28
Q

What stage of dental disease is this?

A

Stage 4 dental disease

29
Q

What stage of dental disease is this?

A

Stage 5a dental disease

30
Q

What stage of dental disease is this?

A

Stage 5b dental disease

31
Q

What is wrong with this guinea pig?

A

Guinea pig with molar disease and mandibular abscess

32
Q

What oesophageal disease is common in rabbits and herbivorous rodents?

A
  • Megaoesophagus and foreign bodies are rare
  • Gastro-oesophageal reflux and vomiting is in theory impossible but does rarely occur
33
Q

How common in gastric ulceration in rabbits and herbivorous rodents?

What is advisable?

A
  • Common –> secondary to anorexia and stress
  • Clinical signs vary from anorexia, bruxism and depression to acute-abdomen and shock
  • Routine administration of anti-ulcer drugs to anorexic rabbits is therefore advisable
  • Ranitidine and omeprazole most effective
  • Ranitidine is also prokinetic
34
Q

What commonly causes gastric bloat in rabbits and herbivorous rodents?

Prognosis?

A
  • Physiological obstruction –> gastric stasis as a result of pain, stress, dehydration, diet or toxins
  • Physical obstruction –> foreign body, neoplasia or adhesions
  • Subtle clinical signs may progresses slowly (physiological obstruction) or rapidly to an acute abdomen (physical obstruction)
  • Aggressive stabilisation required in all cases –> surgical intervention required once stable if does not respond to medical therapy alone
  • Prognosis is poor to grave, poor surgical patients
35
Q

What is enteritis as part of GI disease of rabbits and herbivorous rodents?

Clinical signs?

A

Enteritis (Bacterial)

  • Normal population –> Clostridia, Bacteroides, Enterococcus, Staphylococcus & E.coli
  • Dysbiosis –> overgrowth of clostridia and/or coliformes secondary to diet change, stress or antibiotic administration
  • Bacteroides appear to inhibit pathogenic bacteria
  • Lactobacillus are absent in rabbits (probiotics?)
  • Anorexia, diarrhoea, haematochezia, dehydration, shock and death
36
Q

What can cause bacterial enteritis?

A
  • E.coli _ Juvenile rabbits under stress
  • Salmonellosis
  • Pseudomonas
  • Yersinia pseudotuberculosis –> acute and chronic forms.
  • Latter = microabscess formation
  • Lawsonia intracellularis
37
Q

What can cause viral enteritis in rabbits?

A
  • Neonatal and juvenile rabbits
  • Coronavirus –> diarrhoea, abdominal distension and lethargy –> high morbidity and mortality
  • Rotavirus –> mainly diarrhoea
  • Concomitant infection with E.coli and/or coccidiosis

increases severity of clinical signs

38
Q

What can cause parasitic enteritis in rabbits?

A
  • Passalurus ambiguus (pinworm) is common
  • Rabbit is intermediate host for Cysticercus pisiformis, Coenurus serialis & Echinococcus granulosus
  • Coccidiosis (Eimeria spp) –> often subclinical except in juvenile rabbits under stress –> clinical signs include weight loss, diarrhoea +/- blood and in severe case –> death
39
Q

What are some miscellanious things that can cause GI disease in rabbits and herbivorous rodents?

A
  • Dysautonomia –> idiopathic –> clinical signs may include GI stasis, dry mucous membranes and conjunctiva, mydriasis, bradycardia, urine retention, megaoesophagus, large intestine impaction. May be found dead with food impacted in mouth; also occurs in hares.
  • Mucoid Enteropathy –> idiopathic syndrome characterised by caecal impaction and large quantities of mucus in colon. Generally juvenile rabbits –> usually fatal
  • Caecal Impaction –? occasionally occurs in adult rabbits (cf. mucoid enteropathy). Aetiology is often unclear but may be secondary to stress or ingestion of substances such as clay cat litter _ Poor prognosis, a small number rabbits have responded well to prostaglandin treatment
  • Neoplasia –> papilloma, lymphoma, adenocarcinoma, squamous cell carcinoma…
  • Anal Impaction –> common in aged male guinea pigs
40
Q

What is wrong here?

A

Post-mortem of juvenile rabbit

Suffering From mucoid enteropathy

41
Q

What can cause hepatic disease as part of GI disease in rabbits and herbivorous rodents?

A
  • Lipidosis –> obesity, anorexia, and pregnancy are risk factors
  • Liver lobe torsion –> presents as acute abdomen or death; prompt diagnosis and surgery required
  • Coccidiosis (Eimeria steidae) –> weight loss, diarrhoea, ascites, jaundice and hepatomegaly; often older rabbits
42
Q

What are some general goals for the treatment of GI disease of rabbits and herbivorous rodents?

A
  • Restore circulatory volume
  • Restore gastrointestinal hydration
  • Eliminate pain
  • Prevent/treat ulceration
  • Restore gastrointestinal motility
  • Eliminate stress
  • Identify and treat underlying diseases
43
Q

What nursing and hospitalisation is essential for GI disease of rabbits and herbivorous rodents?

A
  • Good quality nursing is essential
  • Keep away from sight, sound and smell of predators, general noise and people
  • Hospitalise with cage mate(s)
  • Encourage owners to bring normal food and utensils (especially guinea pigs)
  • Ensure soft, dry bedding and plenty of fresh hay
  • Provide hide box
  • Gentle and patient restraint and handling
  • Hand and syringe feeding
  • Grooming and cleansing of soiling and discharges
  • Especially clear nasal discharges
  • Note faecal output –> type, consistency and size
  • Gentle abdominal massage
  • Allow to exercise daily if condition allows
44
Q

Patient is stable, active, alert and swallowing

What is the treatment protocol?

A
  • Warm, quiet environment with plenty of hay, greens and favourite food items
  • Analgesia (opioid & NSAID)
  • Subcutaneous and oral fluids
  • Prokinetics & antacids
  • Assist feeding
  • Gently massage abdomen and allow exercise
45
Q

Patient depressed, dehydrated and/or unwilling to swallow

What is the treatment protocol?

A
  • Warm, quiet environment with plenty of hay, greens and favourite food items
  • Analgesia (opioid)
  • Intravenous/intraosseous fluids –> S/C & oral fluids
  • Prokinetics & antacid (Ranitidine)
  • Antibiotics ?
  • Assist feeding (NG tube if unwilling to swallow)
  • Gently massage abdomen
46
Q

Your patient has gastric bloat

What is your treatment protocol?

A
  • Critical patients!
  • Intravenous crystalloids and colloids
  • Analgesia and sedation (be prepared to intubate!)
  • Decompress with orogastric tube SLOWLY _ CARE very easy to rupture!
  • Administer liquid barium before remove tube and take lateral radiograph
  • Proceed as per general protocol 2.
  • Simethicone?
  • If bloat recurs or barium does not pass into small intestine → requires surgery
47
Q

What are some indications for surgery in Rabbits & Herbivorous Rodents?

A

Indications for surgery include lack of movement of barium from stomach and/or distension of small intestinal loop(s)

48
Q

Your patient has Dysbiosis/enterotoxaemia - what is your treatment protocol?

A
  • General protocol 2
    • Warm, quiet environment with plenty of hay, greens and favourite food items
    • Analgesia (opioid)
    • Intravenous/intraosseous fluids –> S/C & oral fluids
    • Prokinetics & antacid (Ranitidine)
    • Antibiotics ?
    • Assist feeding (NG tube if unwilling to swallow)
    • Gently massage abdomen
  • Colloids if hypotensive
  • Stop any offending antibiotics
  • Metronidazole +/- enrofloxacin?
  • Cholestyramine
  • Probiotics
  • Transfaunation of caecotrophs?
49
Q

What is the approach to Accumulated Caecotrophs?

A
  • Clip and clean perineum (often require sedation!)
  • Provide analgesia and antibiotics as required
  • Correct underlying causes e.g. husbandry, obesity, perineal folds, DJD, teeth
  • Exclude all treats, fruit and root vegetables from the diet
  • Provide ad-lib hay and grass
  • In stubborn cases can place on hay-only diet for 3 months (carefully monitor intake and weight); may not be appropriate if has oral/dental pain
50
Q

What is wrong here?

What is the treatment?

A
  • Faecal accumulation within excessive perineal skin folds
  • Treatment is relatively simple by resecting redundant skin
  • Weight management essential
51
Q

What are some problems of surgery in rabbits and herbivorous rodents?

Which suture material should you not use?

A
  • GI surgery in rabbits/rodents is often high risk
  • Adhesions form readily in rabbit
  • General principles and techniques as for cats
  • Precise, delicate and minimal tissue handling
  • Ensure tissues continually hydrated
  • No powdered gloves
  • Omentum small –> omentalisation is difficult
  • PDS, Vicryl, Monocryl –> DO NOT USE CATGUT
  • Verapamil reportedly reduces adhesions
  • Sodium carboxymethylcellulose solution reduces adhesions
52
Q

How should you perform dentistry in rabbits and herbivorous rodents?

A
  • Deep sedation/general anaesthesia IS MANDATORY
  • Good lighting +/- magnification (endoscopy helpful if available)
  • Mouth gag, cheek dilators, tongue depressors
  • Low-speed dental hand-piece with straight nose cone
  • Diamond cutting disc (incisors) variety of burs for molars
  • Avoid using hand-held rasps –> tend to be too traumatic
  • Skull radiography is essential → will miss > 80% pathology without!
  • Significant and very important species differences in anatomy & treatment!
  • Straight lateral, lateral oblique x2, dorsoventral and rostrocaudal views
  • Aim is to restore normal, pain-free occlusion as much as possible
  • Important not to lower crowns too far especially if molars stopped growing
  • Warn owners of need for multiple treatments
53
Q

What is happening in these images?

A
  1. Large tooth-related abscess
  2. Exteriorise and remove as much of abscess as possible including diseased teeth & bone
  3. Remaining abscess capsule is sutured to skin (marsupilised) to allow topical therapy on remaining abscess tissue