diarrhea in young eastern cottontails -...
TRANSCRIPT
11/4/2016
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Diarrhea in Young Eastern Cottontails
Renée Schott, DVM
Staff VeterinarianWildlife Rehabilitation Center of Minnesota
Roseville, MN
• WRC– Independent non-profit located in St Paul, MN
–One of the largest wildlife rehabilitation centers in the country
–Admit ~12,000 animals/year
–Over 185 species
–Complete veterinary hospital
–9 full-time staff members, 9 part-time/seasonal
–>600 volunteers
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Weaning Eastern Cottontail Diarrhea/bloat
• What do you know? What have you heard?
• Diagnosis or symptom?
Eastern Cottontail Gut (GI) Physiology
starting with adults
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Eastern Cottontail Gut (GI) Physiology
Oral cavity• Long hard palate and ventrally oriented trachea
– Make intubation difficult
– Less risky to gavage feed (neonates)
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Esophageal (cardiac) sphincter• Super strong doesn’t allow regurgitation
(from stomach) or vomiting
– Do not fast for surgery
– Products that cause eructation likely don’t work (iesimethicone/baby gas drops)
Stomach and small intestines• Easily digestible nutrients are absorbed
– Sugars
– Non-fiber
– Stomach: pH 1-2 to ‘sterilize’ ingesta before it goes into small intestine (helps prevent gastroenteritis)
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Ileocolic Valve• Sends indigestible fiber into
colon for excretion (normal fecal pellets)
• Sends fermentable fiber into cecum (cecotrophs)
Cecum• Bacterial fermentation and other
normal flora releases VFAs and makes proteins, vitamins
• These are excreted as cecotrophs
• = super food!
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Colon
• ...
Feces and cecotrophs• Feces are excreted and left
• Cecotrophs – Encapsulated in gel that
protects from acid of stomach
– are eaten directly from the anus
– small intestines absorbs the VFAs/vitamins/proteins
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LIVER
URINARY BLADDER
STOMACH
CECUM
Suckling GI anatomy/physiology
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Oral cavity (same)• Long hard palate and ventrally oriented trachea
– Less risky to gavage feed (neonates)
Esophageal (cardiac) sphincter (same)
• Super strong doesn’t allow regurgitation (from stomach) or vomiting
– Do not fast for surgery
– Products that cause eructation likely don’t work (iesimethicone/baby gas drops)
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Ruptured esophagus
• Prevent: hydrate before tubing
Ruptured esophagus
• Prevent: hydrate before tubing
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Stomach and small intestines• Easily digestible nutrients are absorbed
– MILK!
– Stomach: pH 5-6.5 allows bacteria to survive stomach so can colonize cecum (GI tract sterile when born)
• How can this cause a problem?
Stomach and small intestines• Rabbit stomach/small intestines are sterile for
entire suckling period
– other mammals’ guts populate w/ bacteria w/o hours of birth
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Stomach and small intestines• Rabbit stomach/small intestines are sterile for entire
suckling period – other mammals’ guts populate w/ bacteria w/o hours of
birth
• Rabbit doe milk has caprylic acid and capric acid which go though an enzymatic reaction in the stomach into “milk/stomach oil” which is antimicrobial
Rabbit milk oilrabbit milk
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Eastern Cottontail Milk
• Wet protein:fat of 34.6 : 50.9
– FV 32/40 is 32 : 40…..
– that’s a whole other lecture…
– SO MANY “recipes” so likely MANY MANY factors involved
Ileocolic Valve (same)• Sends indigestible fiber into colon
for excretion (normal fecal pellets)
• Sends fermentable fiber into cecum (cecotrophs) doesn’t start to happen until they eat fiber
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Cecum• While on milk, cecum is
small/inactive and sterile
STOMACH
CECUM
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When do they wean?Weight (grams) 1x per day 2x per day
45 4.5 ml
50 5.0 ml
55 5.5 ml
60 6.0 ml
65 6.5 ml
70 7.0 ml
80 8.0 ml
90 Self-feeding
When do they wean?
• 160g, Only milk (and a little hair) in stomach, cecum small and empty
• Base feedings on maturity, not weight alone
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Adult vs Suckling Rabbit GI Physiology
• “Normal Flora”
– Adult:
• Many different bacteria and protozoa
• No e.coli, no lactobaccillus
– Suckling:
• Sterile gut
• “stomach oil”
• Eat mom’s cecotrophs to gain “normal flora”
Another Important Fatty Acid
• Lower intestinal normal flora clostridia in adults produces butyric acid
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So…
• You admit an eye-closed infant…– Likely what “flora” is in the cecum?
• Likely sterile
– How clean are your practices?• Not very…
– What happens if you introduce pathogenic bacteria…
• VERY!– Great! But what happens when the rabbit starts to eat solid foods….where
are they digested? How are they digested? Will your rabbit be able to digest them? Then what happens…
• But I use probiotics!– What’s in them? Lactobacillus? Do rabbits have lactobacillus in their guts?
No! and lactobacillus sp are host species specific
– Is the probiotic doing anything?
Weaning Diarrhea/bloat
• IS A SYMPTOM, NOT A DIAGNOSIS
• MANY causes—no one treatment
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Be careful what you call bloat• Are they really bloated?
• Where is the bloat?
– Stomach?
– Cecum?
– Bladder?
Be careful what you call bloat
• Are they really bloated?
• Where is the bloat?
– Stomach?
– Cecum?
– Bladder?
radiographs
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12-7628
• Found on sidewalk, died before exam, 125g
• No evidence of diarrhea or other GI problems
12-7628
Stomach: milk AND
grass
Cecum: small
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12-7623• Finders ‘disturbed’ nest during yard work 4 days
ago
• Have been feeding kitten formula and vegetables
• Very thin, 104g, euthanized for fractured tibia
12-7623
Cecum: small
Stomach: empty
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12-7302
• Found DIC 7 d after admit, diarrhea on rear
• Admit: 66g, eyes-closed
12-7302
Cecum: enlarged, full of gas,
foul smelling
abnormal appearing
liquid
Stomach: full of gas,
foul smelling
abnormal appearing
liquid
Immediately post-mortem, microbes proliferate=excess gas/smell accumulate the longer the carcass sits; difficult to tell which signs are PM and which were present prior to death.
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12-7219
• DIC 9 days after admit, no diarrhea
• Admit: 58 g, eyes-closed, multiple lacerations to body
Cecum: enlarged, full of gas,
foul smelling
abnormal appearing
liquid
Stomach: small
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Weaning Diarrhea/Bloat
• Differentials:– GI infection
• Gastritis, enteritis, typhlitis
• Due to??– Infectious: Wrong bacteria (ie e coli), wrong protozoa, wrong
fungi, viral?
– Sudden diet change
– Urine retention
– LESS LIKELY: GI obstruction, hypomotility, etc
– WEANING diarrhea—why?• Started eating greens but….
PRIMARY NUTRITIONAL
SECONDARY EVERYTHING ELSE
Treatments
• *sigh*
• Depends on the diagnosis…which you likely will never have
• (what’s better than treatment?)
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Mylicon (simethicone)
• Helps animal expel gas in stomach via burping
• Rabbits can’t burp
XProphylactic antibiotics
• Can cause more harm than good
– Wiping out already established normal flora
– Causing resistant bacteria
• =Irresponsible antibiotic use
XFun Fact:
Baytril is illegal in hunted wildlife species, which
includes cottontails most places. So just don’t use it in wild
rabbits. Ever.
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Antibiotics for treating diarrhea
• Only work if you have a bacterial overgrowth
– If diarrhea is caused by something else (protozoal overgrowth, fungal overgrowth, etc) then an antibiotic can make it worse by killing the “good” bacteria
• Only work if the overgrown bacteria is susceptible to the antibiotic you are choosing
• Likely will kill other “good” bacteria in the GI tract
Antibiotics for treating diarrhea
• Cats/dogs:– Don’t have a large, fermenting
cecum
– Have a simple GI tract
– Diarrhea is often treated with antibiotics b/c they often have a bacterial enteritis
• RABBITS AREN’T DOGS/CATS– Metronidazole is also illegal in
hunted species…
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Pro-motility agents/antacids
• Reglan (metoclopramide), cisapride, ranitidine, famotidine
• Usually doesn’t work b/c motility is not the problem (in wild rabbits)
• If GI gas/bloat may help to raise stomach pH (ranitidine, famotidine) to prevent ulcers. …. Maybe….
Pro-motility agents/antacids
• Domestic rabbits often get gastric bloat early in GI disease
• Wild weaning cottontails almost never get gastric bloat they almost always have cecalbloat
• WILD RABBITS AREN’T DOMESTIC RABBITS
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Probiotics
• Lactobacillus usually absent in rabbit gut
– Lactobacillus in general is host species specific (see next slide)
Probiotics
• New studies in birds show that specific SPECIES of lactobacillus adhere to specific SPECIES of birds—no one lactobacillus works for all avian species!
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Probiotics
• Bacteria found in rabbit cecum:– Bacteroides, bifidobacterium ,
endophorus, clostridium, streptococcus, acuformis, Bacillus and Enterococcus
• Non-path protozoa found in rabbits GI– Entamoeba cuniculi, giardia dudenalis,
eutrichomastix, enteromonas, retortamonas
• http://www.vettimes.co.uk/article/beneficial-bacteria-in-pet-rabbits/#t1
Characteristics of probiotics (Weese, 2001; Kaur et al, 2002; Myers, 2007; Del Piano et al, 2011)
Products contains notes
Benebac Lactobacillus casei, Lactobacillus fermentum, Lactobacillus acidophilus, Lactobacillus plantarum, Enterococcus faecium, Bifidobacterium bifidum, Pediococcus acidilactici
Lactobacillus? Pfft. See previous slides
Rabbit papers listed other species of Bifidobacterium, not bifidum
Yogurt (activia) Bifidobacterium lactis DN-173 010 Rabbit papers listed other species of Bifidobacterium, not lactis
Saccharomyces cerevisiae (brewer’s yeast)
Shown to improve health in meat rabbits(improve growth performance, increase bodyweight, enhance haematopoiesis, reduce serum cholesterol , but doesn’t help with cecaldigestion(all just benefits of vitamin Bs?)
. Enteroccus faecium and E faecalis Able to survive the acidic gastric pH, colonize the mucosal surfaces and prevent the attachment of pathogens
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Probiotics
• Considering
• What would be the PERFECT rabbit probiotic?!
Distilled water?
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WRCMN and cecotrophs
WRC is a HIGH volume center
• This year we admitted ~2500 baby cottontails and attempted treatment/raised ~1500
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Cecotroph Protocol
1. Collect cecotrophs from domestic rabbit adults.
2. Mix them well with warm water and filter into liquid.
Cecotroph Protocol
1. Collect cecotrophs from domestic rabbit adults.
2. Mix them well with warm water and filter into liquid.
3. Feed 0.1 ml orally at each tube feeding
4. Cecotroph liquid is stored in refrigerator for 5-7d and the extra is kept in freezer.
Why shouldn’t this work?
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But where?
• Could e-collar your rabbit…
• Or….
• HoppyHour!!
WRC Pilot Study-Summer 2014• Hypothesis: cecotrophs can be used to treat
diarrhea.
• Methods: when cecotrophs were available, diarrhea rabbits were started on 0.05-0.1 ml at each formula feeding.
• 2014 was a horrible diarrhea/bloat year for us
year % ALL tx rel2013 40.72014 26.2
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Necropsy
• 13 diarrhea cases were sent to UMN VDL in 2014
– Rotavirus (5, 2 suspected)
– Beta-hemolytic E. coli (4)
– Uncertain (2)
– Non-hemolytic E. coli (4, significance is uncertain)
– Clostridium difficile toxin A/B (1)
– Coccidiosis (1)
A B
Time frame 4-8/2014 2013
No diarrhea hx
Received cecotroph protocol after diarrhea
31 0
Received cecotroph protocol before diarrhea had occurred
Diarrhea hx /NO cecotroph 0 111
Released cases 4 16
Release proportion 12.9% 14.4%
A = release rate of 2014 nursery rabbits on cecotroph treatment
B = release rate of 2013 nursery rabbits having diarrhea hx
Q: Do cecotrophs have treatment effect on rabbit post-weaning diarrhea?
2 sample z test, two-taileddesired significance level=0.05
p value is 0.8318 not significantCecotrophs after diarrhea had occurred group has no lower release rate than diarrhea rabbits in 2013.
A: NO.
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C D
Time frame 4-8/2014 9/2014
No diarrhea hx 430 29
Received cecotrophprotocol after diarrhea
31 0
Received cecotrophprotocol before diarrhea had occurred
0 3
Diarrhea hx 195 0
Released cases 186 18
Release proportion 28.4% 56.3%
Q: Do cecotrophs have preventive effect on rabbit post-weaning diarrhea?
2 sample z test, two-taileddesired significance level=0.05
p value is 0.0007 significantrelease rates between the two groups are different
A: YES.
Diarrhea proportion=
31%
Diarrhea proportion=
9%
P=0.008
Correlation does not equal causation
why else might have better success with
the last batch of bunnies?
Summer 2015
• Hypothesis: giving cecotroph slurry to every formula rabbit will decrease the diarrhea proportion
• Methods: ALL formula rabbits get 0.1 ml of cecotroph slurry at each formula feeding
year % diarr of tx%ALL tx
rel % diarr rel2013 16.2 40.7 13.62014 30.3 26.2 9.52015 16 40.9 20.1
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Summer 2015
• Then talked to interns and realized Cecotrophs weren’t always given….sooo…..
• Trash data…
• 2016 we made interns RECORD whether or not Cecotrophs were given
• Definitions– Study Group = bunnies
on formula (min 5 days)
– C = Only missed cecotrophs max of 1 day
– NC = Only received cecotrophs max of 1 day
– Juv = eyes open at time of admittance
– Inf = eyes closed at time of admittance
• Subject Pools– Entire Pool N =97
– Infants (Inf) N =26
– Juveniles (Juv) N =71
– Ceco (C) N =42
– No Ceco (NC) N =55
Summer 2016
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Diarrhea + Diarrhea - Group Total
Infants 19 7 26
Juveniles 31 40 71
Outcome Total 50 47 97
Findings - Diarrhea
Diarrhea Proportion Inf = 0.731 = 73.1%Diarrhea Proportion Juv = 0.437 = 43.7%
Statistically Significant? – At significance level (α) 0.05 YES with p <0.05 Z Score = 2.5677 | p-value = 0.01016Chi^2 Stat = 6.5928 | p-value = 0.010239
(TOTAL)
Diarrhea + Diarrhea - Group Total
Cecotrophs 16 12 28
No Cecotrophs 15 28 43
Outcome Total 31 40 71
Findings - Juveniles
Diarrhea Proportion C = 0.5714 = 57.14%Diarrhea Proportion NC = 0.349 = 34.9%
Statistically Significant? – NO with p <0.05Z Score = 1.8482 | p-value = 0.06432Chi^2 Stat = 3.4157 | p-value = 0.064579
(TOTAL)
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Diarrhea + Diarrhea - Group Total
Cecotrophs 8 6 14
No Cecotrophs 11 1 12
Outcome Total 19 7 26
Findings - Infants
Diarrhea Proportion C = 0.5714 = 57.14%Diarrhea Proportion NC = 0.9166 = 91.66%
Statistically Significant? – YES with p <0.05Z Score = -1.9785 | p-value = 0.0477Chi^2 Stat = 3.9144 | p-value = 0.047873
(TOTAL)
Release + Release - Group Total
Infants 5 19 26
Juveniles 24 47 71
Outcome Total 29 66 97
Findings - Release
Release Proportion Inf = 0.1923 = 19.23%Release Proportion Juv = 0.3380 = 33.80%
Statistically Significant? – NO with p <0.05 Z Score = -1.3886 | p-value = 0.16452Chi^2 Stat = 1.4226 | p-value = 0.232968
(TOTAL)
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Release + Release - Group Total
Cecotrophs 4 10 14
No Cecotrophs 1 11 12
Outcome Total 5 21 26
Findings - Infants
Release Proportion C = 0.286 = 28.6%Release Proportion NC = 0.083 = 8.3%
Statistically Significant? – NO with p <0.05Z Score = 1.3053 | p-value = 0.1902Chi^2 Stat = 3.9144 | p-value = 0.47873
(TOTAL)
Release + Release - Group Total
Cecotrophs 5 23 28
No Cecotrophs 19 24 43
Outcome Total 24 47 71
Findings - Juveniles
Release Proportion C = 0.179 = 17.9%Release Proportion NC = 0.442 = 44.2%
Statistically Significant? – YES with p <0.05Z Score = -2.292 | p-value = 0.02202Chi^2 Stat = 5.2534 | p-value = 0.021904
(TOTAL)
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• YES– Diarrhea in infants on cecotrophs & not on
cecotrophs?*– Release in juveniles on cecotrophs & not on
cecotrophs?*
• NO– Diarrhea in juveniles on cecotrophs & not on
cecotrophs?*– Release in infants on cecotrophs & not on
cecotrophs?*
“Significant” Findings?
What does this all mean?
• Bias selection of study group• Many uncontrolled variables
– Would euthanized animals have DIC or gone on to be released?
– Animals may have died of other causes• Diarrhea ≠ cecal dysbiosis
– Many different people involved in administration of cecotrophs
– Availability of cecotrophs likely not representative of bunnies throughout season• I.e. Available consistently during first wave of litters versus
last wave
Considerations with a Retrospective Study
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• Estimates Only – correlation ≠ causation
• Future Applications
– Repeat study in controlled setting
– Focus on cecotroph protocol in infants over juveniles?
– Increase daily cecotroph feeding?
Summary/Moving Forward
WRC’s NEW Approach to diarrhea in the weaning eastern cottontail
• Supportive care a must (don’t skimp on the fluids) even for healthy patients
• Everyone* gets prophylactic cecotroph slurry with every feeding
• ALL diarrhea rabbits are seen by a vet
• Assess patient attitude– BARF? Start pepto (1ml/kg PO BID x3d) +/- meloxicam,
recheck daily
– NOT BARF at any time or diarrhea worsens? Euthanize
• We no longer use any other treatment
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Future?
• Ensure every rabbit does indeed get Cecotrophs this summer by reporting it on feeding sheet
Questions? Thoughts?
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BID Feedings
• Eyes closed. Velveteen fur, Can’t support own weight
• Eyes just opened, still immature, not supporting own weight. Unsteady / unbalanced on feet.
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SID feedings
• Eyes open, Fur is not so sleek. Starting to become feistier. Ears not fully upright.
Self-feeding
• Eyes open, ears upright, Feisty, stands in an upright position.
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Rabbit milk oil
rabbit milk