Deciphering Diarrhea - What's Important - Dr. Darin Madson, Iowa State University, from the 2012 Allen D. Leman Swine Conference, September 15-18, St. Paul, Minnesota, USA. More presentations at http://www.swinecast.com/2012-leman-swine-conference-material

1. Deciphering Diarrhea
What’s Important
Darin Madson
Iowa State University
madson@iastate.edu

2. Goal of the Presentation
To firm-up diagnostic issues
as it relates to swine
diarrhea

3. Understanding the GI Tract
• Small intestinal disease
– Normal frequency
– High volume (watery)
– If blood: digested (brown) – dark green to brown watery stool
• Large intestinal disease
– High frequency
– Low volume
– Mucous
– If blood: fresh (red) Dysentery
– Anorexia

4. Understanding the GI Tract
• Viral Diseases
– Virus is present a short time
– Select acute pigs for testing (1st 24 hours of diarrhea)
• Bacterial Diseases
– Therapeutic antibiotics interferes with testing
– Select untreated pigs for testing
• Intestinal mucosa autolyzes rapidly
– Select only euthanized pigs for testing
– Fix intestinal segments within 15 minutes of death
• Lesions are often segmental in intestine
– View many segments at each “level”
– Collect multiple segments of each “level”

5. Understanding the GI Tract
• Normal flora
– More commonly referred to as the microbiome
– Extensive population of bacteria
• ~1014 bacterial
– Numerous benefits to the pig
• Break-down of feed stuffs (metabolic issues)
• Water transport
• Aids in immunity
We are only starting to understand the diverse
interaction of the swine microbiome

6. Diagnostic Interpretation
• Understand testing limitations
– A positive result does not always indicate cause
– A negative result does not always exclude a cause
• Beware of your own and other’s bias
– Experience is invaluable, but can lead you astray
– Be objective during investigations
• Interpretation = combining the history with the
clinical information and the diagnostic results to
make a final judgment; case diagnosis

7. NEONATAL DIARRHEA

8. Neonatal Diarrhea Concepts
• New-born pigs = sterile gastrointestinal tract
• At birth
– Race for bacterial colonization
– Overgrowth is common
– Environment and immunity play a role
Neonatal diarrhea is:
Often infectious and can be associated with management issues

9. Management Influences
Transmission Dam immunity
• Gestation • Gestation
– Stalls vs. pens vs. open lots – Stalls vs. pens vs. open lots
• Parity distribution • Parity distribution
• Gilt acclimation • Vaccination – feed back
• Housing design • Sow milking
• Sanitation – Feeding practices
• Flooring material – Sow comfort
• Room management • Pig suckling
– pig flow

10. TGEV
Rotavirus (A , B, C)
E coli
Coccidiosis
C perf. type C
C perf. type A
C difficile
1 2 3 4
Weeks of Age

11. Neonatal Diarrhea – Game Time

12. POST-WEANING AND FINISHING
DIARRHEA

13. Immediate Post-Weaning Diarrhea
Group A only
6%
• Rotaviruses & hemolytic E. 33% ≤7
8 - 20
coli 51%
10% 21 - 42
> 42
– ~ 5 days post-weaning.
Group B only
• E. coli disease
30% 28% ≤7
– Mostly hemolytic strains 7%
8 - 20
21 - 42
35%
> 42
Pathogenic E. coli identified
ETEC Group C only
F5(K99), F6(987P),
Criterion F4(K88) F18
F41
10% ≤7
Hemolytic 29%
All (not discriminatory) None 8 - 20
colonies 56%
21 - 42
Modified from 10th ed: disease of swine
> 42
5%
KJ Yoon – rotavirus information

14. Salmonella sp.
• S. typhimurium
• Diarrhea
• Small and large intestine affected
• Serogroup B
• S. choleraesuis
• Septicemia then diarrhea
• Serogroup C1
• Other isolates
• Salmonella spp. isolated from pigs may not be contributing
to clinical illness
• Carrier pigs
• Isolation
• Direct culture vs. enrichment

15. Porcine Proliferative Enteropathy
• Proliferative hemorrhagic enteropathy
• PHE is “acute hemorrhagic” form
• Porcine intestinal adenomatosis
• PIA is “proliferative” form
• Necrotic enteritis
• NPE is “chronic” form
• ALL the same disease, caused by:
• Lawsonia intracellularis

16. Catarrhal Colitis
• Caused by Brachyspira spp. including:
– B. pilosicoli, B. murdochii, possibly others
– Weakly hemolytic isolates
• Mild diarrhea
• Lesions limited to colon
• Diagnosis
– culture followed by PCR

17. Swine Dysentery
• Associated with strongly beta-hemolytic
Brachyspira spp.
– B. hyodysenteriae
– B. hampsonii
• Lesions limited to large intestine
– mucohemorrhagic to necrohemorrhagic
typhlocolitis

18. Non-infectious diarrhea
Non-specific colitis
• Inflammation without pathogen detection
– “Dysbacterosis”
– Increasing prevalence in diagnostic submission
– Disruption in the colonic microbiome
• Diet change Can led to infectious diarrhea
• Diets ingredient change
• Water quality
• Mineral levels or mycotoxins
– Treatment, duration, and immunity related to an
infectious pathogen
Mucus – feature or colitis and is not always associated with Brachyspira sp. infection

19. Non-infectious diarrhea
Osmotic diarrhea
• Water quality issues
– Sulfates and total dissolved solids (TDS)
– Prevent colonic water absorption

20. Grow/Finish Diarrhea – Game Time

21. Take Home Points
• Neonatal diarrhea
– Mostly infectious……..but
– Related to environment, immunity, and etc.
– Race for bacterial colonization
• Post-weaning/grow-finish
– Mixture of infectious and non-infectious
– Diets plays a large role
– Often over-interpretation of infectious pathogen
detection

22. Keys to Diagnostic Success
1. Sample quality and selection
• Non-treated & acutely affected
2. Diarrheal causes are not always infectious
• Feeding or nutritional microbiome changes
3. Pathogen detection ≠ cause
• Do not over-interpret results; context
4. Be observant (unbiased)
• Large bowel vs. small bowel disease
• Diet changes

23. Questions?
Thanks for listening