Disease and Diagnostic Update

4/1/2016
Disease and Diagnostic Update
Darin Madson
[email protected]
Distribution of ISU VDL’s 78,341 Cases Accessions in FY2015
1
4/1/2016
Swine Respiratory Pathogens
PERCENT OF RESPIRATORY ACCESSIONS
50%
40%
30%
38%
26%
20%
10%
8%
7%
7%
3%
0%
3%
2%
2%
2%
1%
1%
1%
0.16% 0.12% 0.07% 0.01%
2
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Swine Influenza A Trends are Steady
14%
???
H1N1pdm09
PCV2b
PERCENT OF IAV‐S DIAGNOSIS
12%
10%
8%
6%
4%
2%
0%
2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014
IAV‐S Diagnosis
No known H5 found in swine to date; Iowa
Influenza Subtype Detections 2014
2013
2012
2011
2010
Percent of total IAV subtypes
50%
40%
30%
20%
2010
2011
10%
2012
0%
2013
Mixed
H3N1
H3N2
Year
2014
H1N2
H1N1
3
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4
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In the news……..
Infectious causes of diarrhea by age
Frequency of Etiological Diagnosis in Enteritis Cases
0.45
0.4
0.35
0.3
1 Week
2 Weeks
3 Weeks
0.25
0.2
0.15
0.1
0.05
0
ROTA
E. coli
Salm
C. diff
C. perf A C. perf C
Cocc
TGE
5
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Age distribution of rotavirus shedding
Group A only
Group B only
6%
≤ 7
33%
51%
8 ‐ 20
10%
≤ 7
28%
30%
7%
21 ‐ 42
35%
> 42
8 ‐ 20
21 ‐ 42
> 42
Group C only
10%
29%
56%
5%
≤ 7
8 ‐ 20
21 ‐ 42
> 42
KJ Yoon
Confidential
Agents of pig diarrhea: > 6 weeks of age (ISU‐VDL)
25%
20%
15%
10%
5%
0%
6
4/1/2016
PCVAD Trends Increasing?
PCVAD Cases by year
1200
1000
800
600
Total
400
200
0
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
PCV2 mutations/genotypes
•Mutation rate
• 1.2 x 10‐3 substitutions/site/year
• Highest rate reported for DNA viruses
•Recent report of a mutant PCV2 • In a herd with reported vaccine failure
• Identified PCV2 One extra amino acid in the OFR 2
• ORF 2 similar to PCV2b
• ORF 1 similar to PCV2a
• Combined sequence similar to a China PCV2d with proposed increased virulence 7
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Mulberry Heart Disease (MHD)
• 1st described in the late 1960s
• Vitamin E and/or selenium deficiency (1970s)
• Has been experimentally replicated with diets deficient in both vitamin E and selenium
• Multiple names
• White muscle disease (generally reserved for ruminants)
• Microangiopathy (coined first, prior to MHD)
ISU-VDL cases by year
ISU-VDL cases by month
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MHD: Causes????
• Vitamin E and/or Selenium deficiency
• Vitamin E and Selenium responsive
• Most believe that Vitamin E deficiency is the main component. • Infectious disease?
• Reports of Streptococcus suis and possibly Haemophilus parasuis
infection as a cofactor Possible risks factors for MHD
• Stocking density  increased stress
• Vitamin A deficiency
• High moisture corn
• Fungal growth decreases Vitamin E
• High fat diet – polysaturated fats
• Selenium deficient soil  decreased levels in corn and soybeans
• Antibiotics
• Sulfa containing drugs  Chelated by antioxidants
• Water • Metal levels
• Iron Injections
9
4/1/2016
Are lameness issues increasing?
• Importance of lameness
• Welfare issues
• Increased mortality
• Decreased growth efficiency • Concerns as likely enhanced by:
• Increased market weights
• Improved growth rates
• Variation in feed ingredients
Osteochondrosis
• Focal disturbance of bone formation
• Vascular compromise causes the focal disturbance
• Vascular issues are associated with multiple etiologies
• Trauma, sepsis
• Confounding issues
• Weight, conformation, copper status All pigs have some degree osteochondrosis
10
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Ytrehus et al. 2007
Metabolic bone disease
• Name given to nutritional bone disease associated with one or multiple of the following
• Calcium
• Phosphorous
• Vitamin D
Deficiency or ratio problem
• Rickets is the name applied to growing pigs
• Dog‐sitting, sudden death or muscle twitching are potential clinical signs
• Diagnosis
• Gross  soft ribs (bend before breaking), broken bones, enlarged ribs
• Microscopic  thickened growth plate
• Analyte testing  serum for calcium, phosphorous and vitamin D
11
4/1/2016
Mycoplasma spp. arthritis
• Mycoplasma hyosynoviae
• Typically older pigs
• Arthritis only • Red‐tinged joint fluid
• Mycoplasma hyorhinis
• Younger pig
• Polyserositis • Fibrinous arthritis
12
4/1/2016
Mycoplasma spp. arthritis Mycoplasma hyorhinis Mycoplasma hyosynoviae Common swine etiologies; infectious
Mycoplasma spp. arthritis
• Mycoplasma hyosynoviae
• Common late finishing or gilt lameness issue
• Swollen joints  not typical
• Lesions often seen in the stifle (knee)
MHS joint fluid
• Mycoplasma hyorhinis
•
•
•
•
Early finishing lameness
Swollen joints  yes
Lesions in stifle or hock
Need to differentiate from other bacteria
MHR joint fluid
13
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Hemorrhagic Bowel Syndrome
• Originally: Syndrome of sudden deaths in whey‐fed pigs; 1959
• Current:
• Sudden death of previously healthy pigs
• Sporadic, from 0‐4% mortality (20‐33% of total mortality)
• More common in summer in pigs 18‐26 weeks
• Many “HBS” deaths are really partial volvulus / intestinal torsion
• No gender differences
Hemorrhagic Bowel Syndrome
• Risk factors: 1. Anything that contributes to inconsistent feed intakes
2. Large meals
3. Fighting, playing, mounting behavior • Possible pathogenesis: • Disruption of feed intake  microflora “bloom” toxemia, allergy?
• Diagnosis by exclusion  becomes a “default diagnosis”
• Rule out volvulus, torsion, gastric ulcer, etc.
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Hemorrhagic Bowel Syndrome
Complete volvulus: segmental necrosis
15
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Gastric Ulceration
• Location = pars esophagea
• Increased frequency with modern production • intensive housing
• No sex predication
• Equal amongst barrows and gilts
• Increased growth promotes (high health)
• Prevalence at slaughter 32‐64%
• Development and resolution
• 12‐24 hrs
• Can heal quickly too
• Chronic 5‐51 days
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Gastric Ulceration
• Risk factors
“Anything that causes an empty stomach”
•
•
•
•
•
Out of feed event
Erratic feeding practices
Stress  social or environmental Disease  typically respiratory disease
Feed particle size
•
•
•
•
High carbohydrate diets
Mycotoxins  feed refusal
Copper toxicity Vitamin A toxicity
Gastric Ulcer
Must look at pars esophagea
May be intermittent bleeding anemic but no blood clot in stomach
Usually dark feces (melena)
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Questions???
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