Title: Trouble Shooting Mastitis Problems: Using laboratory culture diagnosis to make mastitis treatment de
1Trouble Shooting Mastitis ProblemsUsing
laboratory culture diagnosis to make mastitis
treatment decisions
- Philip Sears, DVM, PhD
- Department of Large Animal Clinical Science
- College of Veterinary Medicine - Michigan State
University - East Lansing, Michigan USA
2Herd Investigation Disease Control
Step 1 Define Problem Use Dairy Analysis
Workbook - page 24) List possible
problems Review records (health, DHIA)
Review farm monitors to identify patterns Step
2 Use Diagnostic Testing to Determine Problem
Diagnostic Laboratory results
Veterinarian Other laboratories Step 3
Generate and Select Solutions Step 4 Develop a
Farm Plan Protocols Set goals
Create Standard Operating Procedures (SOPs)
Monitor records
3Clinical Mastitis Definition
- Score 1 Mild (signs milk)
- abnormal milk
- Score 2 Moderate (signs milk gland)
- abnormal milk
- swelling, pain
- Score 3 Severe (signs milk, gland cow)
- abnormal milk
- swelling, pain
- systemic fever, dehydration shock
Sears, 2001
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5Clinical Predictive Schemefor Gram-negative
Mastitis
- White, et al Jones Ward Morin, et al
- watery milk watery milk watery milk
- swollen gland summer summer
- fever fever ? milk protein
- weakness gt10 dim ? rumen sounds
- clear/white milk old cow
- no abscesses
- previous mastitis
watery milk more common in Strep mastitis than
coliform mastitis - Obritzhauser et al, 1995
6Clinical Predictive Schemefor Gram-negative
Mastitis
- 3 experienced practitioners correctly predicted
21/36 (58) culture results - 4 less experienced practitioners correctly
predicted 39/82 (48) culture results - For coliform mastitis
- Sens .64, Spec .64
- PPV .51, NPV .76 (prevalence 31)
White et al, 1986
7Milk Cultures
- Infection level in herd
- Type of infections
- Source of infections
- Control and Prevention
8Milk Cultures
- Clinical quarters or cows
- Herd analysis
- all cows
- HSCC cows
- monitoring herd
- bulk tank milk
9Milk Culture
10Milk Culturessample consideration
- Cow samples
- Composite cow samples for herd survey
- quarter samples - clinical cases, high SCC
11Milk Sampling
12Mastitis Problem Solving
Step 1 Identify possible mastitis problems.
(review records)
Subclinical mastitis
Clinical mastitis
Bulk tank SCC gt250,000 cell/ml
DHIA - SCC gt15 with LSgt4.5
New clinical cases gt2 per month
Severe clinical cases gt1 per year
Step 2 Use diagnostic test to determine
causative organism.
Bacteriological Cultures
Environmental organisms (usually clinical)
Contagious organisms (usually subclinical)
Coliforms
Strep sp
Staph sp
Staph aureus
Strep ag
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14Culture Results
- Culture results from clinical mastitis and high
SCC - Combine with SCC, milk prod, DIM and preg
diagnosis - Cow and herd recommendation decision
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16Mastitis Problem Solving
Step 1 Identify possible mastitis problems.
(review records)
Subclinical mastitis
Clinical mastitis
Bulk tank SCC gt250,000 cell/ml
DHIA - SCC gt15 with LSgt4.5
New clinical cases gt2 per month
Severe clinical cases gt1 per year
Step 2 Use diagnostic test to determine
causative organism.
Bacteriological Cultures
Environmental organisms (usually clinical)
Contagious organisms (usually subclinical)
Coliforms
Strep sp
Staph sp
Staph aureus
Strep ag
Step 3 Generate possible solutions.
Treatment Decision
Treatment Decision
Treat clinical cases Treatment Plan Treatment
Protocols
Culture high SCC Segregate Cull chronic
Culture herd Treat positive cows Reculture treat
/cull
Prevention
Prevention
Clean/dry bedding Clean udders Premilking udder
pre Proper milking Maintain milking
equip Nutrition Vit E Se
Premilking udder prep Proper milking Postmilking
teat dip Maintain milking equip Dry cow
therapy Culture purchased animals
17Clinical Mastitis Therapy Decisions
- Large dairy 3200 milking cows in Michigan
- Culture all clinical mastitis cases
- Treat mastitis based upon culture results
18- Standard Mastitis Protocol
- Abnormal milk
- Intramammary antibiotic for 3 days
- Continue treatment for 2 additional days
- Change antibiotics two days
- Remove from production untreatable
19METHODS
- Culturing Clinical Cases
- Culture every new clinical case as they enter
pen - With hold treatment 24 hrs for culture results
- Unless cow is systemic ill or fever
20METHODS
New Mastitis Protocol Culture
and record in Dairy Comp 305 Protocol base on
culture results Gram-negative NO
TREAT Gram-positive TREAT
21 New Mastitis Protocol Protocol
Gram-negative NO TREAT Monitor both the cow
and the quarter at each milking until milk is
normal Fever or Illness supportive therapy
Banamine Fluid therapy
22 New Mastitis
Protocol Protocol Gram-positive
TREAT Monitor at each milking until milk is
normal Intramammary antibiotic treatment If
milk does not return to normal cease milking
qrts If chronic repeater and clinical cease
milking qrts
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2520 Tx
80 NT
Hess 2003
2620 Tx
80 NT
Hess 2003
27Results
- New Treatment Protocol
- With the 24 hour with hold for culture ,
antibiotic treatment was reduced 80 - Gram-negative bacteria 30
- No growth (coliforms/strep sp) 50
28Results
- New Treatment Protocol
- With the 24 hour with hold for culture
- Gram-positive bacteria
- no change in days out of tank
- no change in number of treatments
- no change in quarters loss
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31CONCLUSION
E. coli and no growth did not benefit from
antibiotic treatment for salable milk and
clinical signs. Culture identified no growth and
Coliforms rapidly (24 hrs). Treatment delay
reduced antibiotic use by 80. Treatment delay
did not effect clinical outcome for Gram-positive
bacteria (Strep Staph, 20 of cases). Change
in treatment protocol did not jeopardize the
health or well-being of the animal.
Hess 2003
32Milk Cultures
1. Select cows for culture (herd, HSCC, etc) 2.
Collect an aseptic milk sample 3. Collect
composite or quarter milk sample 4. Refrigerate
(or ice) sample at collection
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34 watery milk more common in Strep mastitis than
coliform mastitis - Obritzhauser et al, 1995
35Culture milk on blood agar plates or selective
media.
36Blood agar Selective media MacConkey
agar Blood-esculin agar
37Major Mastitis Pathogens Isolation
Selective Media
Philip Sears, DVM, PhD Department of Large Animal
Clinical Science
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39Selective Media - Bi-plates
1
Large grey colonies
arrow shape
2
3
40Gram-negative rods KOH positive Large grey
colonies moists or mucoid
Coliforms
Klebsiella sp
E. coli
41Gram-negative rods KOH positive Large grey
colonies moists or mucoid
Coliforms
Klebsiella sp
E. coli
42Gram-negative rods KOH positive Large grey
colonies moists or mucoid
Coliforms
Klebsiella sp
E. coli
43Gram-positive cocci KOH negative Small
translucent colonies
Streptococci
Streptococcus agalactiae
Selective media Blood agar-esculin
Streptococcus spp) Str. uberis, enterococci,
beta-hemolytic colonies
esculin reaction
CAMP Test
44Gram-positive cocci KOH negative Small
translucent colonies
Streptococci
Streptococcus agalactiae
Selective media Blood agar-esculin
Streptococcus spp) Str. uberis, enterococci,
beta-hemolytic colonies
esculin reaction
CAMP Test
45Gram-positive cocci KOH negative Small
translucent colonies
Streptococci
Streptococcus agalactiae
Selective media Blood agar-esculin
Streptococcus spp) Str. uberis, enterococci,
beta-hemolytic colonies
esculin reaction
CAMP Test
46Gram-positive cocci KOH negative Small
translucent colonies
Streptococci
Streptococcus agalactiae
Selective media Blood agar-esculin
Streptococcus spp) Str. uberis, enterococci,
beta-hemolytic colonies
esculin reaction
CAMP Test
47Gram-positive cocci KOH negative Opaque
colonies white to yellow colonies
Staph aureus
Staph sp
Staphylococci
Staph sp
Staphylococcus aureus
Staph aureus
? ?
-
Staph sp
Coagulate plasma
Double zone hemolysis
Coagulase Test
(? - ?)
48Gram-positive cocci KOH negative Opaque
colonies white to yellow colonies
Staph aureus
Staph sp
Staphylococci
Staph sp
Staphylococcus aureus
Staph aureus
? ?
-
Staph sp
Coagulate plasma
Double zone hemolysis
Coagulase Test
(? - ?)
49Gram-positive cocci KOH negative Opaque
colonies white to yellow colonies
Staph aureus
Staph sp
Staphylococci
Staph sp
Staphylococcus aureus
Staph aureus
? ?
-
Staph sp
Coagulate plasma
Double zone hemolysis
Coagulase Test
(? - ?)
50Clinical Mastitis Pathogen Isolation
Sears, 2003
51Clinical Mastitis Pathogen Isolation
Selective media
Selective media
Sears, 2003
52Mastitis Problem Solving
Step 1 Identify possible mastitis problems.
(review records)
Subclinical mastitis
Clinical mastitis
Bulk tank SCC gt250,000 cell/ml
DHIA - SCC gt15 with LSgt4.5
New clinical cases gt2 per month
Severe clinical cases gt1 per year
Step 2 Use diagnostic test to determine
causative organism.
Bacteriological Cultures
Environmental organisms (usually clinical)
Contagious organisms (usually subclinical)
Coliforms
Strep sp
Staph sp
Staph aureus
Strep ag
Step 3 Generate possible solutions.
Treatment Decision
Treatment Decision
Treat clinical cases Treatment Plan Treatment
Protocols
Culture high SCC Segregate Cull chronic
Culture herd Treat positive cows Reculture treat
/cull
Mild mastitis - abnormal milk Intermediate/moderat
e - pain, swelling Severe mastitis - systemic
fever, dehydration shock
53Clinical Mastitis Treatment Protocol
Remove cow
Quarter loss to
production
Cull
Return to Herd
Milk
Hess 2003
54Treatment Decisions
In a recent article that used a clinical mastitis
model, antibiotic treatment is not profitable.
The cost of milk discard off-sets the gain in
production.
(Bennedsgaard, 2003) However, these models place
all pathogens together and do not separate out
staphylococcal and streptococcal mastitis that
can respond favorably to antibiotic therapy.
(Wilson, 1996)
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57Summary
- Culturing milk from subclinical infected cows
can aid in the development of mastitis treatment
protocols and mastitis prevention plans. - Culturing milk from clinical mastitis cases can
be useful in identifying cases responsive to
antibiotic therapy and reducing antibiotic
residues without jeopardizing animal health.
58Susceptibility Testing Methods
Incubate plate 18-24 hr, 35 C Measure and record
zone of inhibition around each disk
Innoculate MH plate
Place disks on agar plate
59Disk Diffusion Susceptibility Testing
60Antimicrobial susceptibilitytesting using
micro-broth dilutions
ug/ml 64 32 16 8 4 2
96 well microtiter plate
61Antimicrobial Gradient TestingE-test
Read plates after recommended Incubation
Read MIC where elipse intersects scale
62Focus on Gram Positives (MIC)
Susceptibility Testing
- 10 random samples that cultured coagulase
negative Staph spp. (CN Staph) and 10 random
samples that cultured environmental Strep spp.
were submitted to Dr. Bolins lab at the Animal
Health Diagnostic Lab at Michigan State
University - The MIC for each sample was determined
- Based upon the results, the MIC50, MIC75 and
MIC90 for each group of organisms were calculated
(antibiotic susceptibility levels for 50, 75
and 90 of each group)
63Results of Susceptibility TestingEnvironmental
Strep spp.
64Results of Susceptibility TestingEnvironmental
Staph spp.
65Decisions
- 90 of Environmental Strep spp. Were susceptible
to Ampicillin (Amoxicillin) and
Penicillin/Novobiocin and potentially Penicillin - 90 of Coagulase Negative Staph spp. Were
susceptibile to Cephalothin, Penicillin/Novobiocin
and potentially Pirlimycin, Ampicillin
(Amoxicillin) and Penicillin
66Current Clinical Mastitis Treatment Protocol
- Environment Strep
- 5-7 days of Amoximast therapy intramammary BID
- 5-7 days of Penicillin therapy systemically BID
- Coag-negative Staph
- 5-7 days of Cefa-Lak therapy intramammary BID
- 5-7 days of Penicillin therapy systemically BID
67Keep Health and Treatment Records
- Calendar or notebooks
- Daily Treatment Records (AABP records)
- Health Programs (Dairy Comp 305, Dairy CHAMP)
- DHIA - PC Dart ( health input summaries)
68Animal Treatment Plan AABP record sheet - 2A
- Disease diagnosis and treatment protocol
- Milk and meat withdrawal time
69Animal Treatment Plan AABP record sheet - 2A
70Packet Page 2
Daily Treatment Record (Barn Sheet) Fresh Cows
Record AABP record sheet
- Cow by calving and treatment activity
- Disease diagnosis and treatment
- Treatment record for each fresh cow
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72Health Monitor - Number of cases
Detecting the Demons in your Dairy Diagnostic,
Protocols, and Monitoring Tools for Your Dairy
Time period ___________
Number cows ____
Number cases
1 2 3 4 5 6 7 8 9 10 11 12 13
14 15 16 17 18 19 20
RP
DA
Off feed
Downer
CMT 1-3
Diarrhea
Lameness
Milk fever
BCS lt2.5
Metritis
Ketosis
Udder edema
Mastitis-New
Mastitis-Severe
73Health Monitor - Number of cases
Detecting the Demons in your Dairy Diagnostic,
Protocols, and Monitoring Tools for Your Dairy
Time period ___________
Aug - Oct, 1999
46
Number cows ____
(full)
43
33
22
Number cases
1 2 3 4 5 6 7 8 9 10 11 12 13
14 15 16 17 18 19 20
9
7
7
4
4
2
2
RP
DA
CMT 1-3
Downer
Off feed
Diarrhea
Lameness
Milk fever
BCS lt2.5
Metritis
Udder edema
Mastitis-severe
Ketosis
Mastitis-new
74BEST MANAGEMENT PRACTICES
MASTITIS DECISION TREE
Bulk Tank Somatic Cell Count (BTSCC)
DHI-SCC
Cow DHI-LS 4 or greater
CMT quarters
Positive quarters (CMT 1 or greater)D
Staph aureus (SA) Mycoplasma Coag neg Staph
Strep agalactiae (Sag)
Environmental Strep sp Coliforms
Depopulate (Sag)
Treat IMM
Depopulate IMI cows Dry off lt80 days Sell
chronic cows Kill bad quarter(s)
Identify source Housing Bedding Teat dip
pre post Pasture
Reculture
Treat IMM
Segregate at milking Test all fresh cows
heifers Positive SA to SA group
Reculture
Cull
Culture all fresh cow heifers
Mellenberger, 1996
75BEST MANAGEMENT PRACTICES for CONTAGIOUS MASTITIS
76BEST MANAGEMENT PRACTICES for CONTAGIOUS MASTITIS
(cont)
77BEST MANAGEMENT PRACTICES for ENVIRONMENTAL
MASTITIS
78BEST MANAGEMENT PRACTICES for ENVIRONMENTAL
MASTITIS (cont)
79BEST MANAGEMENT PRACTICES for ENVIRONMENTAL
MASTITIS (cont)
80Mastitis Problem Solving
Step 1 Identify possible mastitis problems.
(review records)
Subclinical mastitis
Clinical mastitis
Bulk tank SCC gt250,000 cell/ml
DHIA - SCC gt15 with LSgt4.5
New clinical cases gt2 per month
Severe clinical cases gt1 per year
Step 2 Use diagnostic test to determine
causative organism.
Bacteriological Cultures
Environmental organisms (usually clinical)
Contagious organisms (usually subclinical)
Coliforms
Strep sp
Staph sp
Staph aureus
Strep ag
Step 3 Generate possible solutions.
Treatment Decision
Treatment Decision
Treat clinical cases Treatment Plan Treatment
Protocols
Culture high SCC Segregate Cull chronic
Culture herd Treat positive cows Reculture treat
/cull
Prevention
Prevention
Step 4 Develop Farm Plan Protocols
- Set goals
- Create Standard Operating Procedures (SOPs)
- Monitor records