1. Sukolrat Boonyayatra DVM, MS Clinic for Ruminants
Bovine Mastitis
Sukolrat Boonyayatra
DVM, MS
Clinic for Ruminants

2. What’s mastitis ? Inflammation of one or more quarters of the udder
Mammae = breast
-itis = Latin suffix for
inflammation
Normal
Inflamed
Swelling
pain
warm
redness

3. Causes Intramammary Infection (IMI): Mechanical trauma Predisposes
Bacterial infection
Mycoplasmal infection
Mycotic (fungal) infection
Algal infection
Mechanical trauma Predisposes
Thermal trauma the gland to IMI
Chemical insult

4. Economic Losses
Mastitis accounted for 26% of the total cost of all dairy cattle diseases.
Losses from mastitis were twice as high as losses from infertility and reproductive diseases.
Sources of loss
Reduced milk production
Discarded milk
Early cow replacement costs
Reduced cow sale value
Drugs
Veterinary services
labor

5. Determinants of Mastitis

6. Timing of infection and stage of lactation
Active involution
High Pressure in the gland
Bacteria inside the gland
Teat dipping ceases.
Phagocytic efficiency
Increasing of immunoglobulins and lactoferrin cannot override the problems noted above.
Dry cow treatment can not reduce coliform IMI during active involution.
Reducing the period of active involution by infusing colchicine (disrupts milk secretion mechanisms) decreases IMI during the active involution phase.

7. Timing of infection and stage of lactation
Peripartum period
Fluid volume in the gland increases
Citrate concentration rises and lactoferrin is low
Phagocytic cells efficiency
High immunoglobulin concentrations in the gland at this time are not effective in preventing new IMI.
IgG1 is not normally an effective opsonin in the mammary gland.
Antibiotic concentration
Teat dipping

8. Timing of infection and stage of lactation
Early lactation
Metabolically stressed
Mastitis is sometimes associated with high concentrate feeding which accompanies early lactation.

9. Nutrition and Mastitis
Micronutrient
Observation Se
Decreased efficiency in neutrophil funtion
Improved bactericidal capabilities of neutrophils
Decreased severity and duration of mastitis
Vit E
Increased neutrophil bactericidal activity
Decreased incidence of clinical mastitis
In combination with Se, decreased prevalence of IMI at calving
Vit A
Decreased SCC
Moderated glucocorticoid levels
β-carotene
Increased bactericidal function of phagocytes
Increased mitogen-induced proliferation of lymphocytes Cu
Deficiency decreased neutrophil killing capability
Deficiency increased susceptibility to bactericidal infection Zn
Deficiency decreased leukocyte function
Deficiency increased susceptibility to bacterial infection

10. Inflammation of Mammary gland
1. Multiplication of bacteria in mammary gland
2. Vasodilation
3. Increased vascular permeability
4. Swelling
5. Diapedesis
6. Phagocytosis and destruction of bacteria
7. Tissue repair

11. Development of mastitis and the cow’s defense against the infection  

12. The major routes of bacterial transmission  

13. Mastitis Clinical Syndromes
Categorized based on Severity of Immune Response
Peracute Mastitis: sudden onset, severe inflammation of the udder, and serous milk-Systemic illness often precedes the symptoms manifested in the milk and mammary gland.
Acute Mastitis: sudden onset, moderate to severe inflammation of the udder, decreased production, and occurrence of serous milk/fibrin clots, Systemic signs are similar but less severe than for the peracute form.

14. Mastitis Clinical Syndromes
Subacute Mastitis: mild inflammation, no visible changes in udder, but there generally are small flakes or clots in the milk, and the milk may have an off-color. There are no systemic signs of illness.
Chronic Mastitis: Chronic mastitis may persist in a subclinical form for months or years with occasional clinical flare-ups. Treatment usually involves treating the clinical flare-ups, or culling the cow from the herd.

15. Mastitis Clinical Syndromes
Subclinical Mastitis: the most common form of mastitis, 15x40 X more common than clinical mastitis, no gross inflammation of the udder and no gross changes in the milk, decreased production and decreased milk quality
Elevated Somatic Cell Count

20. Abnormal Milk

21. Abnormal Udder

25. Somatic Cell Count
~98-99% White Blood Cell + 1-2% Epithelial cells from milk-secreting tissue
Cow’s natural defense mechanism
Normal or uninfected cow: 50, ,000 cells/ml
>200,000 cells/ml: the likelihood of infection increase
Prevalence of subclinical mastitis in Chiang Mai may be exceed 80%.
1 clinical mastitis : subclinical mastitis

26. Effects on Milk Quality
Subclinical mastitis results in INCREASES in undesirable milk components and DECREASES in the desirable components.
Pasteurized milk that is processed from raw milk with a somatic cell count below 250,000 has a significantly longer shelf-life than products made from milk with a somatic cell count above 500,000.

27. Lactose (good)
Total proteins (good)
Casein (good)
Immunoglobulins (bad)
Solids not fat (good)
Total solids (good)
Fat (good)
Lipase (bad)
Sodium (bad)
Chloride (bad)
Calcium (good)
Phosphorus (good)
Potassium (good)
Trace minerals (bad)
Cheese (good)
Heat stability (good)
Decreased 5 to 20%
Decreased slightly
Decreased 6-18%
Increased
Decreased up to 8%
Decreased 3 t0 12%
Decreased 5 to 12%
Increased rancidity
Decreased
Slight increase
Decreased curd strength, fat and yield
Reduced

28. What are the health concerns of mastitis ?
Animal health
Loss of functional quarter
Lowered milk production
Death of cow
Human health
Poor quality milk
antibiotic residues in milk

29. How severe can mastitis be ?
Subclinical Mastitis
~ % of all mastitis cases
Udder appears normal
Milk appears normal
Elevated SCC (score 3-5)
Lowered milk output
(~ 10%)
Longer duration
Clinical Mastitis
~ % of all mastitis cases
Inflamed udder
Clumps and clots in milk
Acute type
major type of clinical mastitis
bad milk
loss of appetite
depression
prompt attention needed
Chronic type
cow appears healthy

30. What causes mastitis ? Bacteria ( ~ 70%) Yeasts and molds ( ~ 2%)
Unknown ( ~ 28%)
physical
trauma
weather extremes

31. Where do these organisms come from ?
Infected udder
Environment
bedding
soil
water
manure
Replacement animals

32. How does mastitis develop ?
Cow
Predisposing conditions
Existing trauma (milking machine, heat or cold, injury)
Teat end injury
Lowered immunity (following calving, surgery)
Nutrition
Organisms
Environment

33. Process of infection Organisms invade the udder through teat canal
Migrate up the teat canal and colonize the
secretory cells
Colonized organisms produce toxic substances
harmful to the milk producing cells

34. The cow’s immune system send white blood cells (Somatic cells) to fight the organisms
recovery
clinical
subclinical

35. Organisms Contagious microorganisms Environmental microorganisms
Staphylococcus aureus
Streptococcus agalactiae
Mycoplasma bovis
Corynebacterium bovis
Environmental microorganisms
Environmental streptococci
Coliform
Opportunistic microorganisms
Staphylococcus spp. (CNS)
Others
Pseudomonas aeruginosa
Actinomyces pyogenes
Nocardia Species

36. Bacterial Infection: Streptococci
Environmental
S. uberis
S. dysgalactiae
S. equinus
More subclinical mastitis
Environment
Predominant early and late lactation
Contagious
S. agalactiae
Clinical mastitis
Resides in the milk and on the surface of the milk channel
Cannot invade the tissue
Accumulate Neutrophils
Ducts and acinar epithelium damage
Inter-alveolar tissue fibrosis loss of secretory function
Treated easily with penicillin

37. Bacterial Infection: Staphylococci
Staph aureus
Gangrenous mastitis: alpha toxin
Spread by milking equipment and milker’s hands
Fibrous tissue replacement low production
Poor response to ABO
Dry cow therapy
Persistent, difficult to eliminate
Other staph
Found normally on skin
Lowers milk yield
Elevated SCC
Easily responds to antibiotics
Relapse frequently seen

38. Fig. 1. Mammary parenchyma from which coagulase-negative Staphylococcus was isolated, showing the presence of mononuclear cells. HE   

39. Fig. 2. Mammary parenchyma from which coagulase-negative
Staphylococcus was isolated, showing the presence of
neutrophils within the alveolar lumen. HE   .

40. Fig. 3. Mammary parenchyma from which Prototheca sp
Fig. 3. Mammary parenchyma from which Prototheca sp. was isolated, showing the micro-organisms within the alveolar lumen. HE   .

41. The cocci in the lesions of the mammary glands
show a positive reaction
to antibody against
Staph.aureus (ABC X 200)

42. The bacteria were round or oval
in shape, showing a thick cell wall,
characteristic of gram-positive bacteria
(TEM. X 40,000)
b. Fibrous material (arrows) stained by
ruthenium-red, around the bacterial
cell wall, which forms a capsule
(TEM.X 250,000)

43. Severe necrosis of interlobular
and intralobular ducts The lesions affected
the intralobular duct,
intralobular duts and alveoli
(Azan x 30).

44. Bacterial clumps(arrows)
surrounded by alveolar epithelial
cells undergoing necrosis Thrombus(*)is seen in
the blood vessel(He x 100).

45. Bacterial Infection: Coliforms
Groups of organisms
E. coli, Klebsiella, Enterobacter
Environmental source (manure, bedding, barns, floors and cows)
Coliforms cause acute clinical mastitis
Multiply rapidly with low SCC
Endotoxin releasing
High temp, and inflamed quarter
Watery milk with clots and pus
Toxemia
The udder can be gradually return to normal without fibrosis

46. Bacterial Infection: Other organisms
Pseudomonas aeruginosa
Out breaks of clinical mastitis or subclinical mastitis
Similar pathogenesis to coliform mastitis
Severe endotoxaemia can occur.
Serratia
Out breaks of clinical mastitis
Summer mastitis
Most common in Europe
Actinomyces pyogenes + Peptostreptococcus indolicus
Non-lactating heifers and cows at pasture in the summer months and more common during wet weather
Fly borne ??
Severe systemic reaction and Loss function
Abcess develop

47. Bacterial Infection: Other organisms
Mycoplasma mastitis
Clinically severe mastitis
Rarely systemic involvement
All ages & all stages of lactation
Post calved cows show more severe signs.
Long-term persistence in udder (up to 13 mths)
Some cows can shed the organism without clinical signs.
Normal secretion in the early stage of infection
Flaky material settles out leaving a turbid
Whey-like supernatant fluid
Very high SCC

48. How is mastitis diagnosed ?
Physical examination
Signs of inflammation
Empty udder
Differences in firmness
Unbalanced quarters
Cowside tests
California Mastitis test
Cultured Analysis
The most reliable and accurate method

49. Treatment Clinical mastitis Treatment with penicillins
Strip quarter every 2 hours
Oxytocin valuable
high temp, give NSAIDs
Seek veterinary assistance
Treatment with penicillins
Subclinical mastitis
Questionable

50. กล้ามเนื้อหูรูด
รูหัวนม

54. สอดปลายเข็มยาว1/8 – 1/4 นิ้ว ผ่านทางรูหัวนมเท่านั้น
ปล่อยยาบางส่วนที่ตำแหน่งติดรูหัวนม
และปล่อยยาที่เหลือทั้งหมด
ที่ตำแหน่งห่างออกไป

55. Partial Insertion เข็มสั้น เข็มยาว ห้ามสอดเข็มยาวเข้าจนสุดรูหัวนม
เพราะจะทำลายไขที่ปิดรูหัวนม
ทำให้เชื้อภายนอกมีโอกาสเข้าสู่เต้านม
ได้ง่ายยิ่งขึ้น

57. Standardized Milking Procedures
Stanchion/ Tie stall
Ware gloves
Wipe off excess dry manure, straw and bedding
Strip each teat into a stripcup
Dip teats with an approved pre-dip
Allow the pre-dip to react for at least 30 sec.
Parlor
Wear Gloves
Wipe off excess dry manure, straw and bedding
Strip each teat into a stripcup
Dip teats with an approved pre-dip Dip 3-4 cows
Allow the pre-dip to react for at least 30 sec.

58. Standardized Milking Procedures
Stanchion/ Tiestall
Clean teat and teat ends using single paper towel or individual towel cloth
The teats must be dried for at least 15 sec
Attach milking machines immediately after teats are dried
Dip teats with post-dip immediately after milking
Parlor
Return to the first cow and clean teat and teat ends using a single paper towel or individual towel cloth
The teats must be dried for at least 15 sec
Attach milking machines immediately after teats are dried
Dip teats with post-dip immediately after milking

59. Detection of Mastitis Visualization and palpation of the udder
Detection of Somatic Cells
California Mastitis Test
N-acetyl-ß-D-glucosaminidase (NAGase)
- a lysosomal enzyme which increases in milk
when mastitis is present

60. Indirect chemical tests to detect mastitis
Electrical conductivity: Sodium and Chloride ions
A radial immunodiffusion test : Serum albumin concentration increases if epithelium damage is present.
An anti-trypsin test: Anti-trypsin activity tends to naturally high at the beginning of a lactation the values are high only if serum anti-trypsin has leaked through damaged mammary epithelium.

61. California Mastitis Test (CMT)
The CMT reagent reacts with genetic material of somatic cells present in milk to form a gel.
A plastic paddle having four shallow cups marked A, B, C and D for easy identification of the individual quarter.
Approximately 1/2 teaspoon (2 cc) of milk is. An equal amount of the CMT reagent is added to the milk.
A circular rotating to thoroughly mix the contents. Score in approximately ten seconds while still rotating.
Read the test quickly as the reaction tends to disintegrate after about 20 seconds.
Rinse the paddle thoroughly with water and it is ready for the next test.

62. Advantages of CMT Fairly accurate in measuring SCC in milk
Primarily developed for sampling quarters, it can also be used on "bucket" and "bulk tank" milk samples.
Foreign material does not interfere with the test.
It is inexpensive, simple, and little equipment is needed.
Easy clean-up after each test--simply rinse with water.
Environmental temperature changes have little effect on the CMT as long as the milk has been refrigerated and is not over two days old.
Herd mastitis levels can be estimated from tank CMTs. A CMT of 2 or 3 on tank milk indicates a probable high percent of infected cows.

63. Disadvantages of CMT
Scoring the test may vary between individual testers. It is necessary to be as consistent as possible to insure uniform results.
Scores represent a range of leucocyte content rather than an exact count.
False positive reactions occur frequently on cows that have been fresh less than ten days, or on cows that are nearly dry. These animals should be tested closer to the middle of the lactation.
Occasionally, acute clinical mastitis milk will not score positive due to the destruction of leucocytes by toxins (poisons) from the infecting organism.

64. Correlation between the California mastitis test result and the somatic cell count.
CMT score
Interpretation
Visible reaction
Total cell count (/ml)
Negative
Milk fluid and normal
0-200,000
0-25% neutrophils T
Trace
Slight precipitation
150, ,000
30-40% neutrophils 1
Weak positive
Distinct precipitation but no gel formation
400,000-1,500,000
40-60% neutrophils 2
Distinct positive
Mixture thickens with a gel formation
800,000-5,000,000
60-70% neutrophils 3
Strong positive
Viscosity greatly increased. Strong gel that is cohesive with a convex surface.
>5,000,000
70-80% neutrophils

65. Steps involved in employing HACCP-based concepts for establishing proper milking procedures
Educate owners and milkers about implementing a standardized milking procedure (Benefits !!!!!!)
IF a dairy farm initiates and shows sustained interest
Establish ground rules
They will have to be proactive and adopt changes
TEAM EFFORT !!!

66. STEP TWO Establish a team ( owner, milkers, veterinarian, facilitator)
Mission statement
Goals and timeline
Written Procedures
Protocols
Critical Limits ( SCC > 250,000)
Recording Keeping
Milking time/milking
Bulk Tank Temp; end of 1 hr of milking
Sanitation
Schedule team meetings to review the process

67. STEP THREE STEP FOUR STEP FIVE
Train milkers and owners in implementing the standardized milking procedure
STEP FOUR
Monitor the application of the standardized milking procedure
Floor tests (each step is a critical point !)
Laboratory tests (SPC or BTSCC)
Monitor records
STEP FIVE
Establish corrective actions to be implemented if milk quality critical limits have exceeded.

68. Factors Affecting Somatic Cell Counts
1. Mastitis (Udder infection)
2. Teat or udder injury
3. Number of quarters with mastitis
4. Age of cow
5. Stage of lactation
6. Season
7. Stress
8. Day to day variation
9. Technical factors
10. Management factors

69. Uses of SCC on Individual Cows for Management Decisions
1. Milk Culture and Sensitivity Testing
2. Treatment During Lactation
3. Drying Cows Off Early
4. Culling

70. 1. Milk Culture and Sensitivity Testing
High SCC >500,000 cells/ml
Very useful when:
High SCC two or more tests
Beginning of lactation

71. 2. Treatment During Lactation
Strep. agalactiae infection
Very few cases of subclinical mastitis
High SCC vs culture vs sensitivity

72. 3. Drying Cows Off Early The best method of eliminating infection
High SCC and relatively low production
There is evidence to suggest that a repeat dry treatment 3 weeks after the first therapy could increase success rate.
Teat dipping for 10 days after lasting milking and for 10 days prior to calving

73. 4. Culling Persistently high SCC from lactation to lactation
Staph. aureus or Mycoplasma spp.
Milk production

74. 5. Milking Routine
High SCC cow could be milked last or the milking machines could be sanitized after milking.

75. Mastitis Bulk Tank Culture Report Interpretation
Type of Bacteria
Usual Infection Cause
Major Means of Spread
Mastitis Control
Strep agalactiae
Infected udders of other cows in herd
Cow-to-cow by contaminated udder wash
Use separate towels to wash/dry; Teat dipping; dry cow treatment; eradicate in special cases
Staph aureus
Infected udders of other cows, contaminated bedding from milk of infected cows
Cow-to-cow by contaminated udder wash rag, milker’s hands contaminated milking equipment , and improperly functioning equipment
Use separate towels to wash/dry; Teat dipping; dry cow treatment; milk infected cow last, cull chronically infected cows
Mycoplasma
Infected udders of other cows, often from infected purchased cows/heifers
Cow-to-cow by hands of milkers, equipment, and common towels. Aerosol transmission from animals with respiratory signs may also occur. Or the bacteria can move from a respiratory tract infection to the udder or joints.
Careful purchasing of replacement cattle, using bulk tank and cow culturing to monitor herd status and clinical cows. Use separate towels to wash/dry; teat dipping; dry cow treatment; milk infected cows last, cull any positive clinical case.

76. Mastitis Bulk Tank Culture Report Interpretation
Type of Bacteria
Usual Infection Cause
Major Means of Spread
Mastitis Control
Non-ag Streps
Environment of cow
Environment of the cow by; wet dirty lots, contaminated bedding, milking wet cows, poor cow prep, milking machine air slips
Improve stall and lots sanitation; milk clean dry cows, avoid air leaks and liner slips, changes bedding frequently. Keep cows standing after milking.
Coliforms
Environment of the cow by; wet dirty lots, contaminated bedding, milking wet cows, poor cow prep, milking machine air slips. Hot humid weather.
Staph species
Poor teat dip coverage, poor cow prep, old bedding.
Consistent teat dipping, adequate cow prep, and more frequent bedding change.

87. Good Milking Procedures
1. Provide Cows with a Clean, Stress-Free Environment
2. Check Foremilk and Udder for Mastitis
3. Wash Teats and Lower Surface of the Udder with a Warm Sanitizing Solution
4. Use a Premilking Teat Dip (Optional)
5. Dry Teats Thoroughly
6. Attach Teat Cups within 1 min.
7. Adjust Milking Units as Necessary
8. Shut Off Vacuum Before Removing Teat Cups
9. Dip Teats with a Safe and Effective Teat Dip
10. Disinfect Teat Cups Between Cows (Optional)

94. Problem Herd Handling Problem Solving Techniques
One or more specialists: vet, fieldman, extension agent or milking machine dealer
A visual inspection of the general environment
Good detectives
Specific approach

95. Problem Herd Handling High Incidence of Clinical Mastitis and High SCC
Detection and discarding of visibly abnormal milk.
Not milking fresh cows with cows that have clinical mastitis
Collection of milk samples and culturing in a diagnostic laboratory.
Treatment of selected cows, especially those infected with Streptococcus agalactiae.
Culling of cows with chronic infections, particularly those caused by Staphylococcus aureus, environmental streptococci, Nocardia asteriodes, and Mycoplasma species.
Drying off of selected cows and dry treating.
Correction of deficiencies in management and environment.

96. Problem Herd Handling Upgrading of milking equipment
(Continued)
Upgrading of milking equipment
Correction of deficiencies in milking hygiene.
Improvement in the manner in which milking machines are used.
Initiation of predipping.
Strengthening of postmilking teat dip procedures.
Arranging for fresh feed to be available when cows exit the milking parlor or barn so they will be encouraged to stand for at least 1 hour after milking to provide time for the teat canal to close tightly.
Segregation of infected cows.
Initiation of backflushing, particularly if the problem is caused by contagious microorganisms such as Staphylococcus aureus, Streptococcus agalactiae, or Mycoplasma species.

97. Problem Herd Handling High Bacteria Counts
>10,000 /ml, Streptococci >75%  Infected Udder
Streptococci < 25%  Improper Cleaning of Milking Equipment, Poor Udder Preparation and Poor Cooling of Milk
High Streptococci & High Staphylococci + Coliforms + Spore Formers + Other Organisms A dual problem of infected cows and poor udder preparation.
>15,000 /ml of Staphylococci  Poor cooling of milk
High coliform counts  Broken teat cup liners, low water temperature, milkstone on milk-contact surfaces and failure to use correct chemicals for cleaning milking equipment
Large number of coliforms, staphylococci, and environmental streptococci Faulty cooling of the milk

98. Mastitis Prevention Principles
1. Milk cow with clean, dry teats and teat ends.
Impact: Milk quality, environmental mastitis, liner slips, milk out and parlor throughput
2. Prevent transfer of pathogens from cow to cow during milking.
Impact: Contagious mastitis, milk quality
3. Prevent injury to the teats during milking.
Impact: Mastitis, milk out, parlor throughput

99. Mastitis Prevention Principles
4. Provide an environment that allows the cows to remain clean between milking.
Impact: Environmental mastitis, milk quality, parlor throughput, cow comfort
5. Early detection of new infections (clinical and subclinical).
Impact: Response to treatment, chronic infections, culling
6. Proper use of medications.
Impact: Success of treatment, cost control, residues in milk and meat

100. Mastitis Prevention Principles
7. Control duration of infections.
Impact: Decreased prevalence, decreased culling
8. Monitor mastitis status.
Impact: Prevent outbreaks, culling information
9. Raise mastitis free replacements.
Impact: Permit culling for production, reduced herd prevalence
10. Assume all purchased replacements are infected.
Impact: Control introduction of new pathogens

101. Mastitis Prevention Principles
11. Provide adequate nutrition to preclude increased susceptibility to mastitis.
Impact: Control new infection rate
12. Fly control.
Impact: Teat end injury, new infection rate
13. Provide routine milker training
Impact: All areas of mastitis prevention and control, milk quality
14. Assigned responsibilities for all areas of mastitis prevention.
Impact: Job knowledge, shared responsibility, improved compliance

102. Question?