Mastitis Flashcards

(196 cards)

1
Q

Environmental mastitis pathogens

A

E.coli
Streptococcus uberis
Klebsiella

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2
Q

Contagious mastitis pathogens

A
Streptococcus uberis
Streptococcus dysgalactiae 
Streptococcus agalactiae
Staphylococcus aureus 
Coagulase negative staphylococci
Mycoplasma
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3
Q

How does sub-clinical mastitis present?

A

No visible signs
Changes in SCC
Reduced milk quality and yield

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4
Q

How can you grade clinical mastitis?

A

1a - mild changes in the milk
1b - acute milk changes + udder hot and painful
2c - chronic changes in milk + udder hard and lumpy
3 - changes in the milk and udder + cow sick

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5
Q

What are the outcomes of mastitis infection?

A
  1. Clear the infection and return to normal milk production
  2. Persistently infected - spreads amongst the heard
  3. Permanent damage to the udder causes a reduced milk yield
  4. Death - toxaemia
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6
Q

How can the the teat skin be damaged to predispose a cow to mastitis? And how can you protect the teat skin?

A

Bruising, chapping, trauma
Teat lesions
Damage by the milking machine

Methods to protect the teat skin:

  • post-milking teat dipping
  • prompt treatment of teat lesions
  • good milking machine function
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7
Q

When can bacteria invade the teat canal? And how is the teat canal damaged?

A

When open during and after milking - takes about 20-30 minutes to close
Keratin forms a seal over the teat end when the cow is dried off

Damage to the teat canal occurs by:

  • milking machines
  • trauma to the teats
  • teat lesions
  • teat cannula
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8
Q

What causes Teat end hyper keratosis?

A

Excessive milking vacuums
Worn teat liners
Faulty pulsations
Liner type

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9
Q

When are cows at most risk of acquiring new mastitis infections?

A

Early dry period

Late dry period

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10
Q

When do most clinical mastitis cases occur?

A

1st 6 weeks post calving

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11
Q

Why are cows predisposed to acquiring mastitis infections in the dry period?

A
Cessation of milking - increased intra-mammary pressure and widening of the teat canal
Bacteria not flushed out 
No teat dipping
Poor formation of the keratin plug 
WBC function is reduced
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12
Q

What nutrition factors can lead to mastitis?

A

Negative energy balance
Vitamin E and Selenium
Sub-acute Rumenal Acidosis
Hypocalcaemia

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13
Q

What does the mastitis vaccine protect against?

A

Staph aureus
Coliforms
Coagulase negative staphylococci

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14
Q

What are the housing requirements for a cow?

A
Lying area
Loading area
Feed space
Safe flooring and passageways
Water supply
Slurry handling
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15
Q

How much loafing area should cows have?

A

120% of cubicle area

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16
Q

How much feed barrier space must a cow have?

A

60cm per milking cow

90 cm per dry cow

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17
Q

How much water space must a cow have?

A

10cm per cow

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18
Q

How much lunge space does a cow need?

A

0.7 - 1m lunge space

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19
Q

What does the stack effect require?

A

Inlet above the outlet

Sufficient body mass to generate heat to move the air

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20
Q

5 freedoms

A
Freedom from hunger and thirst
Freedom from pain injury and disease
Freedom from discomfort 
Freedom to express normal behaviour 
Freedom from fear and distress
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21
Q

What lighting should you provide for cows?

A

16-18 hours per day
Increases yield by 2 L
10% of the roof area should be transparent

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22
Q

What is the stocking density of loose housing?

A

1.3 m squared / 1000 kg of herd milk production

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23
Q

What are advantages and disadvantages of loose cow housing?

A

Comfortable so reduced lameness
Increased requirement for trimming

Straw is expensive
Increases Streptococcus uberis risk
Poor hygiene
High cell counts

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24
Q

How should you maintain loose straw housing?

A

Clean out every 2 weeks
Bale down 3 times a week
Store dry bedding under cover
Have a sand drainage layer that can be replaced every few months
Completely clean out straw every 2 weeks
Clear divide between bedding and standing

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25
When should a farmer increase cleaning frequency?
Disease Squelching Bedding hot to touch
26
What is minimum water requirement of a cow?
15-20L
27
What should you aim to deliver in a cubicle design?
Comfortable lying and standing time Slight curb incline kerb-front Dung passed over the kerb with minimum deposited on the rear Minimise pathogen growth with the choice of bedding
28
How long should a cubicle be?
2.3-2.4m
29
Height of the head rail
1.4m
30
What width of a cubicle is there?
1.15 - 1.2m
31
What should the kerb height be?
10cm
32
What slope kerb should you have on a cubicle?
2-3%
33
What lying length should you have in a cubicle?
1.7m
34
What disease will you see with poor cubicle design?
Lameness Mastitis Neck lesions - feed barrier Hock and stifles - problems with bedding
35
What does a cow reverse into a cubicle tell you?
Too high a kerb
36
What does a cow standing with its hind feet in the passageway tell you?
Head rail too near kerb
37
What does a cow lying diagonally in the cubicle tell you?
Cubicles too wide
38
What is the cow comfort quotient?
Number of cows correctly interacting with the cubicle / Number of cows interacting with a cubicle at all X 100 Aim for over 80% Less than 50% poor
39
What do hock lesions indicate?
Insufficient substrate Cubicle too short Cubicles with solid rear leg supports Poor quality shavings
40
What does a half in half out posture predispose to?
Solar ulcers
41
What does standing time in slurry cause?
Heel horn erosion and digital dermatitis
42
What does dung, urine and milk deposited on the cubicle predispose to?
Environmental mastitis
43
How much substrate should a cubicle have?
3kg per day
44
What are the advantages and disadvantages of substrates?
Sand = best - hygienic Deep straw = streptococcus uberis risk Paper ash = hardens when wet
45
How frequently should scrapers be run?
Every couple of hours
46
How can you design a building to maximise comfort?
2 rows of cubicles per feed barrier 3m passage between rows of cubicles 4.3m passage between a row of cubicles and feed barrier space 2.4 passageway between rows of 20 cubicles
47
How can you ensure cow comfort during feeding?
``` Adequate feed rail height and feed barrier offset forwards Palatable feed Keep feed pushed up and within reach Brushes - enrichment Sprinklers to cool ```
48
How can you ensure good ventilation?
3/4 inch gaps between roof slots Fans Open ridge plus chimney
49
What pressure should the milking vacuum be regulated at?
42-48 kpa
50
What speed should the vaccum pulsator be set at?
60 pulsations per minute
51
What is the vaccum on to off ratio?
2:1
52
How does the milking machine contribute to mastitis?
Damage to the teat ends | Acts as a vectors for spread of mastitis
53
How does damage to the teat skin occur during milking?
Worn / hard liners Inadequate rest phase in pulsators or pulsations too fast Excess vacuum Inadequate emolient in the post-dip
54
What leads to teat sphincter hyperkeratosis?
``` Excess vacuum Fluctuating vacuums Over-milking Faulty liners Poor pre-milking teat preparation - not enough milk let down ```
55
How does the milking machine transfer mastitis infection?
Contamination of liners Wet milking - Inadequate vacuum - Fluctuating vacuum - Blocked air bleed
56
What common problems are encountered with milking machines?
Vacuum problems - hissing sound Fluctuating / inadequate vacuum - holes in tubing, liner slip Blocked air bleeds on the cluster unit - flooding of the claw piece Faulty pulsation - too fast, inadequate rest phase, holes in tubing
57
What simple tests can you perform to assess the function of the milking machine?
Examine the cluster - blocked air bleed - cleanliness of liners - wear of liners - perishing holes in tubing ``` Note the level of the vacuum gage - 42-48 Watch whilst milking - liner slip - need smaller liner - oedematous teats - need a bigger liner Watch cows - paddling or kicking Teat score Ask wash up routine Ask when last serviced ```
58
What factors should asses in the parlour routine?
Gloves Pre-milking teat preparation - fore-milking, teat disinfection Post-milking teat preparation Loafing time Parlours management - milking order, cluster disinfection Parlour wash up routine
59
What does fore-milking do?
Legal requirement Milk let down Allows early detection of mastitis
60
What benefits does teat cleaning and disinfection have?
Reduces environmental bacterial contamination Stimulates let down Reduce the risk of strep uberis and e.coli Good for public health
61
What are some common teat disinfectants and what should you check regarding their use?
Chlorhexidine Iodophors Concentration Contact time Teat coverage
62
How can you assess the effective of teat cleaning and disinfection?
Milk filter analysis / bacteriology
63
What does pre-milking cleaning and disinfection prevent?
Environmental mastitis
64
What does post-milking teat disinfection prevent?
Contagious mastitis - staph aures, strep dysgalactiae, strep agalactiae Disinfectants - iodine, chlorhexidine, lactic acid Emollients Dye Sticking agents
65
How can post-milking teat dips be applied?
Dip pot - can spread infection is disinfectant is ineffective Spray Cluster
66
How much loading time should a cow have to allow for the teat sphincter to close?
30 minutes Prevents environmental infections Allows closure of the teat sphincter Keep in a clean area
67
What milking order should you recommend to a farmer?
``` Heifers Fresh calvers High yielders Low yielders High cell count cows Mastitic cows ``` STILL NEED TO DISINFECT THE CLUSTER BETWEEN COWS
68
How should a farmer manage high cell count and mastitic cows?
Red tail tape Milk last in the order Clean and disinfect the cluster between each cow
69
What parlour wash routine should you recommend?
``` Clean milk out of the clusters Cold rinse Hot wash - more than 60c for clusters, 85-90c for tank - 10-12L of water Rinse with hypochlorite Acid and alkali washes ```
70
How can you assess the efficacy of the milking parlour in preventing mastitis?
Milking machine assessment - observe cows, observe vacuum gage, listen for liner slip Teat score a minimum of 20% of the herd Observe parlour hygiene routines Management of high cell count cows and mastitic cows Parlour wash routine Take milk samples for bacteriology
71
IWhat is the mastitis 5 point control plan?
1. Post milking teat disinfection 2. Dry cow therapy - intra-mammary tubes and teat sealants 3. Prompt treatment of clinical cases 4. Cull chronic cases 5. Maintain and use the milking machine properly Effective at control CONTAGIOUS mastitis, but not effective for controlling environmental mastitis
72
What are the most common causative agents of mastitis?
Streptococcus uberis - contagious and environmental E.coli - environmental Staphylococcus aureus - contagious
73
Online a mastitis action plan.
``` Housing - dry, clean and well ventilated Good parlour routine - wearing gloves - pre milking and teat disinfection - good milking machine maintenance - post-milking teat disinfection - loafing time - maintain good teat condition - good milking order Dry cow management - therapy, housing, nutrition Nutrition - avoid SARA, NEB, provide vit E and selenium Prevent milk fever Cull chronic cases Regular monitoring Fly control Good record keeping ```
74
How should you control contagious mastitis pathogens?
Control spread during milking - post milking teat dipping - properly functioning milking machine - milking order - disinfect cluster Reduce levels of infection in the herd by treating clinical cases - strep agalactiae and dysgalactiae - penicillin sensitive - dry cow therapy - staphylococcus aureus is more difficult to control
75
How should you approach treating cases of staphylococcus aureus mastitis?
Need to treat for longer periods - lives intra-cellularly Culture and sensitivity required - 1/3 penicillin resistant Infections occurring at the end of lactation - dry off early - intra-mammary Ab +/- systemic antibiotics Infections occurring during lactation - 5-8 days of intra-mammary antibiotics - systemic antibiotics Cull chronic cases
76
When do E.coli infections normally present?
Most infections acquired in the dry period and early lactation Hygiene during these periods is essential
77
What factors can you control to decrease the incidence of E.coli mastitis?
Housing hygiene and comfort - especially dry, fresh calved and early lactation Pre-milking teat disinfection - high concentration of iodine Loafing times - 30 minutes Dry cow management - nutrition, therapy Startvac vaccine
78
What measures can you take to control Strep uberis mastitis?
Often picked up in dry period and early lactation Step uberis acts as both a contagious and environmental pathogen ``` Housing - dry period and early lactation Pre-milking teat disinfection Loafing times Effective therapy Dry cow management Parlour hygiene ```
79
What statistics can you look at when assessing a herd mastitis problem?
``` Number of clinical cases per 100 cows per year % herd affected Recurrence rate Seasonality Stage of lactation ```
80
What is the sensitivity of bacterial culture vs PCR?
70% bacterial culture | 92% PCR
81
What should you assess with hygiene scoring?
Cleanliness of the cow - below the hock - upper leg and flank - udder Less than 25% scores 3 or 4
82
What scoring methods can you use to assess nutrition?
Condition scores Faecal scores Look at the diet
83
What percentage of the herd should you teat score?
At least 25%
84
What can you advise a farmer to reduce their SCC so they can still sell their milk?
Identify the worst affected cows and remove their milk from the bulk tank
85
How can you select an individual cow for bacteriology testing?
Clinical cases | High SCC cows
86
What factors should you consider when investigating a contagious mastitis problem?
Poor parlour hygiene Transmission by the milking machine Poor management of high cell count cows and clinical cases Ineffective dry cow and lactating cow therapies
87
What factors should you consider when dealing with an environmental mastitis problem?
``` Bad housing Poor parlour hygiene Dry cow management Dry cow therapy Insufficient teat preparation ```
88
What systemic disease can cause teat lesions?
Foot and mouth disease Malignant catarrhal fever Photosensitisation
89
What infectious teat lesions are there?
``` Warts - bovine papilloma virus Pseudo cowpox Bovine herpes mammilitis Black spot Cow pox Udder impetigo ```
90
What non-infectious teat lesions are there?
``` Photosensitisation Chapped teats Cut teats Teat pea Teat stenosis Blind teats ```
91
How can you diagnose teat lesions?
Dry scabs for electron microscopy | Bovine herpes mammilitis serology
92
What is the general treatment for teat lesions?
Teat cannula - to allow milk drainage Intra-mammary antibiotics Emollients Antiseptics
93
Teat warts / bovine papillomatosis
Bovine papilloma virus Seen in young heifers Spread by files - harbour bacteria - predispose to mastitis - cause poor liner attachment - teat end impacts and difficulty milking - pain Tx: most self cure Can be removed by laser or cryo Autogenous vaccine for severe cases Prevention - fly control - synthetic pyrethroid ear tags / pour ons, permethrin
94
Pseudo cowpox
Parapox virus Curricular, or horse shoe shaped non-painful scabby lesions Spreads throughout the herd Tx: post-milking teat dipping Self cure but may recurr
95
Bovine herpes mammilitis
Bovine herpes virus 2 VERY PAINFUL TEAT ULCERS Slow to heal - takes weeks - immunity once healed Seen in 1st lactation heifers Transmission via contaminated clusters Treatment: improve parlour hygiene Acyclovir
96
Cow pox
Last occured in 1978 Orthopox virus Spread by cats Lesions appear the same as bovine herpes virus - very painful and slow healing
97
Black spot
Excessive vaccum causes blue teats and teat end eversion - predisposes to Fusobacterium necrophorum infection Causes black spots on teats Treatment: adjust the vacuum Oxytetracycline spray Teat cannula - check the milking machine
98
Udder or teat impetigo
Staphylococcus aureus Pustular lesions on the teat and udder skin Can spread to milkers Control: post milking teat dipping, antiseptic creams
99
Photosensitisation and sunburn
The teats are usually the first place to show Photosensitisation Ingestion of photosensitising plants - St John's wart Liver disease - chronic fluke, ragwort ingestion Tx: remove from sunlight, NSAIDs supportive treatment
100
Chapped teats
Painful Poor teat skin care - no emollients in dips Worn liners Calf sucking Tx: emollients and place a teat cannula so you don't have to put the cluster on
101
What is required of a post-milking teat dip?
Correct anti-septic to kill contagious mastitis pathogens Emolient Persists on the teat for 30mins (loafing time)
102
Teat pea
Pedunculated granuloma attached to the wall of the teat canal - blocks milk flow Treatment - removal by hudsons spiral - rotating up the end of the teat canal to pull out granuloma - granuloma milked out - place a teat canal MUST GIVE PROPHYLACTIC ANTIBIOTICS TO PREVENT MASTITIS
103
Teat stenosis
Usually secondary to trauma or summer mastitis Guarded prognosis - scar may reform Tx: sedation and local anaesthetic - painful use a teat knife to open up the teat canal teat cannula
104
Blind teats in heifers
Should be left alone - there is no milk in there
105
How should you treat a teat laceration?
Sedate with xylazine Restrain in a foot trimming crush and raise leg Clean teat and wound thoroughly Apply a local anaesthetic nerve block - teat lumen block / ring block If very superficial - glue Clean and debride Close subcutaneous layer with a continuous suture Suture skin with a simple interrupted pattern (vertical mattress in diagram) Guarded prognosis - may lead to teat stenosis
106
How can you treat supernumerary teats in a calf under 2 months old?
At the same time as disbudding Put in a dog sitting position and hobble the hindlimbs Can be removed with scissors without local anaesthetic
107
How can you remove a supernumerary teat in an older calf?
Crush and lift leg Or sedate and cast and apply kick bar Do in parlour Give local anaesthetic Remove with scissors or emasculators
108
How can you know how much sub-clinical mastitis there is in a herd?
California milk test | Milk recording
109
If you are going to submit a milk filter for bacteriology, what must you do first?
Remove it at the end of milking, before the wash cycle
110
What cell counts does the California milk test go positive for?
Over 300,000 cells
111
What things can you assess when investigating mastitis?
In parlour - fore milking - visible milk changes - clinical signs - palpation, cow response, cow health - California milk test - in line filters - submit for bacteriology Clinical case records - get farmer to make a table and record Cow ID, date, quarter affected, treatment, cell count at 7 days Somatic cell counts - individual or pooled - a few counts contribute to most of the cell count - want to identify these cows and exclude them from the bulk tank Bulk tank bactoscan Bacteriology - individual or bulk tanks Multiplex PCR - more sensitive, used to identify penicillin resistant staphylococcus aureus
112
What is the target for number of clinical cases per year?
Less than 30 cases per 100 cows per year | Average 45-60
113
What is the target for annual incidence of mastitis?
Less than 20% of herd affected
114
What is the target for recurrence rate of clinical mastitis?
Less than 10% of cases recurr
115
What does a high recurrence rate (over 10%) suggest?
Staphylococcus aureus Streptococcus uberis Problems with treatment - eg penicillin resistance in S. aureus Teat end damage
116
What should be a farmers target milking cow intra-mammary antibiotic use age?
Less than 140 per 100 cows
117
What do milk recording systems record?
On a monthly basis High cell count cows Chronically infected cows Stage of lactation
118
How can you determine which cows are affected based on individual SCC?
Under 100,000 - infection unlikely 100,000 - 200,000 - infection in one quarter with minor pathogen 200,000 - infection in quarter with major pathogen
119
How can you quickly fix a bulk milk tank result over 400,000?
Prevent milk from high cell count cows entering the tank - identify individual cows using NMR results - California milk test in parlour - identifies cows over 300,000
120
What does a high bactoscan result indicate?
High bacteria numbers in milk - high levels of mastitis - poor plant cleaning - dirty udder / teats - insufficient pre-milking teat preparation - poor housing hygiene
121
What level of bactoscan will the milk be excluded from supply?
Exceeding 50,000
122
What must you ensure when transporting bulk milk samples for bacteriology?
Keep sample cool on ice
123
What can results from bulk tank bacteriology tell you?
Total bacterial count Cell count LPC thermoduric count - cleanliness of the plant Coliform count - adequacy of pre milking teat preparation Total staphylococcal count Staphylococcus aureus Strep uberis, dysgalactiae and agalactiae
124
What should you advise a farmer to do with his clinical mastitis cases and high cell count cows before treatment?
Take sterile milk samples, freeze and submit for bacteriology and culture and sensitivity Keep a rolling 12 months of samples in the freezer - culture some occasional when there is a problem
125
Hat are the main limitations of individual cow bacteriology?
Some pathogens are only intermittently shed - S. aureus Contaminated samples Some animals that have received antibiotic treatment show no growth (last 7 days)
126
What should you do if there is no growth on bacteriology?
Repeat sampling | PCR
127
How can you interpret bacteriology results?
Pure growth of bacteria - causal Major pathogen and minor pathogen - major causal More than one minor pathogen - mixed infection More than 3 bacteria present - contamination Negative - intermittently shedding or on antibiotics
128
What would you suspect as a causative agent if you have chronically high SCC?
Gram positive causative agent | Eg: staph aureus
129
What would you suspect as the causative agent when there is a quick spike in SCC followed by recovery?
Gram negative
130
What would you expect if you had lots of clinical cases occurring in the first month post-calving?
Infection picked up in the dry period
131
What would you expect if you had lots of clinical cases but low herd SCC?
Gram -ve
132
How does staphylococcus aureus appear on culture?
Gram positive cocci Coagulase positive Forms white colonies on blood agar, with a ring of haemolysis Intra-cellular bacteria, produces abscesses = recurrent - intermittent shedding 1/3 of strains produce beta lactamases - penicillin resistant
133
What is the most common contagious mastitis pathogen?
Staphylococcus aureus
134
How does staphylococcus aureus mastitis present?
Sub-clinical - persistently high SCC Clinical grade 2a (acute) - udder, hot swollen and painful Clinical grade 2c (chronic) - abscess formation and fibrosis Clinical grade 3 (gangrenous) - systemically ill cow
135
How does gangrenous mastitis due to staph aureus present?
``` Freshly calved (immunosuppressed) Systemically ill - toxaemic Gangrene of udder tissue Udder cold, blue and necrotic Milk often dark red and bloody ```
136
How should you treat gangrenous mastitis?
``` IVFT - 5L 7.2% NaCl, followed by 4x15L buckets of water NSAIDs - ketoprofen, meloxicam Strip out affected quarter Oxytocin Systemic antibiotics ``` Consider PTS
137
What are poor prognostic indicators in staph aureus mastitis?
Older cows, more than 5 lactations 3 or more repeat infections Chronically high SCC Penicillin resistance
138
How can you control staph aureus mastitis in a herd?
Treat cases Cull chronic cows (3 or more cases) Dry cow therapy Check any introduced animals - SCC, examine udder Good parlour hygiene - wear gloves - do not use a common udder cloth - early detection and treatment - post-milking teat disinfection - mastitic cows or chronic high cell counts milked last - maintain the milking machine correctly - liners and vacuums
139
How can you identify streptococcus agalactiae on culture?
Gram positive cocci Non-haemolytic Very small pin prick colonies
140
What stages of mastitis does streptococcus agalactiae cause?
Sub clinical - high SCC Grade 1 - mild milk changes Grade 2 - hot, hard, swollen udder, mild milk changes
141
How can you treat streptococcus agalactiae?
Intra-mammary penicillin | Blitz therapy to eliminate from the herd
142
How does streptococcus dysgalactiae appear on culture?
Gram positive cocci Small pin prick colonies on Edwards Medium Partial haemolysis, green zone Alpha haemolysis
143
What type of mastitis does streptococcus dysgalactiae cause?
Part of summer mastitis Persistent infections Usually associated with teat condition and milking pulsator problems
144
How can you treat streptococcus dysgalactiae?
Responds well to penicillin Address problems with the milking machine - vacuum / pulsator problems
145
How does mycoplasma mastitis usually present?
M. bovis, M. californicum - m.bovis also causes infertility, metritis, joint ill and otitis media, keratoconjunctivitis and pneumonia (Don't feed milk to calves) Marked milk drop Swollen quarter Cow not systemically ill Highly contagious in the parlour and aerosol spread
146
How can you treat mycoplasma mastitis?
``` Poor response to antibiotics - no cell wall Milked last and cluster disinfected Or cull - destroys the quarter - pathogen may be shed for life ```
147
What should you consider of you culture coagulase negative staphylococci?
Minor pathogen - may be a skin contaminant in a milk sample Mild disease that causes high SCC Repeat culture Tx: spontaneous cure frequent Respond well to penicillin
148
How does E.coli appear on culture?
Gram negative rods Creamy white colonies on blood agar Haemolytic and non-haemolytic Metallic green sheen on Eosin Methylene Blue
149
What grades of mastitis does E.coli cause?
Clinical cases often seen during the 6 weeks of lactation - infections acquire during the dry and periparturient period Bacteria produces LPS endotoxin = damage to secretory and vascular tissue ``` Grade 1 - clots in milk - self cure Grade 2 - clots in milk, hot hard and painful udder Grade 3 - common = toxic mastitis - very sick, in endotoxaemic shock - variable udder consistency - milk varies from clots to blood IMPORTANT DDX IN DOWNER COW POST-CALVING ```
150
How should you treat grade 1 and 2 E.coli mastitis?
Self cure | Or intra-mammary antibiotic eg aminoglycosides
151
How should you treat a grade 3 toxic e.coli mastitis?
3-5L of 7.2% NaCl IV, followed by 4 x 15L buckets of water NSAIDs - ketoprofen, meloxicam, flunixin Strip out quarter q 4-6 h Oxytocin Intra-mammary antibiotics - trimethoprim sulphonamides, aminoglycoside Systemic antibiotics - oxytetracycline
152
How can a farmer control E.coli mastitis in his herd?
Important - infection occurs in dry period and early lactation Improved housing hygiene and nutrition Pre-milking teat disinfection Clean loafing area for 30mins after milking Dry cow therapy - aminoglycoside and teat sealant Startvac vaccination
153
What does startvac protect against and when should it be given?
3 doses 1. 45 days pre-calving 2. 10 days before calving 3. 7-8 weeks post calving E.coli, staph aureus, coliforms, coagulase negative staphylococci Reduces the incidence of subclinical mastitis Reduces the incidence and severity of clinical mastitis
154
How does streptococcus uberis appear on culture?
Non-haemolytic Brown colonies on Edwards medium Gram positive cocci - chains Blood agar - Alfa haemolytic colonies
155
What clinical presentations does streptococcus uberis mastitis cause?
Straw bedding (Environmental and contagious) All grades of mastitis can occur Sub clinical infection common - high SCC Chronic and recurrent infections are common
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How should you treat strep uberis mastitis?
Can be difficult to eliminate from the udder Intra-mammary - penicillin (penethamate good penetration) Systemic antibiotics - tylosin (macrolide) Dry off early with antibiotics if nearing end of lactation Cull chronic cases
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How does klebsiella present?
Sawdust bedding / dirty parlour wash | Acute mastitis - appears very similar to E.coli
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How does bacillus cereus and lichenoformis present?
Environmental from Brewers grains, dirty parlour wash | Acute mastitis
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How does pseudomonas present?
Sawdust / dirty parlour wash, poor hygiene when administering intra-mammary tubes Acute mastitis Difficult to treat
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How does mastitis caused by yeasts present?
Sporadic Wet mouldy bedding, teats washed before milking but not dried Poor hygiene
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How does summer mastitis present?
Dry cows and heifers outdoors in the summer | May also occur in housed cattle in the winter
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What are the causative agents of summer mastitis?
``` Truperella pyogenes Fusobacterium necrophorum Streptococcus uberis Bacteroides melaninogeneicus Peptococcus indolicus ``` Spread by hydrotea irritans
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How does summer mastitis typically present?
Hot, hard, very painful, swollen udder Thick purulent secretion Cow systemically ill May be lame Mild cases occur that are only noticed when the cow is calved down - Truperella pyogenes cultured
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How should you treat summer mastitis?
REMOVE ANIMAL FROM GROUP TO PREVENT SPREAD Cull - Poor response to antibiotics, forms abscesses in the quarter and irreparably damages the udder
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How can you prevent summer mastitis?
Fly control - SP tags in each ear, apply fly repellent to udder weekly Seal teats with tape House animals Move away from woodland Increase dry cow therapy to every 3 weeks
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What animals should you milk sample?
Bulk sampling Next 10 cows that have clinical case High SCC cows Cows that do not respond to treatment
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What is the cut off SCC when a farmer is no longer allowed to sell their milk?
Over 400,000 Most milk companies will not buy if over 200,000
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How can you assess whether there are repeat infections?
Ask the farmer to make a 2x2 grid Record quarter treated and date Can see whether there has been repeat infections
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What can a bactoscan tell you?
Coliform count - inadequate pre milking teat disinfection Thermoduric count - inadequate plant cleaning Physcotroph count - poor hygiene, refrigeration and contaminated bedding
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What does a high bactoscan result but a low SCC suggest?
Plant problem, not mastitis
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What antibiotics should you choose for a gram positive mastitis infection?
Beta lactams intra-mammary - penicillins, cephalosporins Macrolides systemic - Tylosin - for chronic S.aureus and Strep.uberis infections
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What intra-mammary antibiotic should you use for gram negative infections?
Aminoglycosides May not need to use anything - self resolves
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What intramammary antibiotic should you use for a mixed infection?
Trimethoprim potentiated sulphonamides
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What antibiotics are there no intra-mammary antibiotics for?
Fluoroquinolones Florfenicols Tetracyclines
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What antibiotics should you use in a hot, hard, udder where there is not culture and sensitivity results?
Broad spectrum antibiotics - you'll be in trouble with rob smith! TMPS Pen and gent - penicillin and aminoglycosides Cephalosporins
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What products are in the commercial Intra-mammary tubes?
Duo fast - TMPS (toxic mastitis) Tetra-delta - aminoglycosides (streptomycin, neomycin) + prednisolone Multi-ject - penicillin + aminoglycosides (streptomycin and neomycin) + prednisolone Synulox - potentiated amoxicillin - resistant S.aureus Ubrolexin - aminoglycoside (kanamycin) and cephalosporin (cephalexin)
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What causes a high SCC one month post-calving?
Gram negatives - E.coli, Klebsiella
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What causes a continuously fluctuating SCC?
S.aureus
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What causes a high SCC which responds well to treatment?
Strep agalactiae and strep dysgalactiae
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How can you tell whether mastitis has been cured or not?
SCC <100,000 twice, or <200,000 three times | California milk test
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When are bulk milk tank cell counts determined?
Every time the milk is collected
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When are individual cow cell counts determined?
Monthly
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What kind of cell count level will you see with E.coli mastitis?
400,000 - 800,000
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What kind of cell count will you see with S.aureus / strep.uberis mastitis?
>1,000,000 very high chronic cell counts
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How many days in milk should you consider drying a cow off early if they have clinical mastitis / high SCC?
Over 300 days in milk
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What are the 1st line intra-mammary tubes?
Multiject - penicillin + ag (streptomycin + neomycin) + pred UBRO yellow - penethamate (penicillin) + streptomycin + framomycin + pred Tetra-delta - penicillin + streptomycin + neomycin + pred Pathocef - cefoperazone Mastiplan - Cefapirin Ubrolexin - cefalexin
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What are you second line intra-mammary tubes?
Synulox - amoxicillin clavulanic acid Cobactan - cefquinome
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How long should a farmer leave between fore-milking and placing the cluster?
45-90 seconds
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When should change liners?
When there is signs of wear Squeaking sounds Every 2500 uses - every 90 days at Woodpark When cell counts are increasing
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What is the minimum number of services a milking machine should have?
Once a year
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How should you disinfect the cluster between high SCC cows and mastitic cows?
Rinse and spray with acetic acid
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What should you perform on a high SCC cow?
California milk test - shows what quarters are affected
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What should you give every case of mastitis?
Nsaid!!! Ketofen
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How does Truepurella pyogenes appear on culture?
Haemolytic colonies on blood agar | Gram +ve rod
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How does klebsiella appear on nutrient agar?
Large mucoid colonies | Gram -ve rod
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How does pseudomonas appear on nutrient agar?
Green pigmentation on nutrient agar | Gram negative rod