10 + 11: Mastitis Flashcards
1
Q
What is the usual cause of mastitis?
A
Bacteria
2
Q
What does subclinical mastitis present as?
A
No changes to milk, see as somatic cell count
3
Q
Which kind of mastitis cases can cause significant hyperalgesia?
A
Even mild cases
4
Q
What is the most common cause of death in adult cattle?
A
Clinical mastitis
5
Q
What four factors can mastitis adversely affect?
A
Fertility, milk yield, milk quality, somatic cell count
6
Q
Through which stages can mastitis cycle?
A
Clinical to subclinical to chronic
7
Q
Why can contagious mastitis be controlled?
A
Because transmission is linked to the milking process so there is a reservoir of infection
8
Q
Which kind of mastitis is impossible to eradicate?
A
Environmental
9
Q
What is the most common mastitis bacteria?
A
Strep uberis
10
Q
How long does E Coli mastitis tend to last?
A
Transient
11
Q
What does Strep agalactiae mastitis usually present as?
A
Subclinical
12
Q
Which bacteria produce the most persistent infection?
A
Gram +ves
13
Q
Which kind of mastitis is the 5-point control plan good for?
A
Contagious
14
Q
What is the 5 point control plan?
A
Machine maintenance, teat disinfection post-milking, antibiotic dry cow therapy, prompt treatment and recording, culling if chronic or recurrent
15
Q
What are clinical signs of systemic mastitis?
A
Fever, anorexia, toxaemia
16
Q
Why is it useful to grade mastitis severity?
A
To find the causative agents and select a therapy
17
Q
What is grade 1 mastitis?
A
Changes to secretion only
18
Q
What is grade 2 mastitis?
A
Changes to secretion and udder
19
Q
What is grade 3 mastitis?
A
Systemically ill cow
20
Q
Which bacteria especially causes grade 3 mastitis?
A
Coliform
21
Q
How do you culture your milk samples?
A
24 hour culture on blood agar
22
Q
What are 5 ways of detecting subclinical mastitis?
A
Increased somatic cell count, sterile milk culture, electrical conductivity, lactate dehydrogenase, NAGase
23
Q
Which cells make up the somatic cell count?
A
Epithelial and white blood cells
24
Q
What is somatic cell count a measure of?
A
Udder stress, damage or irritation
25
Over what somatic cell count shows infection?
200,000
26
What is the legal EC somatic cell count limit?
400,000 per ml
27
What other factors affect somatic cell count?
Age, stage of lactation, season, stress, breed
28
How do you avoid seasonality in somatic cell count penalties?
13 weeks geometric mean
29
Which cells show infection in milk
Neutrophils
30
Which cells are in healthy milk?
Mainly macrophage
31
What % of UK cows have individual somatic cell levels measured?
50%
32
Which quarters are measured for somatic cell counts?
Composite of all quarters
33
What is the usual somatic cell count cutoff in the UK?
200,000/ml
34
How does a CMT work?
Detergent with indicator to break down cell membranes so becomes gelatinous and acid release causes colour change
35
What do bactoscans measure?
Bacteria in bulk milk
36
Which levels determine milk quality payments?
Bactoscans milk levels
37
What does optimal milk let down require?
Oxytocin and pre-stimulation
38
How does stress affect oxytocin release?
Inhibits
39
What is an advantage of massaging teats while wiping?
Stimulates oxytocin release and causes milk ejection
40
How soon after disinfection should you apply to machine?
90 seconds
41
How can you measure teat cleanliness?
From 1-4, or swab for bacteria
42
How quickly will most cows milk out?
5-7 minutes
43
How can you avoid teat damage when taking off the milking machine?
Turn off the vacuum first
44
How long do the streak canals stay open after milking?
1 hour
45
How can you keep cows standing for 1 hour after milking?
Give food
46
What must you make sure if using a spray to disinfect?
Must ensure full coverage
47
What's a problem with cracked teat liners?
Allows milk to remain
48
What are signs of damage to the teat from the milking machine?
Red teats, swollen, orifice remains open, hard, cyanotic
49
What are medium term changes from teat damage?
Petechiae or larger haemorrhage
50
What does hyperkeratosis of the teat end show?
Long-term change from slow or over-milking
51
Above what % of cows showing hyperkeratosis is a problem?
10%
52
How can you measure therapy success?
Clinical or bacteriological cure
53
What are the three therapeutic targets of treatment?
The cow if systemic, the parenchyma of the mammary tissue, the milk, lining, ducts and alveoli of the mammary gland
54
What's an advantage of intramammary antibiotics?
Allow effective concentration to be attained in milk
55
Which pathogens are intramammary antibiotics useful for?
Non-invasive like S agalactiae, coagulase -ve Staph, S dysgalactiae
56
How many milkings do you use intramammary antibiotics for?
Three
57
Which kind of cure is less likely with intramammary antibiotics?
Bacteriological e.g. S uberis and S aureus
58
What kind of infection can still be present after intramammary antibiotics?
Subclinical
59
Is milk saleable after intramammary antibiotics?
yes
60
What is a problem with intramammary antibiotics?
Causes more chronic infections, fibrin and micro-abscesses, 24-36 hour limit for infectiveness
61
Which kind of antibiotics can you use if deep tissues are involved (grade 2)?
Parenteral
62
When are parenteral antibiotics indicated?
Where pathogens are invasive and create absceses (S aureus and S uberis)
63
What are some examples of parenteral antibiotics used?
Erythromycin, potentiated sulphonamides
64
How do you treat grade 1 mastitis?
Standard intra-mammary infusion
65
How do you treat grade 2 mastitis?
Intramammary infusion and parenteral antibiotics
66
How do you treat grade 3 mastitis?
Consult vet
67
What do you do if you have not achieved a clinical cure after repeated cases?
Treat for 2-3x longer than normal, give parenteral antibiotics, change tubes
68
When is drying off the whole cow an option?
80 days after calving
69
Which is udder mint useful?
Increases blood supply
70
What are some adjunct therapies you can try?
Steroids, NSAIDs, oxytocin
71
What does therapy for severe mastitis target?
Coliform mastitis, treats the bacteraemia not the gland
72
When do you do extended intramammary therapy?
Gram +ves
73
How do you treat endotoxic shock?
Hypertonic saline, NSAIDs, calcium
74
What dose of hypertonic saline do you use?
3l per 600kg
75
Before drying off, what do you reduce yield to?
15L
76
How do you dry off?
Abruptly, give antibiotics, teat sealant and dry cow diet
77
How much higher is dry period susceptibility than during lactation?
10x
78
Why is dry period susceptibiltyi higher?
No flushing of bacteria, increased intramammary pressure, stopping of teat disinfection
79
What is resistance to infection like when quiescent?
Resistant
80
What is resistance like during colostrogenesis?
Increased pressure again
81
Which kind of antibiotics may chronically S aureus infected cows need?
Parenteral
82
How do you ensure a cow is not infected at drying off?
Using somatic cell count but not if giving antibiotic tubes
83
What are the two types of teat sealant?
Internal or external
84
What do you do to cows with persistent high somatic cell counts?
Segregate
85
What do you do to cows that don't respond to antibiotics or are persistently infected?
Cull
86
Why do teat lesions make the udder more susceptible to intra-mammary infection?
Can be colonised by mastitis bacteria
87
What kind of virus causes cowpox?
Orthopoxvirus
88
How common is cowpox?
very rare
89
What are clinical signs of cowpox?
May be mildly febrile
90
How do you treat cowpox?
Usually heals within one month
91
What kind of virus causes pseudocowpox?
Parapoxvirus
92
How common is pseudocowpox?
More common and milder
93
What do lesions look like in pseudocowpox?
Horseshoe-shaped
94
Why is reinfection with pseudocowpox common?
Little immunity
95
What does pseudocowpox cause in humans?
Milkers nodule
96
Which virus causes Bovine Herpes Mammilitis?
BHV-2
97
What do BHV-2 lesions look like?
raw and ulcerated and very painful
98
How do you treat BHV-2?
Emollients and aciclovir
99
Which viruses cause warts?
BPV-1,5,6
100
What kind of warts can occur on teats caused by BPV?
Papillomas and fibropapillomas
101
How is BPV spread?
Direct and indirect contact
102
What problems can warts cause?
Can interfere with milking
103
How do you treat warts?
Surgical excision
104
What kind of prevention is available for warts?
Autogenous vaccine
105
What bacteria causes Black Spot?
Fusobacterium necrophorum
106
What initaited black spot?
Damage to teat orifice from the milking machine
107
What is milking like during black spot infection?
Incomplete and slow
108
What bacteria causes udder impetigo?
Staph spp
109
What does udder impetigo look like?
Pustules of udder and teats
110
How do you treat udder impetigo?
treat by antiseptic skin until resolution
111
What causes udder cleft dermatitis?
Treponemes
112
What are clinical signs of summer mastitis?
Inflamed swollen teats, purulent and foul smelling secretion, secretory function lost, joints swollen, toxaemia, abortion, death
113
What bacteria causes summer mastitis?
Trueperella pyogenes, also others
114
How does summer mastitis spread?
headfly so occurence relates to fly habitat
115
What are risk factors for summer mastitis?
No dry cow therapy, flies, autumn calving, teat damage, age
116
Which training helps farmers avoid antibiotics in milk?
Milksure
117
Which bacteria can you vaccinate against?
S aureus and coliforms
118
How does coliform vaccine affect severity and incidence?
Reduces severity but not incidence
119
What are some clinical mastitis parameters?
% herd affected, case rate, new infection rate, case:cow ratio, repeat case rate, chronic rate, antibiotic tube usage
120
How can bull choice affect mastitis?
Somatic cell count in bull proofs
