Mastitis Flashcards
(174 cards)
1
Q
what is mastitis?
A
inflammation of mammary gland
2
Q
what are the two categories of mastitis?
A
clinical
subclinical
3
Q
what is the difference between clinical and subclinical mastitis?
A
clinical - visible changes in udder, milk and cow
subclinical - no visible clinical signs but changes to SCC, milk quality and yield
4
Q
what are the type of clinical mastitis?
A
grade 1, 2A, 2C and 3
5
Q
what is grade 1 mastitis?
A
mild mastitis with changes to milk (consistency, clots…)
6
Q
what is grade 2A/C mastitis?
A
acute/chronic mastitis with changes to milk and udder ranges from hot and painful to hard and lumpy
7
Q
what is grade 3 mastitis?
A
changes in milk and udder and cow is sick
8
Q
what are the main environmental pathogens of mastitis?
A
E. coli
Strep uberis
Klebsiella spp.
9
Q
what are the main contagious pathogens of mastitis?
A
Strep uberis
Strep agalactiae
Strep dysgalactiae
Staph aureus
Coagulase negative staphs
Mycoplasma spp.
10
Q
what pathogen is both an environmental and contagious mastitis pathogen?
A
Strep uberis
11
Q
what are the possible consequences of a cow not clearing a mastitis infection?
A
chronic infection causing spread to the herd
permanent udder damage (milk drop…)
death (toxaemia or cull)
12
Q
are most contagious mastitis pathogens gram positive or negative?
A
positive
13
Q
how does high somatic cell count effect the milk product?
A
high SCC milk goes off faster (due to the effect on the fat breakdown)
14
Q
what is the legal limit for SCC?
A
repeatedly over 400 000 (want to be under 200 000 - financial penalties at this point)
15
Q
what are the two defence systems of the mammary gland?
A
innate immune system (first line defence)
acquired immune system
16
Q
what does the innate immune system of the mammary gland consist of?
A
resident leucocyte
antimicrobial substances in milk
teat canal
teak skin
17
Q
how does the teat skin work as part of the innate immune system?
A
prevents colonisations of the teat with bacteria by its stratified squamous epithelium with bacteriostatic fatty acids
18
Q
what can compromise the innate immune function of the teat skin?
A
chapping, bruising, trauma, teat lesions caused by the milking machine and calves…
19
Q
what features of the teat canal help too protect against pathogens?
A
keratin lining traps bacteria and continuously sloughs
keratin plug seals off teat end when cow is dried off
20
Q
how long does the teat sphincter muscle take to close after milking?
A
20-30 minutes
21
Q
what are the grades of teat end hyperkeratosis?
A
no ring
smooth/slightly roughened ring
rough/very rough ring (increased mastitis)
22
Q
what increased the risk of teat end hyperkeratosis?
A
excessive milking vacuums
faulty pulsations
liner type
teat shape
23
Q
how can we protect the teat end/canal?
A
genetics (good conformation)
milking machine function
loafing time post milking (lameness??)
teat sealants/drying off
24
Q
what factors inside the udder contribute to the innate immune system?
A
resident leucocytes
lactoperoxidase
lysozymes
lactoferrin
complement
25
what are the main resident leucocytes if the udder?
macrophages, neutrophils and T lymphocytes
26
what are the functions of the resident leucocytes of the udder?
phagocytosis and killing of pathogens
trigger acquired immune system (antigen presentation and pro-inflammatory mediators)
27
what produces lactoferrin in the udder?
epithelial cells and leucocytes
28
when is lactoferrin levels in the udder highest?
during the dry period (inhibit bacterial growth)
29
is lactoperoxidase bacteriostatic or bactericidal?
bacteriostatic
30
are lysozymes bacteriostatic or bactericidal?
bactericidal
31
what does the initial response of B lymphocytes in the udder produce?
IgM and IgG1
32
what does repeated exposure of B lymphocytes to pathogens on the udder cause production of?
IgG2
33
what are the two types of T lymphocytes involved in the acquired immune response of the udder?
T helper cell
T cytotoxic cells
34
what is the role of T cytotoxic cells in the udder?
eliminate host cells invaded by pathogens
35
what is the function of IgA in the acquired immune response in the udder?
agglutination of bacteria and neutralisation of toxins
36
what factors effect the mammary gland immunity?
genetics
stage of lactation
nutrition
vaccination
stress
37
what genetic traits effect the resistance to mastitis?
udder type, speed of milking, yield, neutrophil function
depends of breeds (even variation within breeds)
38
what genetic factors are we currently able to select for to increase mastitis resistance in cows?
low SCC (don't want too low)
udder confirmation
yield
39
what are the high risk periods of lactation for mastitis infection?
early/late dry period and early lactation (these are times when immunity is lowest and the udder isn't being cleared out)
40
when is the best time to clear the udder of mastitis infection?
middle of dry period down udder as involuted
41
why is the early and late dry period a risk factor for mastitis?
milk/colostrum production occurring - leakage and good growth medium
42
what factors of the dry period could predispose to mastitis?
cessation of milking - increased intramammary pressure and teat canal widening
no clearance of bacteria
no teat dipping
keratin plug takes time to form
43
why is neutrophil function decreased in the early dry period?
secretions have high fat and cell debris content which impairs the function
44
why is white blood cell function reduced in the udder of periparturient cows?
increased colostrogenesis interferes with neutrophil capacity
stress and hormone levels (cortisol is immunosuppressive)
45
how does nutrition effect mastitis?
negative energy balance - lower WBC count
SARA - poor hygiene and negative energy balance
hypocalcaemia - weakened teat sphincter
46
what mastitis pathogens is there a vaccine for?
Staph aureus, coliforms and coagulase negative staph
Strep uberis
47
what is the issue with the vaccine for mastitis pathogens?
must be given 3 or 4 times per lactation
48
how often do teat liners need replacing?
ever 2500 milkings or 6 months
49
if milk is unable to leave one of the claws during milking, what is the most likely cause of this?
problems with the air bleed
50
what is the pressure of the vacuum applied during milking?
42-48 kpa
51
what generates a non-continuous vacuum in the milking parlour?
pulsator (allows teat to rest and circulation to be restored)
52
how can mastitis infection be passed by the actual milking machine?
liner contamination
wet milking - milk flushed upwards due to inadequate vacuum or blocked air bleeds
53
what can cause a fluctuating/inadequate vacuum of the milking machine?
inadequate pump/reserve
holes in tubing
cluster falling off of slipping
54
what is teat end impact?
milk flowing back up to the teat end due to a blocked air bleed
55
if the pulsator is set too fast, what happens?
the teats don't get enough rest - swollen blue teats causing damage to skin and teat end
56
what are some simple things that can be assessed on a milking machine?
blocked air bleeds
cleanliness of liners
wear of liners
perished/holed tubing
vacuum gauge (42-48kpa)
57
how often should a parlour be serviced?
every year
58
what are the positive of fore milking?
stimulate milk let down
early mastitis detection
(legal requirement)
59
what are common disinfectants used for pre-dipping in the parlour?
chlorohexidine
iodophors
chlorine dioxide
hypochlorite
60
what are some considerations for pre-dipping in the parlour?
correct concentration
correct contact time
correct coverage
61
what is the milk ejection reflex?
teat stimulation causes neural input to the hypothalamus which triggers oxytocin to be released from the posterior pituitary leading to myoepithelial cell contraction in the mammary gland
62
how long should be the time between wiping and putting the cluster on?
30-45 seconds
63
what are the possible constituents of a teat dip?
emollients
dye
disinfectant - iodine, chlorhexidine, lactic acid, ammonium compounds
64
what are the advantages/disadvantages of loafing time?
allows closure of sphincter to prevent environmental infection
but can exacerbate lameness
65
what is the ideal milking order?
(milk least likely to be infected/most susceptible first)
heifers
fresh calvers
high yielders
low yielders
high cell count
mastitis
66
how are high cell count or mastitic cows managed in the parlour?
mark them
use a separate cluster and disinfect/backflush
(hypochlorite or peracetic acid)
67
if a farm is having an issue wit Staph aureus mastitis, what should be done in the parlour wash routine?
should be a hot wash every milking
68
what are some infectious causes of teat damage?
warts - papilloma
pdeudo-cowpox
bovine herpes mammilitis
black spot
cowpox
udder impetigo
69
what are some non-infectious causes of teat damage?
hyperkeratosis
photosensitisation
chapped teats
cut teats
teat peas
teat stenosis
blind teats
70
what is an issue with warts on the teat end?
good place for bacteria to harbour
irregular shape means that disinfectant doesn't get to all the skin
distort teat sphincter - bacteria get in
71
what is the issue with using teat cannulas?
holds the sphincter/canal open - mastitis is extremely common
72
what is the general treatment for teat disorders?
teat cannula
antibiotics
emollients
antiseptic
(milking order??)
73
what age animal is bovine papillomatosis seen in?
young animals
74
what are the issue with teat warts?
harbour bacteria (mastitis)
poor liner attachment
pain (calf sucking/milking)
75
how are teat warts treated?
many self resolve
removal (surgery, league, cryosurgery)
autogenous vaccine
(fly control)
76
what pathogen causes pseudocowpox?
parapox virus
77
what shape are the lesions of pseudocowpox?
horse shoe/circular
78
what is done to treat pseudocowpox?
post milking teat dipping (emollient and disinfectant)
79
what pathogen causes bovine herpes mammilitis?
bovine herpes virus 2
80
do cows develop immunity to bovine herpes mammilitis?
yes (lifelong)
81
what is the main source of cowpox transmission?
cats (not seen in UK for years)
82
what is black spot?
damage to the teat end (milking machine...) plus a secondary infection of Fusobacterium necrophorum
83
how is black spot treated?
antibiotics and cannula
check milking machine
84
what is usually the pathogen that causes udder/teat impetigo?
Staph aureus
85
what type of lesions are seen with udder/teat impetigo?
pustular
86
is it less painful to milk a chapped teat by hand or by machine?
by machine is usually tolerated better
87
what are the three roles of teat dip?
pre-milking - remove environmental pathogens from teat skin
post-milking - kill bacteria after milking and protect from new infections
condition teat skin
88
what possible disinfectants can be used in teat dips?
iodine
chlorhexidine
lactic acid
chlorine dioxide
ammonium compounds
89
what are teat peas?
pedunculate granuloma attached to the wall of the teat canal (blocks milk flow)
90
how are teat peas treated?
hudsons spiral inserted up teat canal and jerk to tear the granuloma off
mosquito forceps to tear the granuloma off
can do surgery
(needs prophylactic antibiotics to prevent mastitis)
91
how is teat stenosis treated?
local anaesthetic and insert small teat knife then rotate
92
what is the prognosis for treating teat stenos?
guarded as scar tissue often forms which causes stenosis
93
if a teat is cut all the way through to the canal how is it treated?
insert cannula and then suture closed
94
what are the five freedoms?
freedom from hunger/thirst
freedom from discomfort
freedom from pain/injury/disease
freedom for normal behaviour
freedom from fear/distress
95
roughly how much lunging room does a cow need?
1m
96
what is the minimum feed space needed or a dry cow?
1m
97
what shape should a loose straw yard be?
rectangular (cows like to lie along the edge and don't want them walking too far to get to feed/water)
98
what is the cow comfort quotient?
number of cows correctly using a cubicle divided by number of cows interacting with any cubicle (want as high as possible)
99
what can be used to prove poor cubicle design/use to a farmer?
disease - lameness, mastitis, lesions
behaviour of cows
adjust some to see how interaction changes
100
what does a cow who has reversed into a cubicle indicate about the cubicle?
the curb is too high as they dislike backing down it
could indicate bullying issue as well
101
what could back lesions indicate about a farms cubicles?
the lower rail height isn't correct as it is rubbing when they are lying down
102
what is the issue with using sand for bedding?
damaging to slurry system and settles in tower (takes a lot of management)
103
what is green bedding?
recycled manure solids (only allowed in cubicles in UK)
104
how many hours of light to cows need to maximise feed intake and milk production?
16-18 hours
105
what in parlour monitoring can be done for mastitis?
fore milking
clinical signs
inline filters
California milk test
106
what are the ways of monitoring/investigating mastitis on a farm?
in parlour monitoring
clinical case records
SCC
bulk milk bactoscan
bacteriology
multiplex PCR
107
what is the California mastitis test?
detergent that breaks down cells in the sample which then releases DNA which turn gelatinous
108
how does mastitis change the electrical conductivity of milk?
mastitis increases the electrical conductivity due to there being more chloride (this can be monitored on an individual cow basis)
109
what can causes photosensitisation? (can be seen on udder)
plant ingestion
mycotoxicosis
liver disease
110
what is the target for number of mastitis cases per 100 cows per year?
<30
111
what does a high bulk tank SCC suggest about mastitis?
high number of chronically infected animals with mastitis
112
what are the three main milk recording companies in the UK?
NMR (national milk recording)
CIS (cattle information service)
QMMS - quality milk management service
113
what does a SCC of 100 000 to 200 000 cell/ml suggest about a cow?
likely to have a quarter infected with a minor mastitis pathogen
114
what does a high SCC at the start of lactation suggest will happen?
develop a clinical mastitis case in that lactation (very good predictor)
115
why are cows that have been chronically infected with mastitis for a long time less likely to be cured that those who are only recently chronic?
abscesses forma and lymph nodes become more chronically infected the longer disease is present
116
what is the quickest way to fix a high bulk tank SCC?
take cows contributing the highest SCC out of the tank
117
roughly what SCC will show as positive on a California mastitis test?
>300 000 cells/ml
118
what is a bactoscan?
actual count of bacterial numbers in milk (growing on milking plant, in mastitis udders and on dirty udders/teats)
119
how often if a bactoscan typically done?
weekly (can get daily)
120
what are some possible causes of a raised bactoscan?
poor housing hygiene
poor pre-milking teat preparation
high levels of mastitis
poor plant cleaning
121
what bacteria can be assessed to determine plant cleanliness?
LPC thermoduric and pseudomonas
122
what bacteria can be assessed on a bactoscan to determine environmental contamination and pre-milking teat preparation?
coliforms
123
what specific figures can be assessed from bulk milk tank bacteriology?
total bacterial count
cell count
LPC thermoduric count and pseudomonas
coliform count
total Staphylococcal count
Staph aureus
124
what does getting three major pathogens in your milk sample suggest?
probably contaminated the sample
125
what is the five point plan for mastitis?
post-milking teat disinfection
dry cow therapy
prompt treatment of clinical cases
cull chronic cases
maintain/use milking machine properly
126
should gram positive or negative mastitis pathogens be treated rapidly?
gram positive (negative may be alright without antimicrobials)
127
is the five point plan better for contagious or environmental pathogens?
contagious
128
do mastitis cases self cure?
depends on the bacteria
129
what mastitis cases are farmers advised to leave to self cure?
mild gram negative cases (as long as they don't become toxaemic)
130
how effective is udder mint on mastitis cases?
has little effect
131
how effective is oxytocin on mastitis cases?
reduces the bacterial count (let more immune cells into udder and better milk clearance)
132
how long is the traditional dry period?
60 days (not below 40)
133
what is different between normal dry cow tubes and xtra dry cow tubes?
can't tell - have to look on the box
134
why is dry cow therapy used?
clear persistent infection
protect against new infections (dry cows, after calving...)
135
why does treating Staph aureus mastitis require long exposure to antimicrobials?
Staph aureus is intracellular so it needs time to diffuse into the cell
136
what are some pathogens associated with summer mastitis?
Arcanobacter pyogenes
Peptococcus indolicus
Strep dysgalactia
137
what are the disadvantages of dry cow therapy?
getting a SCC too low (increase infection)
new infections from poor hygiene during application
resistance to drugs
cost
138
what is the majority of Staph aureus mastitis resistant to?
penicillin
139
what is selective dry cow therapy?
teat sealant only some cows (can be used in combination with antibiotic tubes)
140
what are the three sealant products?
orbeseal
boviseal
ubroseal blue (has a dye)
141
how long can teat sealant stay in the teat cistern?
up to 100 days
142
is mastitis more/less common when using a dry cow sealant?
less common when sealant is used
143
how can cows be selected for dry cow therapy?
bacteriology
SCC (200 000cell/ml ml cut off)
clinical mastitis cases
california mastitis test
check teat end for damage
144
why is it difficult to diagnose Staph mastitis using bacteriology?
it is intermittently shed so may not be present in the sample
145
what is a major issues with sealant use in dairy cows?
the bismuth subnitrate in it reacts with the hydrogen sulphide from maturing cheese to cause black spots
if not done a sterile condition there is a risk of infection
146
what is the advice for farmers when starting to using sealants?
only use of some of the cows to begin with then increase - ensures the correct application before giving it to the rest of the herd
147
how is different durations of actions of dry cow tubes created?
type of antibiotic
salt of antibiotic
particle size
base - oil, emulsions...
148
what is the primary target of dry cow tubes?
Staphylococcus (then broaden out)
149
what antibiotic used in dry cow tubes target Staphylococcal infections?
cloxacillin or penicillin
150
what antibiotic is used for broad spectrum antimicrobial treatment in dry cow tubes?
ampicillin
151
what are the main antibiotics dry cow tubes are based around?
cloxacillin
penicillin
cephalosporins
152
what is used in penicillin dry cow tubes that has gram negative effects?
framycetin
153
what is the function of penethamate in penicillin based dry cow tubes?
gets intracellularly to kill intracellular pathogens (Strep uberis or Staph aureus)
154
what is required to use CIA (cefquinome) dry cow tubes?
culture and sensitivity on high cell count cows at the end of lactation and start of the next lactation
155
what is the rough milk withhold for dry cow tubes?
96 hours (can be influenced by milking frequency and milk fever)
156
if a cow with a dry cow tube aborts/calves early what is done with the milk?
disposed off - farmer tests until no antibiotics are present in it
157
other than dry cow tubes what treatment can be given at drying off?
tylosin
tilmicosin (Staph aureus)
long acting macrolides
(efficacy for these isn't very good and difficulty with licensing)
158
what is the issue with using long acting macrolides meant for pneumonia as dry cow therapy?
aren't licensed for lactating animals and very little proven efficacy
159
how can you monitor for successful dry cow therapy?
look at SCC at the start of lactation to see if it has increased, decreased or stayed the same
160
why may there be a mastitis treatment failure?
incorrect treatment protocol
antibiotic resistance
bacterial dormancy (antibiotic goes away pathogens come back)
L-forms
biofilm (resistance)
reduced host response (steroids, stress...)
reduced phagocytosis due to antibiotics
reinfection
pharmacokinetic limitations
161
what are L-forms of bacteria?
bacteria that don't have a cell wall in part of their growth phase meaning they are insensitive to beta-lactams
162
what antimicrobial is able to suppress L-form formation?
novobiocin
163
what are some possible sources of mastitis reinfections leading to treatment failure?
another quarter
teat canal infections from nozzle
external sources
164
why might antibiotics not reach the site of infection in adequate concentrations?
too low of a dose
too long of a dose interval
too short treatment period
165
what are some possible pharmacolimitations that cause mastitis treatment failures?
sequestration due to ionisation
diffusion barriers in intramammary treatment
poor delivery across blood/milk barrier
antibiotic binding to milk or serum protein
if the pathogen is intracellular
166
are fluoroquinolone required for E. coli mastitis?
no - trend to do fine with just ketoprofen
167
what antibiotics are best to start treating Klebsiella and Pseudomonas mastitis with?
sulphonamides
168
what are the worst antibiotics to use for Strep dysgalactiae mastitis?
tetracyclines systemically
169
what is the main advantage of treating mastitis aggressively for a long period of time?
less likely to get chronic cases
170
what systemic antimicrobials gets into udder tissue well?
macrolides
phenicol
tetracycline IV
fluoroquinolones
trimethoprim
171
other than antimicrobials what else can be considered to treat mastitis?
oxytocin
vitamin E
zinc (teat keratin)
vaccine
pain relief
172
what mastitis pathogens is there a vaccine against?
E. coli
Strep uberis
173
what are the advantages of pain relief in mastitis cases?
less likely to be kicked in parlour
NSAIDs are anti-endotoxic
eat more, milk more, recover better
174
what should be done before treating every mastitis case?
sample and freeze - can culture if treatment is effective
