Mastitis 1

Question 1

a cow is at risk of developing mastitis the most during what 2 periods?

Answer 1

just after the dry off period

just before calving

Question 2

list 5 characteristics of active invulution of the udder

Answer 2

• milk is still being secreted but slows down, and pressure builds in the udder
• there is a possible change in the permeability of blood mill barrier due to autophagocytosis of secretoty epithelial cells
• the concentrations of serum and milk components change, for example some cows increase in albumin and IgGs during this time
• there is an increase in lactoferrin which is an immunomodulator
• milk leaks sometimes and there’s no decomtamination of the teats during this time

Question 3

list 4 things that happen during lacto/colostrogenesis

Answer 3

• cells are acgively differentiating
• there is an increase in pressure from secretion, and lactoferrin decreases as well as leukocytes decrease
• phagocytes dont work as well and are impaired by colostrum components
  -dry cow therapies like intramammary antibiotics are not at MIC during this time

Question 4

many intramammary infections are acquired during _____ and what is the result of this?

Answer 4

the dry period, so they show up as cases of mastitis within the first 90 days after calving and this has huge impacts for the productivity of the cow

Question 5

main 2 reasons why cows get mastitis?

Answer 5

failure of host immunity AND/OR overhwleming exposure

Question 6

describe what the innate immunity of the udder is like

Answer 6

it is non specific, it’s always there, and is activated quickly. it is not made any better with repeated exposure, and mostly involves the physical barrier of the teat end and involves macrophages, neutrophils, NK cells, and soluble factors

Question 7

the teat canal is liend with keratin, what does this do?

Answer 7

it is waxy, has antimicrobial properties, and provides a physical barrier to bacterial migration into the teat

Question 8

somatic cells in the normal udder are made up of what? what about when there is an infection

Answer 8

macrophages»neutrophils, lymphocytes, epithelial cells

during infection: mostly neutrophils

Question 9

true or false: it is harder for immune cells to do their job in the milk compared to the blood

Answer 9

true

Question 10

what impairs the immune defenses on the teat/

Answer 10

damage to the teat end, or immune suppression (nutrition deficinecy, other diseases, genetics, hormones, stress)

Question 11

teat end hyperkeratosis is caused by what

Answer 11

chronic stimuli such as over milking, or equipment settings like the vacuum or pulsation system, or it could be a problem with the cows teat shape or position

Question 12

should you normally see a ring around the teat canal?

Answer 12

NO

Question 13

why is hyperkeratosis of the teat a problem? who even cares bestie?

Answer 13

it predisposes to bacterial colonization! oh no! a score of 3 or 4 increases risk of both contagious and environmental mastitis

Question 14

a cow named JESSIE needs her teats assessed. how you gonna do that bestie?

Answer 14

use a flashlight and get under there to look! you can also use a teat scorer app on an ipad, make sure to wear gloves so you can palpate if you can’t see very well

Question 15

you look under JESSIE to see her honkers and you see a black spot on the end of her teat. You also notice her two friends beside her have the same lesions too! what are you thinking this is? how did JESSIE get this?

Answer 15

a necrotic area at the teat orifice that has a secondary infection, usually staph species

she got this probably from poor milking conditions–>high teat end vacuum, impaired pulsation. Fix the underlying issue and you wont have it happen anymore!

Question 16

cows can get infectious teat lesions casued by herpes. what specific virus causes this? what do lesions look like and how should you deal with this if you see it?

Answer 16

bovine herpesvirus 4

starts as vesicles that then rupture and leave ulcers, thick dark red scabs form, painful swelling

milk these cows last and disinfect clusters, can also use emollient cream to speed healing

Question 17

psuedocowpox can also cause lesions on the teats. what do these lesions look like?

Answer 17

they’re circular and red and can also be in the mouth. typical pox lesions. this takes a while to go away

Question 18

what are some common bedding materials for lactating cows? what about dry cows and heifers?

Answer 18

straw, shavings, manure solids, compost pack, sand

can be in stalls but are usually outside with straw packed bedding

Question 19

what kind of bedding has the least risks?

Answer 19

dry and inorganic bedding has lower bacterial counts which is good!!

sand is the best, then organics like straw and shavings, then recycled manure (duh)

Question 20

what is the acceptable number for colony forming unit per ml for bedding?

Answer 20

fresh bedding should be less than 5000cfu/ml and bedding should always be less than 1 million cfu/ml

Question 21

true or false: all bedding is bad after a certain amount of time

Answer 21

true! E coli and klebsiella will be high in old bedding regardless of type!

Question 22

you’ve been asked to go check out a dairy farm and evaluate the cow’s udders for cleanliness. how will you do this?

Answer 22

1=no maure or dirt
2=2-10% of udder has dirt or manure
3=10-30% has dirt or manure
4= more than 30% has dirt or manure

Question 23

you go out to a dairy farm and the girl’s all have high udder hygiene scores (many 3s and 4s). You educate the producer about this but he isn’t convinced. What do you tell him? hint: use a cool stat you awesome nerd

Answer 23

cows with udder hygiene scores of 3 and 4 are 1.5 times more likely to have major pathogens isolated from milk samples compared with cows who’s scores were 1 or 2

Question 24

true or false: the milking machine is responsible for many mastitis cases on farm

Answer 24

false! usually not an issue in most cases

Question 25

what is the most important “setting” on the milking machine and why?

Answer 25

the teat end vacuum! It needs to be in a narrow range, must remain stable, and can’t be too high!

Question 26

why is the milking procedure an important factor in mastitis management?

Answer 26

the timing of milk let down MUST be coordinated with application of the milking cluster, it is also a time to examine the udder

Question 27

milk let down is most effective when you

Answer 27

idk gotta get notes from someone

Question 28

______ is a major control point for prevention of new infections

Answer 28

pre and post milking teat disinfection

Question 29

within how many seconds from fore stripping to attaching the milking unit should there be?

Answer 29

60 seconds (more than 90 is delayed and more than 120 is late attachment)

Question 30

why do we fore strip and what is the proper way to do it?

Answer 30

it is the best ay to provide stimulation for milk let down
you want to fore strip for 10-15 seconds which is about 3 strips per quarter
this is also a nice time to check the milk and udder for signs of mastitis
also the milk just sitting in the cistern has high SCC so we can get rid of that and lower the SCC in the bulk tank

Question 31

what can happen if you dont allow time for the cow to let down her milk?

Answer 31

it exposes the teat to high vacuum levels which is uncomfy and can lead to teat hyperkeratosis. AND less milk is usually harvested

Question 32

what is the proper way to do pre dipping?

Answer 32

dip the entire teat and barrel, should apply to a clean teat NOT a dirty one, you need good contact time

Question 33

why is it important to control environmental mastitis pathogens in particular?

Answer 33

because this is what is on the end of the teat right when milking starts, so the pathogens can get into the teat canal when you put the machine on the cow

Question 34

proper way to wipe pre dip off?

Answer 34

after contact time it needs to be wiped off, and the bottom of the teat MUST be wiped not just the barrel! What you wipe with has an impact: use clean single use towels, cloths, or paper towels. OR can use reusable IF it’s been washed and disinfected

Question 35

what is the single most important step of the milking routine to prevent new udder infections?

Answer 35

POST DIPPING

Question 36

should post dips get wiped off?

Answer 36

NOOOOOOOOOO

Question 37

why is post dipping so important for controlling contagious mastitis pathogens?

Answer 37

there is milk film on the teats after milking which could be from all quarters, a single quarter, just that one cow, or multiple cows

Question 38

what is post-prep teat end swabbing?

Answer 38

you swab the teat with alcohol after the pre dip is wiped off to assess the cleanliness of the teat end. use one corner of a piece of gauze for each teat

Question 39

list the contagious udder pathogens

Answer 39

staph aureus
staph agalactiae
mycoplasma bovis

spread from cow to cow during milking procedure

Question 40

list the environmental udder pathogens

Answer 40

E coli
klebsiella
strep uberus

reservoir in the environment, not spread from cow to cow

Question 41

there is one pathogen that is opportunistic and commonly affects milking heifers. what is it?

Answer 41

non aureus straph (NAS)–>staph chromogenes usually

it colonizes the skin on the teat and then gets into the udder

Question 42

true or false: a heifer cow can get infected with NAS before she calves

Answer 42

true! then she will most likely have subclinical, but could be clinical too

Question 43

list examples of pathogens that are initially acquired in the environment, but then spread from cow to cow once there are enough cows affected

Answer 43

strep uberus
prototheca (an algae)

Question 44

characteristics of E coli mastitis

Answer 44

acute infection, release of endotoxins, septicemia/bacteremia, systemic infection

large swollen quarter with watery milk]

these cows need systemic therapy

systemic antimicrobials, NSAIDs, fluids

Question 46

characteristics of klebsiella pneumoniae mastitis

Answer 46

can look like E coli, but sometimes not as severe systemically. 1/3 mild, 1/3 moderate, 1/3 severe.

Healthy cows shed klebsiella in manure

invades deep into udder tissue–>infections can become chronic/subclinical

treatment is the same as E coli

Question 46

characteristics of streptococcus uberus mastitis

Answer 46

risk factors: straw, dirty tails, manure on hind teats

shed in feces

typically moderate mastitis, and then 4-6 weeks of elevated SCC

***requires intramammary antibiotic treatment

Question 47

characteristics of staph aureus mastitis

Answer 47

invades deep tissue, likely forms abscesses

can be clinical or subclinical

cyclical shedding style

treatment response can be very poor, but can try intramammary abs

Question 48

characteristics of strep agalactiae mastitis

Answer 48

very uncommon now, but still a major contagious mastitis pathogen

if there is an outbreak, it is like wildfire

can treat with short intramammary abs

Question 49

characteristics of mycoplasma bovis mastitis

Answer 49

emerging pathogen on dairy farms, not responsive to antibiotics, often involves multiple quarters, can have concurrent septic arthritis or pneumonia and hematogenous spread

rely on strict biosecurity to prevent it

Question 50

Non-Aureus Staph characteristics

Answer 50

mild clinical mastitis or subclinical only
**usually heifers
usually only infects superficial mucosal surfaces, can self cure or respond to shrot term abs treatment

Question 51

what proportion of clinical mastitis cases will be gram neg, gram pos, and culture negative?

Answer 51

all 1/3!