Mastitis 1 Flashcards
a cow is at risk of developing mastitis the most during what 2 periods?
just after the dry off period
just before calving
list 5 characteristics of active invulution of the udder
- 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
list 4 things that happen during lacto/colostrogenesis
- 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
many intramammary infections are acquired during _____ and what is the result of this?
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
main 2 reasons why cows get mastitis?
failure of host immunity AND/OR overhwleming exposure
describe what the innate immunity of the udder is like
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
the teat canal is liend with keratin, what does this do?
it is waxy, has antimicrobial properties, and provides a physical barrier to bacterial migration into the teat
somatic cells in the normal udder are made up of what? what about when there is an infection
macrophages»neutrophils, lymphocytes, epithelial cells
during infection: mostly neutrophils
true or false: it is harder for immune cells to do their job in the milk compared to the blood
true
what impairs the immune defenses on the teat/
damage to the teat end, or immune suppression (nutrition deficinecy, other diseases, genetics, hormones, stress)
teat end hyperkeratosis is caused by what
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
should you normally see a ring around the teat canal?
NO
why is hyperkeratosis of the teat a problem? who even cares bestie?
it predisposes to bacterial colonization! oh no! a score of 3 or 4 increases risk of both contagious and environmental mastitis
a cow named JESSIE needs her teats assessed. how you gonna do that bestie?
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
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?
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!
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?
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
psuedocowpox can also cause lesions on the teats. what do these lesions look like?
they’re circular and red and can also be in the mouth. typical pox lesions. this takes a while to go away
what are some common bedding materials for lactating cows? what about dry cows and heifers?
straw, shavings, manure solids, compost pack, sand
can be in stalls but are usually outside with straw packed bedding
what kind of bedding has the least risks?
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)
what is the acceptable number for colony forming unit per ml for bedding?
fresh bedding should be less than 5000cfu/ml and bedding should always be less than 1 million cfu/ml
true or false: all bedding is bad after a certain amount of time
true! E coli and klebsiella will be high in old bedding regardless of type!
you’ve been asked to go check out a dairy farm and evaluate the cow’s udders for cleanliness. how will you do this?
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
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
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
true or false: the milking machine is responsible for many mastitis cases on farm
false! usually not an issue in most cases
what is the most important “setting” on the milking machine and why?
the teat end vacuum! It needs to be in a narrow range, must remain stable, and can’t be too high!
why is the milking procedure an important factor in mastitis management?
the timing of milk let down MUST be coordinated with application of the milking cluster, it is also a time to examine the udder
milk let down is most effective when you
idk gotta get notes from someone
______ is a major control point for prevention of new infections
pre and post milking teat disinfection
within how many seconds from fore stripping to attaching the milking unit should there be?
60 seconds (more than 90 is delayed and more than 120 is late attachment)
why do we fore strip and what is the proper way to do it?
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
what can happen if you dont allow time for the cow to let down her milk?
it exposes the teat to high vacuum levels which is uncomfy and can lead to teat hyperkeratosis. AND less milk is usually harvested
what is the proper way to do pre dipping?
dip the entire teat and barrel, should apply to a clean teat NOT a dirty one, you need good contact time
why is it important to control environmental mastitis pathogens in particular?
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
proper way to wipe pre dip off?
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
what is the single most important step of the milking routine to prevent new udder infections?
POST DIPPING
should post dips get wiped off?
NOOOOOOOOOO
why is post dipping so important for controlling contagious mastitis pathogens?
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
what is post-prep teat end swabbing?
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
list the contagious udder pathogens
staph aureus
staph agalactiae
mycoplasma bovis
spread from cow to cow during milking procedure
list the environmental udder pathogens
E coli
klebsiella
strep uberus
reservoir in the environment, not spread from cow to cow
there is one pathogen that is opportunistic and commonly affects milking heifers. what is it?
non aureus straph (NAS)–>staph chromogenes usually
it colonizes the skin on the teat and then gets into the udder
true or false: a heifer cow can get infected with NAS before she calves
true! then she will most likely have subclinical, but could be clinical too
list examples of pathogens that are initially acquired in the environment, but then spread from cow to cow once there are enough cows affected
strep uberus
prototheca (an algae)
characteristics of E coli mastitis
acute infection, release of endotoxins, septicemia/bacteremia, systemic infection
large swollen quarter with watery milk]
these cows need systemic therapy
systemic antimicrobials, NSAIDs, fluids
characteristics of klebsiella pneumoniae mastitis
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
characteristics of streptococcus uberus mastitis
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
characteristics of staph aureus mastitis
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
characteristics of strep agalactiae mastitis
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
characteristics of mycoplasma bovis mastitis
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
Non-Aureus Staph characteristics
mild clinical mastitis or subclinical only
**usually heifers
usually only infects superficial mucosal surfaces, can self cure or respond to shrot term abs treatment
what proportion of clinical mastitis cases will be gram neg, gram pos, and culture negative?
all 1/3!
