LA Mastitis Flashcards
What are the 2 anatomical defense mechanisms of the udder?
- suspensory ligaments: lateral lig support the weight of the udder (higher udder = less contact with ground) and median lig. provides weight suport and teat alignment
- teat canal with sphincter (stays open 2 hr post milking) and keratin lining of teat canal (bacteriostatic, sticky to trap bacteria)
What are the 4 somatic cells that act as a defense mechanism for the udder?
- T lymphocytes
- macrophages
- neutrophils
- alveolar cells
What secretory antibody acts as a defense mechanism for the udder?
IgG
________ is the whey protein that increases during udder involution and binds iron which is good because some bacteria need iron.
lactoferrin
Cows with lower levels of _______________ and lactoperoxidase are MORE susceptible to mastitis
lysozymes
what are the 2 time periods that animals are MOST at risk for mastitis?
2 weeks PRIOR to giving birth
2 weeks AFTER giving birth
what is the role of oxytocin as a mammary gland defense?
causes milk let down which flushes the udder and drains any potential pathogens out
what blocks oxytocin?
epinephrine
List the steps to milking a cow:
- put on gloves
- wet the udder, then manually clean the teats (this stimulates oxytocin release in addition to sights/sounds)
- use pre-dip to reduce environmental mastitis and leave on teats for 30 sec minimum, then remove with clean towel
- strip the teat foremilk to remove bacteria and somatic cells – examine the foremilk for garget or flakes
- kink teat cups and then place teat cups onto teats
- after 5-6 min, remove teat cups once milk flow has reduced/stopped
- use post-dip
- remove residual milk from teat cup by back flushing in order to prevent bacteria from one cow being passed to another
- remove cows from parlor and immediately provide feed/water to prevent them from lying down and exposing open teat canals to environmental orgs
__________ is inflammmation of the udder
mastitis
What causes mastitis in small ruminants?
retroviruses – OPP and CAE
T/F: mastitis can be caused by physical trauma (overmilking, vacuum problems, and general trauma)
true
How should you collect a milk sample?
- wipe off teats with towel
- squirt out some milk
- wipe bottom of each teat with alcohol 4x4 until clean (far teats first, then near)
- sample teats (near teats first, then far)
- hold tube horizontally and squirt milk into tube
- put labeled tubes on ice and wash hands
_____________ is an obligate parasite of the udder that is highly contagious. It does not actually invade the tissue, but it lines the duct epithelium and produces local toxins. It causes acute and chronic subclinical mastitis with high SCC counts.
streptococcus agalactia
Which organism is considered the only mastitic organism that can be eliminated from the herd and responds really well to antibiotics (procaine penicillin Intramam.)?
streptococcus agalactia
How can you prevent a streptococcus agalactia infection?
its in transmitted from infected udders to clean udders during milking (hands, cloths, or residual milk)
1. have good milking hygiene (wash hands, use individual paper towels, use back flush system)
2. dry cow treatment
Streptococcus dyslactia is NOT an obligate organism, but is found in the mouth, vagina, and lungs. These infections are not as responsive to antibiotics as S. agalactia are. What risk factors are these infections associated with?
teat end damage or injury
how do you prevent S. dysgalactia infections?
milk clean and dry udders
reduce teat end damage
What organism is considered the “fecal strep” associated with dirty environments and bedding?
Strep uberis
_________ is a contagious bacteria that colonizes the teat and udder skin following an injury (sunburn, freezing, chapping). It is spread between cows during milking (hands or improper procedures).
staph aureus
A cow presents to you with a fever of 104 and a swollen cold edematous udder with a strong line of demarcation. You do TPR and the HR is 110. You milk the cow for a sample and the milk is wine colored with no clots. What is most likely the diagnosis?
gangrenous mastitis
A cow presents to you with a fever of 105 and a swollen, hard, painful udder. You do TPR and the HR is 110 and this cow is dehydrated and recumbent. You take a milk sample and its watery with garget. The agent you cultured is E. coli. What is most likely the diagnosis?
peracute systemic mastitis
Why are organisms involved in staphyloccocus aureus chronic or subclinical mastitis resistant to antibiotic treatment?
the organism invades the walls of the tissues and causes granulomas. The antibiotics cannot penetrate the abscess wall.
What is the treatment for gangrenous mastitis caused by staph aureus?
amputate the teat to get drainage
IV fluids
systemic antibiotics
what is the treatment for peracute and acute staph aureus mastitis?
- fluids – hypertonic (oral or IV)
- antibiotics: tetracycline IV
- analgesics – banamine
- Ca borogluconate/CMPK
- oxytocin and milk out
how do you prevent staph aureus mastitis?
- cull infected individuals to reduce exposure to naive cattle
- milk staph cows LAST
- teat dip ALL cows to reduce colonization
- proper sanitization during milking
- backflush system
__________________ are common inhabitants of bovine and human skin. They are considered opportunists that colonize teat end leasions, teat trauma, viral lesions, etc. They cause acute mastitis with small white flakes and inflamed udder.
coagulase negative staphs (s. epidermidis, s. simulans, s. warneri, s. xylosis)
What is the treatment for mastitis caused by coag negative staphs?
commercial mastitis infusions (sythetic penicillin) 3x intramammary.
to prevent, teat dip and be clean. dont forget to do dry cow treatment.
______________ is an organism that causes “summer mastitis” because it is transmitted by flies and associated with teat injury/laceration. These infections often become chronic and form abscesses.
trueperella pyogenes
_________ are environmental contaminants that are transmitted during the milking process or in the environment. They cause acute mastitis with watery milk secretions containing yellow material (like egg drop soup). The udder of these cows will be enlarged and painful. She will have increased temp, be depressed, and anorexic.
coliforms
A cow presents to you with normal teats and normal udder. The cow herself seems normal as well. The milk secretions appear normal, but the SCC is high. What is the diagnosis?
bonus if you can say what organisms are most likely the cause
subclinical mastitis
contagious orgs
streptococcus
coag neg staphs
rarely coliforms
what is the treatment for mastitis caused by coliforms?
- milk out affected quarter
- anti-inflammatories +/- steroids
- IV antibiotics (tetra)
- fluids (oral or IV) + calcium
how do you prevent mastitis infections that are caused by coliforms?
clean the environment
only milk dry udders
post dip to provide barrier
feed cows after milking to prevent laying down.
why do we do dry cow treatment?
- udder involution – allows tissue to heal and clear infections
- give the cow a rest
- prepare for next lactation – udder tissue develops and colostrum is produced
describe dry cow treatment
- discontinue milking – decrease feed, NO grain, remove water if needed
- infuse dry cow treatment (oil-based antibiotic)
- dip teats with teat dip for barrier
- place in clean environment
A goat presents to you with a fever and is off feed. The teats are hard and and swollen and the milk is mostly normal other than a little bit of silt settling at the bottom of the sample tube. What is the most likely cause of this mastitis?
mycoplasma bovis
How do you perform a california mastitis test?
squirt equal parts of milk to reagnent into the paddle
swirl milk and reagent
look for coagulation
negative = no film
trace = some film but disappears in 15 sec -> subclin mastitis
1 = see film and doesnt disappear –> possibly infected
2 = thick film, slight gel –> most likely infected
3 = very thick precipitation, pours like jelly –> infected
