La Medicine Iii -- Mastitis

Front 1

What is the mammary gland?

Back 1

-- modified sweat gland

-- acini of columnar epithelial cells emptying into a duct network

Front 2

What are the products of mammary columnar epithelial cells? Purpose of these products?

Back 2

-- colostrum and milk

-- provide energy, water, electrolytes, vitamins, minerals, amino acids, some whole proteins (e.g. IgG) and cells

Front 3

How do cells and proteins get into the milk/colostrum? Types of cells?

Back 3

-- are transported into colostrum or milk from the dam's circulatory system or local lymphoid tissue

-- sloughed epithelial cells, a few immune cells

>> "somatic cells"

Front 4

What happens when there is inflammation of the mammary gland (mastitis)? With increasing severity of inflammation?

Back 4

-- influx of neutrophils into milk

-- leakage of serum protein and electrolytes

-- increasing severity of inflammation

>> clots or chunks in the milk (fibrin)

>> milk becomes serous or hemorrhagic

>> normal fat/protein content decline

>> bacterial products, spoiled or putrid smell

Front 5

Use of a strip cup allows detection of what?

Back 5

-- flakes, chunks, or clots in the milk

-- milk from different quarters can be compared

Front 6

What is the california mastitis test (CMT)? CMT detects what, and where does this substance come from?

Back 6

-- milk is mixed with detergent in a cup

-- detergent lyses cells, causing DNA to form strands and making milk mixture gelatinous

-- DNA usually comes from neutrophils, microbes

Front 7

CMT can detect only clinical mastitis. T/F?

Back 7

-- False!

-- CMT can detect both clinical and subclinical mastitis

Front 8

CMT Score indicates what?

Back 8

-- somatic cell counts of the milk

Front 9

CMT score of "none" indicates what cell count range?

Back 9

-- 0 - 200,000 cells/mL

-- usually a sterile quarter

>> even with this score, there could be a few neutrophils

Front 10

CMT score of "trace" indicates what cell count range?

Back 10

-- 200,000 - 400,000 cells/mL

Front 11

CMT score of "1" indicates what cell count range?

Back 11

-- 400,000 - 1,200,000 cells/mL

Front 12

CMT score of "2" indicates what cell count range?

Back 12

-- 1,200,000 - 5,000,000 cells/mL

Front 13

CMT score of "3" indicates what cell count range?

Back 13

-- over 5,000,000 cells/mL

-- "pretty gelatinous" at this point

Front 14

What is milk cytology used for? How common is this?

Back 14

-- not a common diagnostic method

-- used if fungal infection is suspected

-- may be useful if milk is very watery

Front 15

What is milk culture used for?

Back 15

-- diagnosis of pathogens that are causing mastitis

e.g. coagulase negative staph

Front 16

How much sodium and potassium are usually present in milk? How do these values compare to blood?

Back 16

-- 22 mEq/L Na+ (6-7x lower than blood)

-- 38 mEq/L K+ (6-7x higher than blood)

Front 17

How do electrolytes change with inflammation?

Back 17

-- concentrations become more like serum with weakening of blood/milk barrier as serum leaks into milk

Front 18

Electrical conductivity of milk can be used to determine what?

Back 18

-- detects inflammation based on electrolyte increase in milk

-- measured by the milking machine or hand held

-- sensitive screening test to ID sick cows

Front 19

Individual cow milk somatic cell count?

Back 19

-- test for milk quality

-- usually measured in bulk (whole dairy) rather than for individual cow

Front 20

Dairy coop requires < ______ cells/mL in bulk tank for sale.

Back 20

-- <750,000 cells/mL

Front 21

Milk to be sold as jug milk must have <_____ cells/mL.

Back 21

-- <40,000 cells/mL

Front 22

Lower quality milk is used for?

Back 22

-- making evaporated milk

-- made into mushroom soup for astronauts

-- etc.

Front 23

Linear score for milk?

Back 23

-- 0: <19,000

-- 1: 19,000 - 36,000

-- 2: 36,000 - 72,000

Front 24

For the linear milk score, for each increase of score over 2, there is a ____lb loss of milk/cow/day.

Back 24

-- 1.5lb loss of milk/cow/day

Front 25

Most common cause of mastitis?

Back 25

-- almost always the result of microbial infection of the mammary gland

-- most infections are bacterial

-- small number of fungal/algal infections

Front 26

MCF also causes mastitis. T/F?

Back 26

-- true (targets mucosal surfaces)

Front 27

How do bacteria get into the mammary gland?

Back 27

-- bacteria climb up from teat end

-- penetrating injuries

-- hematogenous infections

Front 28

Most common route of infection?

Back 28

-- bacteria enter from teat orifice and climb up teat into the mammary gland

Front 29

Categories of microbial effects on the mammary gland?

Back 29

-- epithelial colonizers

>> mild-to-moderate inflammatory responses

>> milk fermentation/mucosal inflammation

-- invasion of parenchyma (lg. rafts cell sloughing, loss of blood-udder barrier)

-- fibrous reaction and abscess formation

-- thrombosis and ischemia

-- severe local or systemic vasoactive effects

>> endotoxins from gram negative bacteria

Front 30

Clinical presentations of mastitis (5)?

Back 30

-- subclinical mastitis

-- clinical mastitis, acute or chronic

-- toxic mastitis

-- gangrenous mastitis

-- mammary abscesses

Front 31

Which kind of mastitis is most common?

Back 31

-- subclincal mastitis (by far)

-- 15-40x more common

Front 32

Define subclinical mastitis.

Back 32

-- detectable or undetectable mammary inflammation

-- udder and milk appear normal

-- 15-40x as many subclinical cases as clinical cases on average

Front 33

Why is subclinical mastitis important?

Back 33

-- can flare up into clinical mastitis

-- cow may be a carrier of infection

-- may cause production losses

>> dec. quality/quantity of milk

Front 34

How might subclinical mastitis flare up into clinical mastitis?

Back 34

-- may have subclinical mastitis during the dry period, which becomes clinical when milk production begins and bacteria have milk to ferment, etc.

Front 35

General indicators of mastitis?

Back 35

-- painful

-- walk awkwardly

-- don't want to lie down

-- push calf away

-- erythema/swelling/edema/firmness of udder

Front 36

Transition of subclinical to clinical mastitis?

Back 36

-- cow starts to look uncomfortable

-- milk is abnormal upon testing

Front 37

What is acute clinical mastitis?

Back 37

-- inflammation becomes severe enough to visibly affect milk quality, the udder, or the dam's level of comfort

Front 38

Acute clinical mastitis can result from what?

Back 38

-- acute infection

-- rapid periparturient worsening of infection acquired during a non-lactating period

-- flare-up of a chronic infection

Front 39

Milk quality is judged by?

Back 39

-- visible appearance (clots/chunks/thick, presence of blood, watery nature), abnormal smell, strip cup, CMT

-- lab tests (electrolyte content, somatic cell count, culture)

Front 40

Do cows with mastitis usually have a fever?

Back 40

-- no

Front 41

Pathogens that may be more likely to cause fevers with mastitis?

Back 41

-- Mycoplasma

-- Pasteurella

-- Candida

-- Staph aureus

Front 42

Milk production with acute clinical mastitis? Appetite? Heartrate?

Back 42

-- slightly to moderately reduced

-- appetite may be slightly reduced

-- may see tachycardia

Front 43

Main diagnostic test with acute clinical mastitis?

Back 43

-- bacteriologic culture

Front 44

Why is it important to culture with acute mastitis cases?

Back 44

-- more targeted use of antibiotics

-- more accurate determination of prognosis

(some easier to cure than others)

-- better tailoring of prophylactic measures

(contagious vs. environmental)

Front 45

Treatment of acute mastitis?

Back 45

-- 3-7 days of intramammary abx

-- systemic abx if cow is very sick

-- NSAIDs

-- more frequent stripping of milk

Front 46

Why is milk stripping recommended?

Back 46

-- keep clots/clumps/flakes from building up

-- bacteria, inflammatory cells, etc. are building up in the teat cistern

>> want to get them out

Front 47

Why should cows with mastitis be milked last?

Back 47

-- want to decrease likelihood of spreading the infection

Front 48

Mastitis late in lactation may result in which outcomes?

Back 48

-- drying cow off early and trying to keep her from getting too fat during dry period

-- culling cow (if not bred back)

Front 49

Acute clinical mastitis is usually due to which pathogens?

Back 49

-- gram positive bacteria

Front 50

Toxic mastitis is usually due to which pathogens?

Back 50

-- gram negative bacteria

Front 51

What is toxic mastitis? Often due to?

Back 51

-- gram-negative intramammary infection with systemic effects due to endotoxin (coliform)

-- often explosion of dry cow infection with onset of lactation

Front 52

Two peaks in endotoxin release occur when? What does this mean wrt disease course?

Back 52

-- rapid growth phase

-- die-off phase

-- two peaks in endotoxin release

-- second makes cow look sicker even though the infection may be gone at that point

Front 53

Course of toxic mastitis infection? What does this mean?

Back 53

-- acute toxic infection leads to a massif inflammatory response within 16-24h

-- massive kill-off of bacteria causes big endotoxin release

>> cow may look sicker but the quarter may already be sterile

>> could also spread systemically

Front 54

Clinical signs of toxic mastitis?

Back 54

-- serous/watery/bloody milk

-- warm/swollen/red infected quarter (udder)

-- depression, tachycardia, tachypnea, hypothermia, cold extremities, ruminal atony, scleral injection, poor capillary refil, weakness, recumbency, toxic MMs

Front 55

Why is coliform mastitis more likely to persist as an active infection in the early postparturient period?

Back 55

-- cortisol release with parturtion causes immune suppression

Front 56

Down, shocky, postparturient cows with tachycardia may also have?

Back 56

-- hypocalcemia

-- metritis

-- abomasal volvulus

-- differentiate by looking at udder

>> may be difficult to see if cow is down

Front 57

Diagnosis of toxic mastitis?

Back 57

-- clinical signs

-- culture

-- bloodwork: panleukopenia, left shift, neutropenia, toxic changes (gram negative sepsis) and hyperlactemia, azotemia, metabolic acidosis, high anion gap, hypoproteinemia, hyponatremia, hypochloremia (shock)

Front 58

Important to distinguish signs of toxic mastitis from which other diseases?

Back 58

-- hypocalcemia, hypophosphatemia, hypokalemia

-- abomasal volvulus

-- toxic metritis

Front 59

Treatment of toxic metritis?

Back 59

-- IV/oral fluids (hypertonic saline or calcium?)

-- NSAIDs, e.g. flunixin meglumine

-- supportive care for weakness/recumbency

-- abx (ceftiofur, aminoglycosides, polymixin B)

-- frequent stripping of the udder to flush toxins

>> can give oxytocin to help with letdown

-- intramammary abx + polymixin B

Front 60

What is gangrenous mastitis?

Back 60

-- features of both acute clinical and toxic mastitis

Front 61

Clinical signs of gangrenous mastitis?

Back 61

-- fever

-- hot, swollen quarter

-- discomfort

-- chunky, purulent milk >> sanguinoserous

-- systemic signs of toxemia

-- affected quarter goes from pink to red-purple to blue, becomes cold

-- gas may be palpated within the gland or expressed during stripping

Front 62

Diagnosis of gangrenous mastitis?

Back 62

-- signs and culture

-- leukocytosis

Front 63

Treatment of gangrenous mastitis?

Back 63

-- similar to toxic mastitis

-- abx for gram (+) bacteria

-- toxic agents (e.g. 2% chlorhex) may be injected through the teat end in an attempt to sterilize the quarter

-- advanced gangrenous quarters may be removed surgically or may slough sponaneously

Front 64

Loss of one quarter results in ___% of prior milk production?

Back 64

-- 85%

Front 65

Mammary abscesses can be?

Back 65

-- focal

-- involve the entire gland

Front 66

Mammary abscesses may affect milk production if?

Back 66

-- if the entire gland is involved

-- otherwise, most cows appear normal and have normal appearing milk

Front 67

Focal abscess signs?

Back 67

-- firm/fluctuant swelling

-- +/- erythema, painfulness

Front 68

Entire gland abscess signs?

Back 68

-- gland feels firm and may be painful

-- secretion looks like pus

Front 69

Diagnosis of mammary abscess?

Back 69

-- clinical signs

-- culture

-- ultrasound/aspiration for focal abscesses

Front 70

Treatment of focal abscesses?

Back 70

-- lancing, flushing, antimicrobial treatment

-- may wait until the cow is dry

Front 71

Treatment of abscessation of entire gland?

Back 71

-- as per acute mastitis

-- if milk-producing tissue is compromised, may sterilize the gland with antiseptic infusions +/- removal of teat end to allow drainage (salvage)

Front 72

Highest prevalence of most forms of mastitis occurs when? Why?

Back 72

-- last few days of pregnancy and early postparturient period

-- includes infections from dry period which flare up with the onset of lactation, immunosuppression, weakness of the teat sphincters, inc. recumbency, greater environmental contamination with milking herd, transmission during milking

Front 73

Strep ag includes?

Back 73

-- strep agalactiae

-- strep dysgalactiae

Front 74

Strep non-ag includes?

Back 74

-- strep uberis

-- strep bovis

Front 75

Common isolates from acute clinical mastitis include?

Back 75

-- Strep agalactiae, Strep dysgalactiae

-- Strep uberis, Strep bovis

-- Staph aureus, coag-neg. Staph

-- pasteurella (mainly in sheep)

-- Listeria monocytogenes (zoonotic)

-- mycoplasma

-- candida

Front 76

Common isolates from toxic mastitis include?

Back 76

-- E. coli

-- Klebsiella

-- Salmonella enteritides

-- Pasteurella hemolytica

-- Pseudomonas aeruginosa

Front 77

Common isolates from gangrenous mastitis include?

Back 77

-- Staph aureus

-- Trueperella spp (Arcanobacter, Actinomyces, Corynebacterium)

-- coag. neg. Staph

-- Pasteurella (mainly in sheep)

-- Enterococcus faecalis

Front 78

Common isolates from abscesses?

Back 78

-- Trueperella pyogenes

-- Staphylococcus aureus

Front 79

Cows with pasteurella mastitis?

Back 79

-- usually have it secondary to Pasteurella pneumonia

Front 80

Keep what in mind about toxic mastitis?

Back 80

-- it implies the activity of endotoxin but not necessarily the continued presence of the organism

Front 81

One of the worse pathogens in mastitis is? Why?

Back 81

-- Staph. aureus

-- causes gangrenous mastitis

-- many antibiotic resistant strains

Front 82

Does pasteurella cause abscesses in mammary glands of sheep?

Back 82

-- no (weird)

Front 83

How are contagious bacteria causing mastitis different from environmental bacteria causing mastitis?

Back 83

-- contagious: reservoir for the bacteria is within the mammary gland

-- environmental: reservoir for the bacteria is outside of the mammary gland

Front 84

Contagious mastitis organisms?

Back 84

-- Strep agalactiae and dysgalactiae

-- Staph aureus

-- Mycoplamsa

Front 85

Which contagious organisms are the worst for the cow? Why? Assoc. with which other disease processes?

Back 85

-- Staph aureus

-- Mycoplasma

-- also assoc. with lameness, resp. disease, reproductive failure

-- generally considered permanent infections

Front 86

Contagious organisms are transmitted how?

Back 86

-- milking procedure

-- milking machine

Front 87

Control of contagious organisms?

Back 87

-- treat inside the mammary gland

-- worry about carrier cows

Front 88

Control of environmental organisms?

Back 88

-- increased hygiene

-- prevent fecal material from getting onto teat and into the gland

Front 89

Herds that have problems with mastitis and can't get the tank cell count down?

Back 89

-- likely have some form of contagious mastitis, e.g. Staph aureus or mycoplasma

Front 90

Coagulase negative Staphs are considered?

Back 90

-- quasi-contagious

-- reservoir is the teat skin (not within gland)

-- same control mech. as contagious microbes

Front 91

Environmental organisms?

Back 91

-- E. coli and other coliforms

-- Strep uberis, bovis

-- Strep non-Ag

-- Pseudomonas

-- Trueperella

-- Pasteurella (sheep)

-- fungi

Front 92

Gram positive organisms tend to cause?

Back 92

-- acute mastitis or abscesses

Front 93

Gram negative organisms tend to cause? Exception?

Back 93

-- toxic mastitis

-- cows vaccinated against endotoxin may develop acute mastitis without toxic signs when infected by gram-negative pathogens

Front 94

Many mammary infections occur how (regardless of reservoir)?

Back 94

-- during milking procedure

-- due to inadequate cleansing and drying of the teat ends

-- contamination of milking machine or milkers' hands, liner slip, or inadequate/irreg. vacuum cycling

-- some inf. occur due to direct invasion or hematogenous spread

Front 95

Control of contagious mastitis (milking parlor management)?

Back 95

-- barrier teat dip after milking

-- dry cow abx tx (end of lactation)

-- milk inf. cows last/ w/ separate milking claw

-- clean milking claw with hot water or germicide after milking inf. cows (backflushing)

-- wash and dry teats with individual towels

-- milkers need clean hands/wear gloves

Front 96

Control of contagious mastitis (herd management)?

Back 96

-- culture new additions to the herd

-- cull persistently inf. cows

(esp. Staph aureus, mycoplasma)

-- minimize teat lesions (from chapping, frostbite, stepped-on teats, lacerations, milking damage)

-- heifers may benefit from dry cow abx tx during gestation if Staph aureus is a problem w/ heifers

Front 97

Dry cow antibiotic treatment? Goal?

Back 97

-- tx every quarter of every mammary gland q1y

-- reduce number of cows in entire herd that are affected (prevalence of mastitis)

Front 98

Teat dipping in barrier germicide after each milking goal?

Back 98

-- prevent new mammary glands from being infected

-- reduces new cases of mastitis
(incidence of mastitis)

Front 99

Control of environmental mastitis (buildings/equipment)?

Back 99

-- ID and remove source (bedding, ponds, mud)

-- keep milking parlor clean

-- keep teat dipper clean

-- check pipelines/water heater
(esp. Pseudomonas)

Front 100

Control of environmental mastitis (cows)?

Back 100

-- clip udders to minimize manure attachment

(+/- tail docking, medial dewclaw removal)

-- milk only clean, dry teats

-- pre-dip teats with germicide before milking

-- offer feed after milking to keep cows standing

-- sterile, single-dose infusion products and sterile infusion techniques (alcohol swab)

Front 101

Vaccination for toxic mastitis? One drawback?

Back 101

-- J5 vx: short-chain polysaccharide mutants, exposed LPS antigens

>> vaccination against endotoxin

>> cross-rxn antibody across G (-) pathogens

>> vaccinated cows have a 70% dec in toxic mastitis and dec in clinical signs

-- coliform mastitis may look like G (+) inf.

>> may prevent inflamm. rxn that kills E. coli