Mastitis - Clinical presentation

Question 1

What are the presentations of mastitis?

Answer 1

clinical or subclinical (more common)
Dry period or lactation infection
Contagious (mostly) or environmental

Question 2

What is a dry cow infection?

Answer 2

One where the cow gets mastitis within the first 100 days after calving (i.e. early lactation)

Question 3

What is Orbeseal?

Answer 3

An intrammammary suspension to put in the teats to prevent infection.

Question 4

How do the bacteria generally vary between contagious and environmental causes for mastitis?

Answer 4

There is a scale which works generally:
CONTAGIOUS 
S. agalactiae
S. aureau
S. dysgalactiae
S. uberis
E. coli
ENVIRONMENTAL

Question 5

General causes of mastitis

Answer 5

Multifactorial:

Host, environmental, agent

Question 6

Average UK incidence of mastitis

Answer 6

35 per 100 cows per year (40-70 quarter infections)

SE England: 45 cases/100 cows/year

Question 7

What is an average bulk tank somatic cell count?

Answer 7

184,000/ml

Question 8

What does a bulk milk tank reading of <100,000 indicate?

Answer 8

Fewer clinical mastitis cases but typically cases are more severe (e.g. E.coli infections)

Question 9

Why bother with mastitis?

Answer 9

MILK QUANTITY (actual and potential milk)
MILK QUALITY (residues, penalty for high SCC)

Question 10

Average cost per mastitis case?

Answer 10

£100 per year +/-

Question 11

What is needed for clinical mastitis?

Answer 11

Pathogen exposure, entry into teat and mammary gland, establishment of infection.

Question 12

True/false - in mastitis there are always changes in the milk

Answer 12

True (colour, spots, clots etc)

Question 13

How is clinical mastitis graded?

Answer 13

Grades 1-3

Question 14

Describe grade 1 mastitis

Answer 14

milk change only, decreased milk yield

Question 15

Describe grade 2 mastitis

Answer 15

Subdivided into acute and chronic
ACUTE = milk changes, changes in the udder, milk yield decreased
CHRONIC = as acute but persistent changes (udder and milk)

Question 16

Describe grade 3 mastitis

Answer 16

As grade 2 but a systemic sick cow (typically E.coli or S.aureus)

Question 17

Pathogens involved in acute/clinical mastitis - 6

Answer 17

(S. agalactiae) - subclinical
S. dysglacactiae (teat injury)
S. uberis (envi)
S. aureus (contagious)
E. coli
Exotic agents: Klebsiella, Salmonella, yeasts, Bacillus cereus, Mycoplasma.

Question 18

Will you have a positive California Milk Test (CMT) with subclinical mastitis?

Answer 18

Yes

Question 19

How would you perform a CMT (OSCE!!!)?

Answer 19

wipe teat,
wear gloves (show best practice)
strip pre-milk (highest SCC)
take sample
remember paddle orientation
add reagnet to disrupt membrane and cause DNA to branch out
Assess - there is some grading as to the outcome (slight/very positive result)

Question 20

Pathogens implicated in chornic/sub-clinical mastitis

Answer 20

S.aureus
S.uberis
S.agalactiae
Corynebacterium bovis

Question 21

What are the important aspects of mastitis history?

Answer 21

duration, development, stage of lactation and gestation, age, treatment and its response, previous episodes, SCC data from NMR, other cases in herd?? records?

Question 22

What are the important aspects of mastitis clinical exam?

Answer 22

systemic clinical exam
udder exam (inspect, palpate, LNs)
milk exam
Milk sample - CMT

Preliminary Dx and Tx

Question 23

Is Baytri a systemic treatment?

Answer 23

Yes

Question 24

What features do ABs need to have for mastitis treatment? 3

Answer 24

systemic,
intramammmary during lactation
intrammammary in a dry cow
ABOVE TWO ARE DIFFERENT, DO NOT CONFUSE!!!

Question 25

What does AB choice depend on?

Answer 25

sensitivity, pharmacokinetics, availability, costs, herd history, withdrawal time

Question 26

Other treatment options for mastitis - 5

Answer 26

``` Oxytocin - helps milk letdown which is important to encourage in mastitis cases NSAIDs Corticosteroids - controversial fluid therapy -esp toxic mastitis calcium dextrose ```

Question 27

Why do a culture?

Answer 27

You can never tell on basis of clinical presentation (remember you can use a PCR to determine specific pathogen) AB sensitivity Select your samples (recurrent, persistent, risein SCC)

Question 28

When should you freeze sample?

Answer 28

Always (in case of treatment failure)

Question 29

What are the different milk samples that can be taken? 3

Answer 29

Bulk tank sample Pooled sample of one cow Individual quarter sample

Question 30

How should you take a sample?

Answer 30

``` Cleanse udder Swab teat end 2 pre-strips 2ml in sterile container Label name, cow number and quarter USE GLOVES!! ```

Question 31

For what reasons does prevention vary?

Answer 31

Per bug and per farmer. Starts with records.

Question 32

How many samples on average return sterile?

Answer 32

40%

Question 33

How should you assess your performance?

Answer 33

on % of contamination (aim for <10%)