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Flashcards in Mastitis Deck (59)
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1

WHat are the 2 forms of mastitis? Which is ht emost common?

- Clinical
- Subclinical [most common]

2

What are the 2 forms of clinical mastitis?

Dry [environment] and lactation [contagious] infections

3

Weh is most dry mastitis noticed?

First 100d lactation

4

What is orbeseal?

Inert teat canal sealant prevents bacterial colonisation of ducts in dry period

5

How are contagious and environmental forms of mastitis spread?

contagious - in milking parlour
environmental - everywhere else but may also be spread in parlour

6

Are specific bacteria contagious or environmental? Give egs.

No - though some are more HOST ADAPTED [contagious]
- Strep agalactiea
- Staph areus
- Strep dysgalactiea
- Strep uberus
- E. Coli
and some more OPPORTUNISTIC [environmental]

7

Which type of mastitis causing bacteria (contagious or environmental) are most genetically diverse?

environmental

8

Where is klebsiella found?

Moist conditions environmentally, esp wood shavings and in the milk

9

What does a high bulk tank SCC indicate? Low SCC?

- High = contagious, low severity, majority subclinical disease
- Low = low numbers of environmental, high severity clinical disease cases

10

What is the national average incidence of clinical masitits cases?

35/100 cows/year [wide range]

11

Which area of the UK has a higher than average incidence of mastitis and why?

SE - majority of cows housed indoors on straw beds rather than pasture or cubicles

12

What is the most common severe, opportunistic, environmental bacterial cause of mastitis?

E Coli

13

How may incidence of disease be >100%?

Some cows contracting infections multiple times a year

14

Why are low SCCs associated with more severe disease?

No innate immunity in the herd

15

What impacts does mastitis have for the farmer (other than cow welfare)?

- Quantitiy of milk
- Quality of milk (ABx residues, $ penalty for >200,000SCC)
- ~£100 per case lost roughly

16

What predisposing factor may lead to mastitis?

Poor teat score - keratitis, teat prolapse

17

What is the main sign seen in clinical mastitis?

Changes in milk - colour and clumps

18

What are the grades of mastitis?

- Grade 1: Milk change only, v yield
- Grade 2: Acute = milk changes, udder changes
Chronic = persistent form of acute
- Grade 3 = Systemically sick cow

19

WHat are the main bacteria involved in clinical mastitis? Which are less common agents?

- Strep agalactiae [subclin only, found only in milk]
- Strep dysgalactiae [teat injuries and ulcers, also found tonsils]
- Strep uberis [envornmental]
- Staph aureus [contagious]
- E. COli [environmental]
> Klebsiella, salmonella, yeasts, bacillus cereus, mycoplasma

20

How is subclinical mastitis diagnosable?

- no visable changes in milk or cow
- ^ SCC
- + CMT (Californian mastitis test)
- v milk yiled

21

What does the Californian milk test involve?

- Clean teat, strip
- sample, add reagent (essentially washing up liquid)
- assess for viscosity
> ^ viscosity = +

22

Which bacteria are responsible for chronic or sub-clinical mastitis?

- S aureus
- S uberis
- S agalctiae
Corynebacterium bovis [minor pathogen, cow wont respond as cannot casue disease - good biomarker/indication of teat clceanliness

23

What should be specifically looked at on clinical exam of the dairy cow?

> udder exam
- inspection
- palpation (udder, teat canal, cistern)
- LNs
> milk exam (before CMT) - if clotted = clinical mastitis
> CMT

24

What are the treatment options for mastitis?

> ABx (generally broad spec eg. macrolide and penicillin)
- systemic
- intramammary (DRY)
- intramammary (LACTATION)
> Oxytocin (enourage milk let down)
> NSAIDs
> corticosteroids
> fluid therapy, Ca, dextrose - support sick cow

25

Why should dry and lactating intramammary ABx not be mixed up?

dry = ^ withdrawal
lactating = too short an action will not be effective

26

Is culturing recommended for mastitis?

Yes!
- clinical presentation will not differentiate causes
Usually advocated for recurrent cases, persistent infection, ^ SCC (save ££)
- freeze milk sample if farmer not wanting culture initially so can culture after if Tx fails

27

What are the different forms of samples that can be taken?

- bulk tank
- pooled single cow (all quarters)
- individual quarter sample (best)
> Steralise teat end, 2 pre-strips, 2ml sample in sterile container.

28

Do may cultures return useful results? What other assessment may be used?

- 40% sterile
- always some contamination (aim for can use PCR
- do not mix up sample containers, PCR will have preservative that kills bacteria (not good for culture!)

29

What type of disease do contagious organisms usually cause? HOw is this spread?

- subclinical
- spread cow to cow at milking
- organisms prefer linving in udder and teat skin

30

Give 4 main contagious bacteria associated with mastitis?

- S agalactiae (rare, found in udder only)
- S dysgalactiae (tonsils, udder, teat lesions)
- S aureus (can hide from immune system, ^ resistence -> persistnet infection and abscesses)
- (S uberis) - initially an environmental pathogen from damp straw, can spread between cows