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
