Flashcards in Mastitis Deck (59)
WHat are the 2 forms of mastitis? Which is ht emost common?
- Subclinical [most common]
What are the 2 forms of clinical mastitis?
Dry [environment] and lactation [contagious] infections
Weh is most dry mastitis noticed?
First 100d lactation
What is orbeseal?
Inert teat canal sealant prevents bacterial colonisation of ducts in dry period
How are contagious and environmental forms of mastitis spread?
contagious - in milking parlour
environmental - everywhere else but may also be spread in parlour
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]
Which type of mastitis causing bacteria (contagious or environmental) are most genetically diverse?
Where is klebsiella found?
Moist conditions environmentally, esp wood shavings and in the milk
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
What is the national average incidence of clinical masitits cases?
35/100 cows/year [wide range]
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
What is the most common severe, opportunistic, environmental bacterial cause of mastitis?
How may incidence of disease be >100%?
Some cows contracting infections multiple times a year
Why are low SCCs associated with more severe disease?
No innate immunity in the herd
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
What predisposing factor may lead to mastitis?
Poor teat score - keratitis, teat prolapse
What is the main sign seen in clinical mastitis?
Changes in milk - colour and clumps
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
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
How is subclinical mastitis diagnosable?
- no visable changes in milk or cow
- ^ SCC
- + CMT (Californian mastitis test)
- v milk yiled
What does the Californian milk test involve?
- Clean teat, strip
- sample, add reagent (essentially washing up liquid)
- assess for viscosity
> ^ viscosity = +
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
What should be specifically looked at on clinical exam of the dairy cow?
> udder exam
- palpation (udder, teat canal, cistern)
> milk exam (before CMT) - if clotted = clinical mastitis
What are the treatment options for mastitis?
> ABx (generally broad spec eg. macrolide and penicillin)
- intramammary (DRY)
- intramammary (LACTATION)
> Oxytocin (enourage milk let down)
> fluid therapy, Ca, dextrose - support sick cow
Why should dry and lactating intramammary ABx not be mixed up?
dry = ^ withdrawal
lactating = too short an action will not be effective
Is culturing recommended for mastitis?
- 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
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.
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!)
What type of disease do contagious organisms usually cause? HOw is this spread?
- spread cow to cow at milking
- organisms prefer linving in udder and teat skin