Mastitis Treatment Flashcards
What is mastitis control at its simplest level?
When will current infections cure?
Mastitis at its simplest level is about the prevention of NEW infections in a herd….
In the modern dairy herd, cure of existing infection will occur during the dry period – recent research shows us this – pathogen specific cure rates are very high during the dry period, even for S. aureus
Infection can be from various environmental sources - how can we try to avoid or reduce this?
This could involve reducing infection pressure in buildings – loafing space, ventilation, water quality, water storage, bedding quality, bedding storage, scraping frequency, lying areas etc
This may also involve reducing infection pressure at pasture – stocking rates, back fencing, management of gateways, common loafing areas, fly control etc
–> much harder and more complex to address!
How can we prevent new infections from infected cows (to other cows?)
Often focussed on treatment and/or culling
Assumes infected cows transmit infection to uninfected herd mates
Reactive approach
Over-reliance on antibiotic treatment unsustainable
…transmission from other infected cows generally much easier to limit/stop (parlour)
Whilst Andy (who he, he sounds useful) has described approaches to treatment, we have to remember that this is not sustainable long term, particularly during the current climate (just thought this sentence was good but didnt wanna remove Andy)
As part of the treatment for mastitis, explain the aseptic infusion techqniue for administration of intra-mammary therapy?
As part of the treatment for mastitis, why do we use the aseptic infusion techqniue for administration of intra-mammary therapy?
Aseptic infusion technique
- Risk of new infection
- Coliforms (e.g. E. coli)
- Yeasts (e.g. Candida spp.)
- Important when treating clinical/subclinical inf.
- REALLY important when drying-off cows!
In theory and simple terms, how do we treat clinical mastitis during lactation?
Identify bacterial pathogen…
…select suitable antibiotic
…treat for suitable length of time…
Why, in practice, is mastitis treatment problematic, espeically during lactation?
Pathogen often unknown at time of treatment…!!!!
Vast majority of clinical mastitis cases are not treated by a veterinary surgeon… Farmers treat her. Otherwise you would be called out a lot.
Many factors, other than pathogen and choice of antibiotic, are the basis for success/failure. Mostly comes down to the cow!
Why is the pathogen often unknown at the time of treatment?
Reliant on farm staff to have aseptic sample collection technique…and remembering to sample!
A lot of interest in RAPID diagnostic plates (18-24 hours) to culture a Gram+ or Gram-
…but differentiating between some is very hard to do!
…and is a ‘no growth’ really a no growth…? Or have we not left it long enough?
This is mostly done on the farm.
Strep – Penicillin
E.Coli – may not need to treat?
BUT research SO FAR indicates culture-based treatment approaches associated with a poorer outcome
What are the key points for mastitis treatment?
Many products available BUT VERY FEW comparative studies (dry or lactating products)
Dry cow therapy has much BETTER EFFICACY than lactating cow therapy for curing intra-mammary infections (Approx. 90% vs 50%). Much more likely to cure intra mammary when dry (90%+) then in lactation
WHY?
Trying to treat infection when full of milk = harder
Hostile environment when not in milk = easy.
AB dry cow products- more mg of product (not worried about withdrawal) and last above MIC for longer
MORE VARIATION between COWS, FARMS & PATHOGENS (and strains) than between products
DOSING STRATEGY (how long you treat for) and COW FACTORS are much more important than choice of product…
If the farmers missed clinical signs at the 1st millking, what is the chance of cure? Why?
RAPID IDENTIFICATION IS CRUCIAL…
1st milking critical
If miss clinical signs the chance of cure is reduced by 40-50%… Infection more established and late getting to it
Examine MILK, UDDER and COW
What is grade 1,2 and 3 of mastitis?
Grade 1: milk changes only
Grade 2: milk changes and swollen udder
Grade 3: above…plus cow is ill
How and what COW and FARM factors can affect chance of cure?
COW and FARM factors affect chance of cure…
The cow SCC, her parity (how many calving’s, 3 calving’s probably about 5yo), age and # quarters affected…
The farm bulk milk SCC and prevalence of infection… High cell count where likely to be staphs? Or low likely to be cloiforms
How useful are antibiotics with regards to treating mastitis?
ANTIBIOTICS ARE WORTHWHILE
But not 100%…
Antibiotics cure symptoms
~ 90%? Got rid of sign or clots; may not have actually got rid of the infection
Antibiotics cure bacterial infection
~50-60%?
Non-antibiotic treatment much less! My get 80% symptomatic and 30% pure cure
With pathogens, do gram positive or negative not often need a long course of treatment?
…what about Gram-negative pathogens?
Often don’t need a long course of treatment
What should the route of antibiotic be?
ROUTE OF ANTIBIOTIC SHOULD BE INTRA-MAMMARY
Little evidence that injectable (systemic) antibiotic treatment is better…
…or that it improves cure rate in combination
Why is duration of treatment important?
DURATION of treatment is important
The vast majority of antibiotic tubes are NOT used per data sheet. If you follow this you can then put milk back in tank according to the sheet
Minimum three days?
Extended treatment improves chance of cure – consider 5 to 8 days?
Can chance of cure be 100% in lactation?
Remember chance of cure is never 100% in lactation
If you have a HIGH cell count herd, Typically bulk milk SCC>200 cells/ml, what pathogens are more likely?
‘Contagious’ mastitis pathogens more likely Gram-positive pathogens predominate
e.g. S. aureus, Enterococcus spp., S. uberis
Look at this decision tree for drying off cows and whether to treat - sorry didnt know how to put into a question!
