Flashcards in Mastitis - Clinical presentation Deck (33)
What are the presentations of mastitis?
clinical or subclinical (more common)
Dry period or lactation infection
Contagious (mostly) or environmental
What is a dry cow infection?
One where the cow gets mastitis within the first 100 days after calving (i.e. early lactation)
What is Orbeseal?
An intrammammary suspension to put in the teats to prevent infection.
How do the bacteria generally vary between contagious and environmental causes for mastitis?
There is a scale which works generally:
General causes of mastitis
Host, environmental, agent
Average UK incidence of mastitis
35 per 100 cows per year (40-70 quarter infections)
SE England: 45 cases/100 cows/year
What is an average bulk tank somatic cell count?
What does a bulk milk tank reading of <100,000 indicate?
Fewer clinical mastitis cases but typically cases are more severe (e.g. E.coli infections)
Why bother with mastitis?
MILK QUANTITY (actual and potential milk)
MILK QUALITY (residues, penalty for high SCC)
Average cost per mastitis case?
£100 per year +/-
What is needed for clinical mastitis?
Pathogen exposure, entry into teat and mammary gland, establishment of infection.
True/false - in mastitis there are always changes in the milk
True (colour, spots, clots etc)
How is clinical mastitis graded?
Describe grade 1 mastitis
milk change only, decreased milk yield
Describe grade 2 mastitis
Subdivided into acute and chronic
ACUTE = milk changes, changes in the udder, milk yield decreased
CHRONIC = as acute but persistent changes (udder and milk)
Describe grade 3 mastitis
As grade 2 but a systemic sick cow (typically E.coli or S.aureus)
Pathogens involved in acute/clinical mastitis - 6
(S. agalactiae) - subclinical
S. dysglacactiae (teat injury)
S. uberis (envi)
S. aureus (contagious)
Exotic agents: Klebsiella, Salmonella, yeasts, Bacillus cereus, Mycoplasma.
Will you have a positive California Milk Test (CMT) with subclinical mastitis?
How would you perform a CMT (OSCE!!!)?
wear gloves (show best practice)
strip pre-milk (highest SCC)
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)
Pathogens implicated in chornic/sub-clinical mastitis
What are the important aspects of mastitis history?
duration, development, stage of lactation and gestation, age, treatment and its response, previous episodes, SCC data from NMR, other cases in herd?? records?
What are the important aspects of mastitis clinical exam?
systemic clinical exam
udder exam (inspect, palpate, LNs)
Milk sample - CMT
Preliminary Dx and Tx
Is Baytri a systemic treatment?
What features do ABs need to have for mastitis treatment? 3
intramammmary during lactation
intrammammary in a dry cow
ABOVE TWO ARE DIFFERENT, DO NOT CONFUSE!!!
What does AB choice depend on?
sensitivity, pharmacokinetics, availability, costs, herd history, withdrawal time
Other treatment options for mastitis - 5
Oxytocin - helps milk letdown which is important to encourage in mastitis cases
Corticosteroids - controversial
fluid therapy -esp toxic mastitis
Why do a culture?
You can never tell on basis of clinical presentation (remember you can use a PCR to determine specific pathogen)
Select your samples (recurrent, persistent, risein SCC)
When should you freeze sample?
Always (in case of treatment failure)
What are the different milk samples that can be taken? 3
Bulk tank sample
Pooled sample of one cow
Individual quarter sample