Clinical Mastitis Flashcards
What determines whether a case of mastitis will have a clinical or subclinical presentation?
Host-pathogen interaction
When might mastitis occur?
Dry period infection (<30d post calving)
Lactation infection
What do these suggest in terms of SCC before and after calving?
- Low to low
- Low to high
- High to low
- High to high
- Good
- Bad - dry period infection
- Good - successful treatment
- Bad - unsuccessful treatment or disease contracted during dry period.
Is a clinical presentation more likely in contagious or environmental mastitis?
Environmental
How can you distinguish between contagious and environmental mastitis?
- Clinical signs (contagious more likely to be SC)
2. Look at genetics
Why is mastitis a problem?
LOSSES!
- Quantity of milk
- Quality of milk
Loss of around £100/case
How does clinical mastitis occur?
- Exposure to pathogen
- Entry into teat and mammary tissue
- Establishment of infection
- Always changes in milk with clinical mastitis
- Sometimes other signs
What increases chance of infection in terms of mammary gland?
Prolapsed teat canal
What is grade 1 clinical mastitis?
Milk change only i.e. decreased milk yield
What is grade 2 (acute) clinical mastitis?
Milk changes (Decreased yield) Changes in udder e.g. swelling
What is grade 2 (chronic) clinical mastitis?
Milk changes
Persistent changes in udder (Atrophy)
What is grade 3 clinical mastitis?
Milk changes
Persistent changes in udder
Systemic disease
TOXIC mastitis -> e. coli or staph aureus
What organisms cause acute/clinical mastitis?
Strep dysgalactiae Strep uberis Staph aureus E coli Strep agalactiae (subclinical) Exotics: - Klebsiella - Salmonella - Yeasts - Bacillus cereus - Mycoplasma
How is subclinical mastitis characterised?
No visual milk changes
Elevation of SCC
+ve CMT
Reduced milk yield
How do you carry out a CMT?
- Wipe teat
- Pre-strip milk
- Sample milk
- Look at milk (any abnormalities)
- Add reagent and swirl for -1min
- Assess
How can you use electrical conductivity to look for subclinical mastitis? Pros/cons?
Inflammatory process changes ion concentration of milk
Measures ion concentration
Inexpensive and simple
Affected by sample time, milk viscosity, temp and sensor calibration
How can you use in line SCC analysis to look for subclinical mastitis?
Measures ATP levels (inc = increased SCC) Sensor connected to milk host Reagent assette attached below display You can test the milk whenever you want Costly
How can you use spectroscopy to look for subclinical mastitis?
Test for fat, protein, lactose, SCC, urea, LDH
Indirect identification through milk changes
What organisms cause subclinical mastitis?
Staph aureus
Strep uberis
Step agalactiae
Corynebacterium bovis
What history do you need to take for a mastitis case?
Duration Development Stage of lactation Age Treatment Previous episodes SCC data Other cases in herd Records
What clinical exam would you do for a mastitis case?
Systemic exam Udder exam - Inspection - Palpation - LNs Milk exam Milk sample Prelimnary diagnose and treat
How can you treat mastitis?
Antibiotics - Systemic - Intramammary during lactation - Intramammary during dry period Oxytocin NSAIDs Corticosteriods Fluid therapy Calcium Dextros Frequent milking
Why do you need to culture a milk sample?
Can never tell based on clinical presentation the bugs
AB sensitivity
Which animals would you pick for a milk sample?
Recurrent cases
Persistent infections
High SCC
Where can you take milk samples from?
Bulk tank sample
Pooled sample of one cow
Individual quarter sample
How would you take a milk sample from a quarter?
- Cleanse udder
- Swab teat end
- 2 pre strips
- 2 ml in sterile container
- Label name, cow number and quarter
What is the difference between CMT and culture in terms of technique?
Culture milk sample needs to be sterile, whereas CMT doesn’t.
