6.2.2: Individual treatment of mastitis Flashcards
How can we detect abnormal milk?
- Clinical exam/foremilking - legal requirement but does not happen in practice - look for clots, consistency, colour
- Conductivity - this changes with inflammation - high tech parlours
- California Milk Test - detects elevation in SCC over 400,000 cells -> useful for subclinical mastitis
- Individual cow somatic cell counts (ICSCC) - useful for subclinical cases - most UK farms submit figures every month
Differentiate between subclinical and clinical mastitis
Subclinical: can only be diagnosed by milk sampling and sending samples to lab. Not all cows with subclinical mastitis will develop clinical mastitis; some rumble on subclinically for months.
Clinical mastitis can be detected by the farmer during milking.
How should we deliver antibiotics for mastitis - intramammary or systemically?
- Intramammary - you are dosing the udder rather than the cow entire cow so the cure rate is better
- There is no different in cure rate systemic vs intrammary
What would be your antibiotic choice for mastitis and how long would you continue this for?
- Antibiotic tubes may be narrow spectrum (penicillin only) or broad spectrum
- Treat for minimum of 3 days
- Extended treatment 5-8 days (e.g. for Staph aureus infections) can improve cure rate BUT is off datasheet so could have an impact on withdrawals
True/false: resistance to antibiotics is a major reason why many cases of mastitis fail to cure.
False
Resistance to antibiotics is not a feature of the majority of mastitis infections.
What treatment would you consider for cases of mastitis in this herd?
What treatment would you consider for cases of mastitis in this herd? They are a low cell count herd.
True/false: NSAIDs can reduce the inflammatory response necessary to cure mastitis so should be avoided in clinical cases.
False!!!
Mastitis is painful and cows are stoic. Give her NSAIDs!
Describe the aseptic infusion technique needed for intra-mammary antibiotics or dry cow therapy
What is your plan for these cows?
- This cow is unlikely to spread to other cows in the herd unless suspicious of contagious pathogen
- Wait unti dry cow therapy at the end of lactation if possible as this is when we will have the best chance of cure
You have decided to treat a high SCC cow. How will you go about this?
- Identify quarter affected -> extended courses of intra-mammary tubes (7-8 days)
- Consider drying off the quarter
- Consider drying her offf early if she is quite late in lactation
- Cull cows if very chronic infection
What do you need to know in order to prescribe dry cow therapy (DCT)?
- Need to know prevalence of high/low SCC, subclinical infections
- Any bateriology e.g. high SCC with Staph aureus -> may need to be more aggressive
- Individual cow -> what is her SCC history?
- Take a cow-level decision in context of herd factors
What is a sensible cut-off SCC for differentiating infected from uninfected cows?
~200,000 cells/ml
In a high SCC herd where we are suspicious of contagious spread -> may move the threshold to 150,000 cells/ml
How could you define an uninfected cow in turns of cells/ml and clinical mastitis cases?
<200,000 cells/ml for the last 3 milk recordings and no clinical cases of mastitis in the last 3 months.
How could you define an infected cow in terms of cells/ml and clinical mastitis cases?
> 200,000 cells/ml at one or more of the last 3 milk recordings and/or clinical mastitis within the last 3 months.
True/false: cows identified as uninfected should be given antibiotics at drying off to prevent new infection just in case.
False
Uninfected cows should not be receiving antibiotics!
They only need teat sealant.
True/false: all cows need teat sealant at drying off.
True
Some also need antibiotics if infected.
Treatment for uninfected cows?
Treatment for infected cows?
Causative agent(s) of summer mastitis complex
Complex aetiology involving Trueperella pyogenes, Peptococcus indolicus, Streptococcus dysgalactiae
Spread by flies
Presentation and clinical signs of summer mastitis
- Hot hard swollen painful quarter
- Very painful
- Characteristic foul smell
- Cow often lame
- Often goes undetected e.g. in heifers grazing far from the farm
- Can lead to abortion
- Disease of dry cows and heifers; can affect young calves, and even bulls and steers
Treatment and prognosis for summer mastitis
- Intramammary antibiotics are useless -> need systemic penicillin or derivatives
- Regular strip quarter
- May need to institute dranage by removing teat/opening up vertically -> pus is very thick
- Generally lose the affected quarter even if detected and treated
Control of summer mastitis
- Fly avoidance (specific pastures)
- Fly control (spray, pour-ons)
- Dry cow therapy -> repeat infusions
- Teat sealants
- Stockholm Tar, micropore tape etc.
- Certain pastures may be best avoided for warmer months of years e.g. avoid those with bogs and ditches that might promote flies
