Mastitis: Therapies Flashcards
Why is dry cow therapy used?
Clear persistent infections
* Sub clinical
* Staph-aureus- intracellular
* High cell counts
Protect against new infections
* Acute E coli
* Summer mastitis
What pathogen causes summer mastitis with:
1. Necrosis
2. Foul smell
How is summer mastitis managed?
- Arcanobacter pyogenes
- Peptococcus indolicus
Pyrethrin pour on- flies
What are the disadvantages of dry cow therapy?
- Lower cell count
- New infections from poor hygiene
- Spectrum required to protect against enterobacteriaecae
- Cost
- Consumer pressure
- Farm assurance schemes
What is selective dry cow therapy?
- Teat sealant only to some cows
- Used with AB tubes based of bulk milk, mastitis incidence, outbreak type
What are teat sealants made from?
How do they work?
4g suspension containing 65% bismuth subnitrate
Remains as a paste within the base of the teat cistern and teat canal until stripped at calving
What cows should be selected for selective dry cow therapy?
SCC
* > 200,000
* > 125,000- first lactation
* Clinical case
* CaliMT before drying off
* Check teat ends- damaged AB?
What are the problems with teat sealants?
Black spots in cheese
* Bismuth subnitrate and hydrogen sulphide
Risk of infection with poor hygiene
Describe intra-mammary tube application
- After milking and cleaning of parlour
- Clean gloves
- Pre-dip- 30s
- Surgical spirit and cotton wool
- Clean teat end until no more dirt
- Insert and deposit
- Post dip- some repeat sailt
- Loafing 30min
- Feed restriction- reduce milk production
How is formulation of AB dry tubes varied?
What difference does it make?
- Type of AB
- Salt of AB
- Particle size
- Short duration- short dry period or repeat treatments
- Standard
- Extended protection
How should AB tubes be selected?
What are common combinations of ABs?
Target staph then broaden out
- Cloxacillin ± Ampicillin
- Penicillin ± framycetin ± penethamate,
- Cephalosporins- critically important (C&S)
What are the milk times after calving of AB dry cow tubes?
- Usually 96h post calving
- Some 156
- Some 24
Influence of other conditions- milking frequency, milk fever
What other treatments can cow recieve at drying off?
Other then mammary tubes
- Tylosin
- Tilmicosin
Authorised for pneumonia in beef
* Draxxin
* Zactran
* Zuprevo
Why do not all mastitis cases need treating?
- Culture negative
- Yeast
- Self cure
What can cause mastitis treatment failure?
- AB resistance
- Bacterial dormancy (treatment duration- 10 life cycles)
- L-forms
- Biofilms
- Reduced host response- steroids, stress
- Reduced phagocytosis
- Re-infections
- ABs problem- too low, too long dose interval, too short tx period
- Pharmacokinetic limitations- absorption, disposition, elimination
Does E.coli need AB therapy?
Likely to be self-resolving
What are the best ABs for Gram +ve (S. aureus, Streps)
- Penicillin G
- Streptomycin
- Pot Amoxycillin
- Cloxacillin
- Macrolides
- Cephalosporins
- Pot Sulphonamide
What are the best ABs for gram -ve?
- Streptomycin
- Pot Amoxycillin
- Pot sulphonamide
- Tetracycline
- Neomycin
What combinations of ABs can broaded spectrum?
Lincomycin and Neomycin
Combinations can also reduce resistance
Penicillin, novobiocin
What antibiotics gets to infection well via teat?
- Macrolides
- Phenicols
- Fluoroquinolones
- Penethamate
- Aminopenicillins
- Novobiocin
- Trimethroprim
What ABs have good delivery to mastitis via blood?
- Macrolides
- Phenicol
- Tetracyclines
- Fluoroquinolones
- Trimethroprim
What is typical milking cow therapy for mastitis with ABs?
Typically
* 12hr intervals
* 3 consecutive milkings
* or every 24hr 3 times
* Need 8d tx for 95% biological cure
What extra treatments should be considered?
- Oxytocin
- Adequate vit E/selenium
- Copper
- Zinc- teat keratin
- Startvac- inactivated E.coli/ staph aureus
- UBAC- strep uberis
- Pain relief- NSAIDs
What is licensed for intramammary and systemic?
Cobactan
Synulox
What are good cases for selection?
Young first case this lactation- high SCC last month
* IM
End of lactation, high SCC
* dry off and treat
Old and 3rd case- chronic high SCC
* cull
Young, first case, low SCC previous months
* No treatment
What is velactis?
D2 dopamine receptor agonists inbition of prolactin secretion
* In aid of abrupt drying off
What is imrestor?
Cytoline bovine granulocyte colony stimulating factor
* restored normal neutrophil function to cattle during PPP
* Reduced susceptibility to clinical mastitis infections
Withdrawn from market- metritis
