-
how is staph aureus diagnosed?
- Cultures
- -coagulase positive
- -double zone of hemolysis
-
how is staph aureus mastitis treated?
- *Dry therapy + long term IMM Abs*
- Systemic Ceftiofur/cloxacillin
- (Some B- lactam Resistence)
-
how is staph aureus prevented? 4
- separate infected; cull non-responsive cows
- Tx at dry off and teat sealant
- No unpasteurized milk for calves
- Teat Dip at milking
-
Strep. agalactiae is another highly contagious mastitis pathogen. what form does it cause (acute/chronic/subclinical,etc)?
- Subclinical with Peracute local inflammation
- (if bulk tank SCC increases suddenly look for this bacteria!)
-
where is strep ag found?
- only in the mammary gland - multiplies in milk but doesn't go deep
- +/- cistern - fibrosis if chronic
-
how does cow present with typical strep ag mastitis?
Strip cup?
CMT?
- no clinical signs of systemic illness (poss. febrile)
- abnormal strip cup
- positive CMT
-
how is strep ag diagnosed?
- culture via cAMP test;
- cAMP+ (arrow shaped hemolysis) = infection
-
how is strep ag treated?
- Amoxi
- +/-Pen
- early IMM tx successful (systemic usu. not needed)
-
how is strep ag prevented? 4
- proper milking hygiene
- dry cow therapy
- pre/post dipping
- *eradication w/vigilance is possible*
-
what is the less common cause of contagious mastitis that can cause "sandy like" milk secretions that can be watery to purulent?
mycoplasma bovis
-
what are clinical signs associated with mycoplasma bovis?
- Herd c/s:
- Bronchopneumonia
- Otitis
- Polyarthritis
- Mastitis
-
what is a common cause of mycoplasma bovis mastitis flare ups?
Is it safe to feed this milk to calves?
- stress
- No - can spread systemically
-
where can you collect samples to look for mycoplasma bovis?
- mucous membranes and secretions from respiratory and urogenital tracts
- (infection highest in calves and heifers)
-
how is mycoplasma diagnosed?
special media required, would be negative on routine culture
-
how is mycoplasma treated?
- does NOT respond to routine tx - life long carriers - cull
- if choose to tx, need macrolides systemically (no intramammary macrolides exist)
-
what are 5 things that should could happen present on the farm that would lead to to consider mycoplasma bovis outbreak?
- 1- mastitis after pneumonia problems
- 2- calf joint swellings/lameness
- 3- calf head tilt/inner ear infection
- 4- cows with new knee/hock swellings
- 5- multiple quarters non responsive to tx; sandy milk; neg. routine culture
-
what are 2 major environmental pathogens causing mastitis?
- e. coli (poor conditions)
- klebsiella (saw dust shavings)
-
what are 2 minor environmental pathogens causing mastitis?
-
are coliform infections more prevalent when gram positive infections are controlled or when there is an outbreak?
- coliforms more when G+ is controlled
- (low SCC can lead to coliform mastitis)
-
why do coliforms proliferate when SCC are down?
coliforms don't adhere to epithelial cells so when SCC is high, coliforms are quickly eliminated
-
do coliform infections proliferate during milking or dry periods? are they clinical or subclinical?
establish during late dry period (no "flushing effect") - subclinical then flare up after calving/during immunocompromise
-
how does coliform mastitis become endotoxemia?
- multiply then die in gland - release endotoxin from cell wall
- TNF-alpha released by body and triggers cascade - hematogenous spread
-
what are the most important inflammatory cytokines involved in endotoxemia? what is the main problem caused by these mediators?
- IL1, 6 and TNF-alpha
- increased vascular permeability
-
do most cows with coliform mastitis recover spontaneously or die?
- most recover spontaneously w/o treatment
- (unless endotoxemia then death)
-
how does milk appear with coliform mastitis? what will udder look like?
- egg drop soup (serous fluid replaces milk)
- acute swelling of gland
-
why are cows with endotoxemia polyuric?
altered response to ADH so pee alot even though hypovolemic
-
Assuming the cow recovers from coliform mastitis, what is the result to the udder?
- will not be able to milk for remaining lactation but will return to normal after next calving
- good news: environmental/coliform mastitis will NOT cause permanent fibrosis like contagious/staph will
-
are systemic antibiotics indicated for coliform mastitis?
- yes, to prevent pneumonia and endocarditis
- intramammary can be troublesome bc should be stripping udder every 4-6 hours
-
Is the vaccine for coliform mastitis recommended? As prevention or to reduce severity?
- effective to *reduce severity*
- labor intensive, requires multiple injections (3 given 3 weeks apart)
-
what is the most common isolate in heifers and beef cows for mastitis? what is the cause?
- staph aureus - flies transmit
- (gangrenous more in heifers than old)
-
what is most common isolate in small ruminants with mastitis?
- staph aureus - gangrenous
- (suspect mycoplasma mycoides if negative culture)
-
what is cause of hard udder with no change in milk in small ruminants?
- CAE (caprine arthritis encephalitis)
- OPP (ovine progressive pneumonia)
-
what is the cause of mastitis in camelids? why is it more difficult to treat them intramammary?
- rare in camelids
- each quarter has 2 distinct lobes - tom cat catheter
-
what is the problem with udder edema?
- extra weight - pendulous - harder to attach equipment and more prone to trauma
- (milk remains normal; udder should NOT be hot)
-
when is blood in the milk seen but not a problem?
when are we worried about it?
- Pink after calving= No problem
- Bloody= Problem= Severe mastitis
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