@ccr the only reason to think she might get it again is if you keep her and she does get it again. One of the biggest problems in the past several years has been flies that seem to land on the udders of heifers and they carry germs that will seem to get into the teats when the flies are biting the cattle, and the udders are a favorite place for these flies; and cause mastitis or even dead quarters. Have had several dairyman talking about the 3 ":teat" heifers come in milking after a bad fly year.
I won't cull a cow for mastitis in one quarter if she gets over it. But, if she is one that likes to lay in a muddy spot or manure and gets it again, then it is a strike. A cow can raise a good calf on 3 quarters if she milks decent.... Often the mastitis will seem to make them "light " in that quarter subsequent years....
All according to what type of mastitis, will determine the best treatment. Excenel is good because it has next to no withdrawal...shots that get into the whole body...... using a tube treatment in the quarter will determine withdrawal for selling... and it is impossible for it to stay in there long if the calf is nursing so a shot of some sort is better.
If it is watery, then either coliform or klebsiella.... and they require some heavy duty treatment and fast... klebsiella can kill a cow in 24 hours.... if you save her then she usually dries up. Coliform is serious also, although won't kill them quite as quick.... IV treatment for both is usually indicated.
If it is just a staph or strep then using an oxytet sometimes will help but Excenel is my preference.... If they are running a fever it is more likely a coliform.... klebsiella will make them go sub temp.....
Neither klebsiella nor coliform are that common in beef, but coliform does show occasionally. Klebsiella is usually always from using sawdust that is not dried or "heated".... from soil organisms that get embedded in the bark of oak trees mostly....and then made into sawdust at a lumber mill.... coliform is environmental and can come from an extremely wet area....