Got to agree with most of the folks here......LA200 and the rest of the 'cycelines' are not longer considered the first choice for most of any illnesses, except maybe as a prophylactic (spelling) treatment. And certainly 2cc of the stuff would do little or no good for any sized calf or cow.
Keep in mind that treating "just a little" is often worse then not at all. As they tend to get a bounce back illness that is now likely resistant to treatment with the previous drug, just as humans are.
When ever treating for any illness, treat quickly and agressively, and for the full time period that is suggested either by yr vet or the drug instructions. NEVER less then that. Re-occurence if often much worse and harder to treat then the initial illness.
Also, keep in mind with respiratory illnesses, this is especially important, as they can become chronic, and often from "silent" pnuemonia that will effect the thrift of the animal as well as continue to shed the same bacteria or virus to others.
You can often find this chronic symptoms among animals that have suffered long term, by the odd breathing, especially after they excite themselves. often coughing eccessively, as the lung walls are scarred, and often entire sections are blocked and no longer usuable. These should be culled if at all possible.
Good luck! :cboy: