Your veterinarian will usually want to re-check your horse within the next few days, depending on how sick your horse is. At this time, he will listen to your horse's lung sounds, to determine if things are improving. He will probably also take another complete blood count, to see if the body's inflammatory response system is responding to the antibiotics.

The results of culture and sensitivity are usually available within 3 to 5 days. There is really no good way to make the results come back any faster – the laboratory is completely dependent upon how fast the bacteria grow in culture. If your horse is doing well, it frequently turns out that the empirical choice of antibiotics was correct. If your horse is not improving, or is not doing as well as you and your veterinarian might like, this is usually the time to change antibiotics.

Your veterinarian will usually continue with a given antibiotic for at least 48 hours before concluding that it is not working.

If your horse's pneumonia was severe enough that it required a visit or a stay at the hospital, you will probably be advised to bring your horse back for re-check x-rays at the time when you will be discontinuing antibiotics. This will enable your veterinarian to determine if there are any small vestiges of disease left.

After your veterinarian has pronounced your horse cured, remember that he has gone through a long and physically exhausting illness. It is important to give him plenty of rest (usually at least one month of pasture rest) before bringing him back into training.

When you do bring your horse back into training, do so gradually and slowly. It will take time to get back to the same level of fitness that he had prior to the pneumonia. Although most horses maintain their level of fitness for 4 to 6 weeks, recovery from pneumonia takes longer, so expect to spend 8 to 12 weeks getting your horse back into top condition.