AThere are three related issues here–recovery of the affected horse, how soon the affected horse can return to his normal routine, and the possibility of spreading the disease to other horses.

Our rule of thumb for flu-like illnesses is that for each day of fever, the affected horse should be stall-rested for one week. So if the fever takes three days to break, the horse should be stall-rested for three weeks. But that does not mean the horse should be cooped up in his stall for the entire period. If the horse’s temperature has returned to normal and any lethargy has gone, he will probably recover faster if turned outside daily for a couple of hours of fresh air and purely casual activity, e.g., grazing in a small paddock. But no work! Avoid stresses from weather or other horses. Also, the stall where the horse is housed should be well-ventilated.

How soon can the horse return to his normal routine? Following the period of stall rest, the horse should be gradually returned to a normal work or performance routine over a period of one to four weeks, with the trainer and veterinarian closely monitoring how well the horse is responding and being alert to any arising complications. Remember that in a case of flu, it can take three weeks for the lining of the horse’s respiratory tract to fully recover its normal function of keeping dust and germs out of the lungs. Also, complications like pleuropneumonia can take longer to clear up