How often should a fecal test be done on a healthy horse?

A.  This depends on the age and condition of the horse as well as prior fecal results.  Older horses generally have fewer issues due to a natural worm resistance that has developed over time.  Young horses, especially those under three years of age, need more frequent testing.  As a rule of thumb, many equine veterinarian suggest fecals be done at least four times a year for adult horses.  If a horse is under three years of age, every other month is best.  This schedule should be followed until there are few to no parasites seen on a few consecutive samples.  Then the time between samples can be increased.