| Breed | 
  Stress Level | 
  Number of Horses Sampled  | 
  Age Range in years | 
  Average X 106 Cells per ml | 
  Standard Deviation | 
    
   
  | Danish Oldenburg | 
  Low | 
  1 | 
  n/a | 
  ? | 
  n/a | 
    
   
  | Standard bred | 
  Low | 
  1 | 
  20  | 
  63.50 | 
  n/a | 
    
   
  | Standard bred | 
  High | 
  2 | 
  12 –14 | 
  18.17 | 
  n/a | 
    
   
  | Quarter Horse | 
  Low | 
  2 | 
  16 – 20 | 
  8.33 | 
  n/a | 
    
   
  | Quarter Horse | 
  High | 
  4 | 
  5 – 16 | 
  21.45 | 
  2.97 | 
    
   |