In September 2017, I wrote an article about Herz a horse owned by Ginger Krantz that over the years had very few positive fecal egg counts even though the owner had only dewormed him 9 times in 24 years. Today I would like to compare Herz’s results with another horse, Tristan, who is owned by Rene Stone. Tristan appears to be on the opposite end of the spectrum so to speak. The chart below compares the test results of Herz and Tristan over the years. Horsemen’s Laboratory has evaluated their worm control through doing fecal egg counts. Both horses live in New Jersey and are roughly the same age. Both owners routinely sent in samples from their horses approximately every 3 months.
Ginger only dewormed Herz when he had a positive sample. Horsemen’s Laboratory examined 63 samples from 1993-2017 with only 9 of those samples being positive. From 4/8/96 to 11/15/06, 25 samples were examined without having a positive sample. Tristan was also dewormed after every positive sample and over the 7 years 65% of his samples were positive. This dramatically demonstrates the difference between a high shedder and a low shedder. Tristan often had over 1000 strongyle eggs/gm, while Herz never had over 50 strongyle egg/gm.
Horsemen’s Laboratory recommends doing at least 4 samples over the course of one year to establish if a horse is likely to be a low, medium, or high shedder.
The chart below shows how horses kept in similar conditions, of approximately the same age, in the same area of the country can have widely different medical histories concerning their worm infections. The chart and the pictures also once again proves it is impossible to know a horse has a problem with worms by just looking at them.
| HORSE | #FEC | #NEG | #POS | #LOW | #MED | #HIGH | #˃1000 | YRS TESTED | AGE |
| Tristan* | 40 | 14 | 26 | 4 | 5 | 17 | 6 | 2010-2017 | 28 |
| Percent | 100% | 35% | 65% | 45%* | 12.5% | 42.5% | 15% | ||
| Herz | 63 | 54 | 9 | 9 | 0 | 0 | 0 | 1993-2017 | 31 |
| Percent | 100% | 85% | 14% | 100%* | 0% | 0% | 0% |
#FEC (fecal egg count)
#Neg (number of samples where no eggs were found on counting chamber)
#Pos (number of samples where eggs were found on counting chamber)
#Low (number of samples indicating low shedder 50-200 eggs/gm)
*When figuring low shedder percentage negative samples are included in low category
#Med (number of samples indicating medium shedder 200-500eggs/gm)
#High (number of samples indicating high shedder 500 + eggs/gm)
#>1000 (number of times eggs found on counting chamber indicated count was more than 1000eggs/gm)
*In all positive samples only strongyle eggs were found
Herz
Tristan
