When the same worm egg count result can mean something completely different

This week a racing trainer, who has incorporated a parasite risk intelligence programme at their yard to try to remove some inconsistencies in performance, received some worm egg count results from their vet.

As standard with vet results it included advice on whether to treat or not to treat.  There were two horses with the same result 250epg and the vet recommended to treat Horse A and not to treat Horse B.

These recommendations were based only on the results and did not take any other factors into account.

Horse A has not been wormed for six month and had a low Small Redworm Blood Test 3 months previously [carried out by the vet!].  It has not been on any pasture since.  250epg is a low medium reading and there were no clinical symptoms at all.

Taking a complete parasite risk intelligence approach Horse A would not receive a wormer, but instead it would be retested in 8 weeks time to assess whether the shedding activity is static, increasing or decreasing which would provide an enormous amount of additional information. 

Horse B was wormed 12 weeks ago with an Equest wormer.  It also had a high Small Redworm Blood Test 3 months previously [carried out by the vet].  The result of 250epg indicates a much higher level of underlying larvae as the effective period of moxidectin is 13 weeks.

This horse does require worming in order to prevent a huge increase in shedding once the tail effects of the moxidectin wears off.

The vets advice of not worming this horse and to test in 13 weeks could potentially have a negative impact on its health and its performance.

This really does highlight the difference between making decisions on only one aspect of parasite risk, which is something that occurs in only 95% of cases.  Remember parasite risk intelligence is more that a single number.