Implementing A Horse Worming ScheduleBy Jeffrey Rolo
It is surprising how many horsemen do not incorporate any form of horse worming schedule in their routine, seemingly just choosing a box of horse wormer at random and thinking that will do the trick. While it is true that there are many fine horse worming products available to horse owners, ultimately if you wish to keep your equine friend as protected against the multitude of parasites just dying to infest your horse you will need to draw out an effective plan of action.
Yes, this means you must incorporate the various forms of horse wormers into an organized horse worming schedule that targets the various parasite groups during the times of year they are most a threat.
As a quick side note, technically the terms we should use are de-worming and de-wormers, but since most horsemen remove the "de" when discussing this topic we will do the same.
Before jumping straight into the actual recommended horse worming schedule I would like to put out this caution: if your horse is already seriously infested with parasites you should be very careful about giving him a dose of paste wormer. A paste horse wormer could conceivably kill too many parasites at once, thereby causing them to bunch up in the horse's veins, intestines and colon. While this can kill a horse, more often then not it will just cause significant discomfort… but do we really want to cause discomfort to our equine friends?
In such cases I would start the worming process with a pellet wormer such as Strongid C2X. Since pellet-based wormers are mixed with a horse's feed daily, the potency is far lower than actual pastes. This lower potency allows for a slower and healthier parasite kill and removal rate. I advise putting a parasite-infested horse on a pellet-based wormer for at least one week before advancing to the standard paste regimen.
You must be careful to apply the recommended dose of horse wormer with each session, because parasites possess the ability to build a resistance towards agents designed to kill them when the agents are not applied in doses strong enough to kill the parasites outright. This is why it is also important to rotate the various types of horse wormers – not only does it increase the spectrum of targeted parasites, it makes it difficult for parasites to build up any sort of resistance or immunity.
Following is a solid horse worming schedule that we recommend:
Please note that Moxidectin is NOT recommended for foals or weak horses since an overdose can be very dangerous to them.
The above horse worming schedule will suit most standard horse needs very well, but if your horse is one that grazes frequently you may want to modify it a bit to include a five-day double-dose schedule of a Fenbendazole-based wormer in October and February. This purges your horse's system of encysted larvae that are picked up easily during regular grazing. Since encysted larvae are very difficult to nail without the use of Moxidectin, the five-day regimen is necessary; you won't be able to purge a horse's system of this parasite with just one or two doses.
Note: Under no circumstance should you provide a double dose of Moxidectin. Although effective against larvae and bots with just one dose, multiple doses can be a danger to your horse.