Why I Use Chemical Wormers Encysted Strongyles

By Cynthia Coope

I would love to be able to worm my horses more naturally, and years ago I tried it that way, but their health was suffering due to the following issues:

Property too small for the number of horses (15 on less than 40 acres).Not enough help/time to pick up poo regularly and land too steep for manure vacuum cleaners!Not enough paddocks to rotate around to let them rest for long enough.Neighbours who don’t worm their horses for bots and so my horses get infected too.A wet climate which allows worms to spread easily (they travel in water and along grass that is covered in water droplets).Breeding young horses who are more susceptible to worm infestation so they need treatment more regularly until around 3 yrs.Natural wormers don’t really work as my faecal egg counts showed.Previous problems with colic symptoms in various horses which I couldn’t attribute to anything else, and which resolved upon worming.

Since reading Ann Nyland’s book – ‘What You Don’t Know About Worms Will Surprise You’, I’ve come to realise that perhaps the only way you can get around using less chemical wormers is to have the opposite of all the situations I listed above, and/or use along-acting wormer like Equest which suggests 14-16 weeks between treatments.

Also, some horses are more likely to have a better immunity to worms so if you only had a couple of horses who lived together on a largish acreage then you might get away with worming naturally, picking up all manure and keeping a check on their egg counts.

However, faecal egg counts won’t tell you if they have tapeworms or encysted strongyles that can stay in the gut wall for years, just waiting for the right conditions to hatch.

Encysted strongyles are one of the leading causes of worm related deaths (most present with colic symptoms or severe and prolonged diarrhea, and sadly, many people aren’t aware of this.

In a recent poll on worming, from a total of 280 votes – it looks like less than half the voters knew what to treat encysted strongyles with (Moxidectin or Fenbendazole).

Results of the Poll by The Horse.com

Which of the following de-wormers do you use to treat encysted small strongyles?

 Ivermectin: 35.57% (164) Moxidectin (e.g., Quest): 25.60% (118) Pyrantel Pamoate (e.g., Strongid): 19.09% (88) Fenbendazole (e.g., Panacur): 15.84% (73) Other: 3.90% (18)

Ivermectin will not touch encysted strongyles and there seems to be more brands of wormer these days that contain Ivermectin (+ other chemicals) than there are alternatives.