The adult worming routine is not suitable for horses under the age of five. Foals and youngsters up to four years need more careful monitoring because their natural immunity to worms has not yet had time to develop. We strongly advise that owners of young horses contact Tower Equine for advice, as this can vary depending on individual premises. However, a basic guide is as follows:

From foal to one year old

  • Do not start worming until the foal is two months of age.
  • Then start with a single dose of fenbendazole (Panacur) as a roundworm treatment. Repeat this every six weeks up to the age of six months.
  • Perform a WEC at 3 and 6 months of age.
  • Give a single dose of a combined wormer in the December of the foal’s first year.
  • Your vet will advise you what is appropriate


  • Treat pregnant mares as normal adult horses with a 3 x yearly WEC and a single dose of wormer in December.
  • In addition, give a dose of an ivermectin based wormer just before foaling.
  • Do not worm in the two weeks after the mare has foaled.
  • Continue with WECs as normal after foaling.

Yearlings to 4-year-olds

  • WEC every three months with worming where indicated and a post-worming WEC to check effectiveness of any treatment.
  • Treat every six months with a wormer with combined effect against cyathostomin and tapeworms.
  • An optional third treatment in mid-summer using a different wormer if stocking levels are high.
  • Manage pasture effectively, ideally with a system of rotation and resting. In particular, ensure that yearlings do not graze the same fields in successive summers.