DEWORMING of horses is an integral part of basic equine husbandry. Foals and weanlings are no different from older horses and establishing an effective deworming practice is vital in giving them the best start in life.

Fenbendazole (e.g. Panacur equine granules or Panacur 10% oral suspension) is recommended for treating foals routinely at three months of age in case of roundworm infection. Roundworms typically affect foals and weanlings, not adult horses.

These are relatively large worms found in the small intestine. They can cause impaction colic, respiratory signs and ill-thrift in young horses.

Threadworms are another type of worm which can affect foals and weanlings, thankfully infections caused by threadworms have become rare. Foals become infected with threadworms through the colostrum or milk of the mare.

CLINICAL SIGNS

Foals less than six months of age are thus typically affected, potentially with clinical signs such as diarrhea, respiratory signs and weight-loss.

Foals acquire immunity by weaning time against this parasite. Hence, it is recommended to only treat foals with clinical signs and allow all others to develop immunity naturally. Historically popular, preventative treatments of pregnant mares and neonatal foals are also no longer recommended.

‘Faecal egg counts’ (FECs) are one of the best ways of determining how often a horse should be wormed. FECs determine the classification of each horse as a ‘low shedder’, a ‘moderate shedder’ or a ‘high shedder’. These classifications are based on the number of worm eggs shed in the faeces of each horse.

An FEC test should be performed at six months of age to determine whether any worms present are predominantly roundworms or small stongyles, and a treatment administered based on these results.

Two further treatments should be administered at nine and 12 months of age, and one of these treatments (usually at nine months to coincide with autumn time) should also target tapeworms.

Doireann Dowling is a veterinary nurse and environmental scientist who is currently completing a Masters in Livestock Health and Production.

She worked in equine practice on the Curragh for five and a half years and has worked in Dundalk Institute of Technology for the last eight years where she lectures on the BSc. In Veterinary Nursing. Dowling has a keen interest in parasitology and is happy to be contacted at doireann.dowling@dkit if you have any queries.