Foals are born with little immunity to parasites, this develops as they get older. High burdens can affect growth and result in life threatening conditions. Owners often struggle when choosing a correct and “safe” wormer for pregnant and new born foals.
There are a number of parasites that commonly affect foals;
Strongyloid Westeri (intestinal Threadworm)
A roundworm that can be transmitted through the mammary gland to the foal causing chronic diarrhoea and poor growth.
Treatment/ Prevention: Treating the mare with moxidectin four weeks before the due date or ivermectin before foaling.
Ascarid (Parascaris Equorum)
Roundworm that can grow up to 40cm in length and reproduce in large numbers. A dullness in coat, “pot belly” or poor weight gain are signs to look out for. Large burdens can form intestinal blockages resulting in colic or pulmonary haemorrhages from migrating larvae.
Treatment/ Prevention: Treating the foal with fenbendazole when one month of age and then every 4-6 weeks until 6 months old.
Due to the lower immune system found in foals, higher burdens are common. A burden can result in weight loss, inflammation or colic.
Treatment/ Prevention: Treatment with ivermectin or moxidectin chemicals, along with frequent worm egg counts.
Guide to Worming a Foal