Manure from an eighteen month old foal who had been wormed
The large white worm is an Ascarid and female worms can lay as many as a
million eggs each day. They can survive for years on pasture and in
stables. Foals develop immunity at about 18 months of age.
The other red larvae seen are bot fly larvae. Eggs are laid on the legs and
face of the horse which hatch into maggot-like larvae before entering the
horses’ mouth. When the larvae are attached to the stomach wall they can cause
inflammation and ulceration. Large numbers can obstruct the exit from the
stomach, causing colic and perforate the stomach causing fatal peritonitis.
Other worms found in this small foal were both red and white strongyles.
These can cause severe diarrhoea, rapid weight-loss, colic and sometimes death
of the affected animal within a very short period of time.
A local vet has a piece of gut completely closed by worm damage that killed
a two year-old racehorse.
Parasitic worms are a threat to horses and ponies of any age. Foals can even
become infected with worms from their mother’s milk and horses at grass will
be exposed to infection from a wide range of parasites.
It is essential to worm your horse or pony regularly. An easy way of remembering
to worm is to do it when the farrier comes to trim or shoe your horse or pony
(about every eight weeks). Check the wormer packet for more specific guides.