Roundworms
are generally cylindrical in shape, tapering at either end.
The life cycle of the roundworm involves four larval moults,
with the stages known as L1, L2, L3, L4 and L5 (immature adult
worms).
The table below includes a brief description
of each parasite along with the location they are found in
your horse. Click on the link to find more detailed information
on that species.
Please note, confirmation of worm species
can only be obtained by a specific veterinary examination.
| Type of Roundworm |
Description |
Location |
| Small Redworm more>> |
Thin and reddish in colour and
up to 2.5cm long. |
Large intestine. Larvae burrow
into gut wall and re-emergence can be fatal. |
| Large Redworm more>> |
Darker red than the small redworm
and up to 5cm long. |
Larvae migrate in horses’
blood vessels. Adults in large intestine. |
| Pinworm more>> |
Pinworms can be up to 10cm
and are white in colour. |
Live in colon. Adults migrate
to rectum to lay eggs. |
| Large Roundworm more>> |
The large roundworm can be
up to 40cm in length and is white in colour. |
Larvae migrate through horse’s
bloodstream to the liver and lungs. Adults in small intestine. |
| Hairworm more>> |
The hairworm is very fine and
hair-like and is only up to 7mm long. |
Stomach. |
| Stomach Worm more>> |
Stomach worms are small, long
and slender and 1-2.5cm long. |
Stomach. Larvae in skin wounds
prevent healing: ‘summer sores’. |
| Intestinal Threadworm more>> |
The intestinal threadworm is
slender and hair-like and up to 1cm long. |
Larvae migrate via lungs. Adults
in small intestine. |
| Neck Threadworm more>> |
The neck threadworm is long
and slender, and about 6cm in length. |
Skin. |
| Lungworm more>> |
Lungworms are slender thread-like
worms and up to 8cm in length. |
Lungs. |
|
