Neck Threadworms

See also: Horse Wormers (Manufacturers) | Horse Wormer (Chemicals) | Horse Worming Schedule

Neck Threadworms
Neck Threadworms have an indirect life cycle and require quick and aggressive treatment which your vet will advise you on.

Other Names
Neck Threadworms are also known as Onchocerca. Microfilariae is the name given to the larvae stage.

Description
They are long and coiled in shape with the males being around 7cm in length and females being around 30cm in length.

Threadworm Infection

Threadworms have to depend on another organism to get it to the horse.
The neck threadworm microfilariae live in the tissue just under the horse's skin and wait to picked up by a biting midge.
Once inside the midge they develop to the infective larvae stage within approximately 3 weeks.
Once at the infective stage, when the midge bites another horse the neck threadworms are able to enter the horses system via the midges bite.
The Threadworms then travel to the ligaments in the horses neck and also to the flexor tendons and suspensory ligaments.
Threadworms are transmitted by a biting midge, often of the Ceiatopogonidae family.
Once the Threadworms have reached the horse they travel to the connective tissue around the head, neck and underbelly of the horses body.

Horses At Risk
All horses are potentially at risk.

Symptoms

Sores along the topline
Sores along the stomach
Sores, irritation and swelling around the eyes
Uveitis - This occurs when there are large quantities of dead microfilariae in the eye which causes the dead to give off large amounts of antigens which cause inflammation in the eye.
A constant water stream out of the eye or eyes often along with a white or yellow mucous in the eye on a regular basis.
Hair loss around the head and neck area.
Swelling around Ligaments.
Swelling around tendons.
Lameness.
Lumps under the horses skin on the ligaments.
Blindness can occur if the infection around the eye is severe or if treatment is delayed.

Prevention

The use of worming products is essential to help protect your horse, ask your veterinarian for a worming schedule to help protect your horse from the threat of these and other worms.
If you suspect Threadworm consult your vet immediately to discuss treatment.
Maintain good pasture management.