Small Strongyles

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Small Strongyles
These are a type of nematode worms and in some ways are very similar to that of the large strongyle worm.

Other Names
They are also known as Cyathostomes.

Description
Small strongyle worms are round in circumference and thread like in appearance.

Horses At Risk
All horses at potentially at risk, with very young horses being most at risk. Infection can also occur where there are several horses all over grazing a pasture.

Small Strongyle Infection

A horse who is already infected with small strongyle worms will pass out strongyle eggs in their droppings.
The strongyle eggs then hatch into the infective stage of larvae within one to three weeks depending on the climate conditions.
The eggs can be found in the soil, on blades of grass, water troughs and on dew drops on blades of grass.
The eggs are then swallowed by another horse and start to migrate towards the intestines.
When the larvae enter the large intestine they immediately invade the gut lining which is also called the mucosa.
It is here that scar tissue forms around the larvae protecting the larvae from the horses immune responses and providing it with a safe environment to mature. The horse will suffer very little inflammation of the gut lining from the larvae at this stage.
The egg is now known as encysted stage larvae.
When the larvae are ready to leave the gut lining they mature into adults and begin to lay their own eggs which get passed out with the droppings and begin the cycle again.

Symptoms

Diarrhoea
Weight loss
Anaemia
Colic
Abdominal discomfort
- Inflammation of the gut lining occurs when the cyst ruptures.
- Tissues around the cysts also haemorrhage when the cysts rupture.
Poor or dull coat
Horses are often very lethargic.

Diagnosis
Horses are usually infected with both large and small strongyles and it is only by having a faecal culture done that identification of the larvae will be possible.

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.
Regular pasture maintenance, such as harrowing and removing droppings, will help to reduce the amount of faeces and larvae from the fields, it should be remembered that larvae can last for 1 to 5 weeks and in certain moist conditions for up to 2 years.
Where possible try not to have too many horses overgrazing one area as this increases the amount of droppings and therefore the possibility for re-infection.