Toxocariasis is caused by worms found in some dog, cat and fox poo.

Animals with these worms in their digestive system can pass out worm eggs in their poo. You can become infected if poo, soil or sand containing these eggs gets in your mouth.

Toxocariasis is not caught from fresh poo. It's usually caught from soil or sand that has contained worm eggs for a few weeks or months.

Toxocariasis cannot be spread between people.

Most people who swallow the worm eggs that cause toxocariasis do not become ill.

The eggs can hatch into larvae (this is the stage before they become worms). The larvae can spread to parts of the body such as the liver, lungs or eyes, where they usually die without causing any problems.

But rarely, the larvae can cause serious problems like difficulty breathing or loss of vision.

Toxocariasis only causes symptoms if the worm eggs hatch and the larvae spread in your body.

Depending on where the larvae spread, symptoms can include:

• a high temperature
• coughing or wheezing
• stomach ache
• an itchy rash
• eye pain or redness
• changes to your sight, such as seeing small dots or lines (floaters) or flashes of light
• loss of vision (usually in 1 eye)

Worms in your poo

If you have small, white worms in your poo, it's likely to be threadworms.

Ask for an urgent GP appointment or get help from NHS 111 if:

Toxocariasis only needs to be treated if it causes symptoms.

The main treatment is medicine to kill the worm larvae.

If the larvae spread to your eye, steroid medicine may be used to help stop damage to your eye. Sometimes you may also need surgery to remove the larvae or treat any problems with your vision.

Although toxocariasis is rare, there are some simple things you can do to reduce the risk of getting it and help stop pets spreading it.