These are white worms 30 – 60mm found in the blind gut (caecum) of the sheep. They occur in all sheep production areas of Australia.

Find out more about whipworm:

• Life cycle
• Location in the sheep
• Effects on the sheep
• Diagnosing whipworm
• Treatment

 Whipworm life cycle

The female in the blind gut (caecum) lays eggs that pass out in the dung. The larvae develop to 3^rd stage inside the eggshell and remain there until ingested by the sheep. They are very resistant to desiccation and freezing.

When the dung pellet disintegrates, larvae in the eggshell are released into the soil surface. Sheep grazing close to the soil surface ingest the larvae in the eggshell.

The L3 larvae are released from the eggshell and enter the wall of the small intestine and re-emerge in the blind gut (caecum). They attach to the wall of the blind gut, mature and mate and start the cycle again.

 Location of whipworm in the sheep

Whipworms are found in the blind gut (caecum) of the sheep.

 Effect of whipworm on the sheep

Whipworm can be a problem in sheep during drought. Sheep with heavy infections of whipworm are unthrifty, have diarrhoea with mucous and may die.

In sheep with heavy infections of whipworm large numbers of the worms will be visible on the lining of the caecum. The lining of the caecum may be reddened and thickened with ridges. It may also have blood spots and be covered with brown mucus.

Trichuris in the caecum/large bowel of a sheep

Image supplied by Dr R Woodgate, Western Australia Department of Agriculture

 Diagnosing whipworm

Whipworm has a very distinctive egg and is readily identified during worm egg counts.

The worms are also easily identified during post-mortem examination.

 Treatment of whipworm

All broad spectrum, long and short acting drenches are effective against whipworm.