Sheep, goats, cattle and pigs all carry worms. A low burden is normal and most animals cope, but heavy burdens cause poor growth, scouring, anaemia and losses, so it pays to know what is in your stock before you treat.
The main parasite eggs found on a livestock worm egg count. Illustrations, not to scale. Coccidia are not worms, but their oocysts are also seen on the test.
Sheep and goats
The roundworms that matter most are the stomach and gut worms, Teladorsagia (brown stomach worm), Trichostrongylus and the blood-feeding barber's pole worm, Haemonchus, which causes anaemia and a swollen jaw ("bottle jaw"). Their eggs look alike on a standard count, so they are reported together as roundworm (strongyle) eggs. In young lambs and kids, Nematodirus has distinctive large eggs and can cause serious illness in spring. Lambs can also carry Moniezia tapeworm and coccidia.
Cattle
Cattle carry Ostertagia, Cooperia and related roundworms, mostly a problem in calves in their first grazing season. Adult cattle build up immunity, so lower counts are usual. Calves can also carry coccidia and tapeworm.
Pigs
Pig worms include the large roundworm Ascaris suum, the whipworm Trichuris suis, nodular worm (Oesophagostomum) and Strongyloides. They are most common in outdoor and organic units and in pigs kept on the same ground. Young piglets can also carry coccidia. Pigs are not affected by liver fluke.
Tapeworm
Lambs and calves pick up Moniezia tapeworm from mites on pasture. Tapeworm is rarely a serious problem, and egg packets are shed intermittently, so they are easily missed on a single sample.
Coccidia (Eimeria)
Coccidia are microscopic gut parasites, not worms. Young animals pass tiny oocysts in their faeces, and these float in the same solution as worm eggs, so we report them on the same test. Most young stock carry a few. Higher numbers matter most in lambs, kids, calves and piglets that are scouring or growing poorly.
Fluke and lungworm
Liver fluke, rumen fluke and lungworm need different tests. See our guide to liver fluke, rumen fluke and lungworm.
What the test does not cover
The worm egg count looks for worm eggs and coccidial oocysts. It does not test for lice, mites, ticks or bacterial and viral disease. If animals are unwell, speak to your vet.
Ready to test?
Collect fresh faeces at home, post them free to our laboratory (Monday to Wednesday) and your result appears in your account within 24 to 48 hours of the lab receiving your sample.
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This page is general information, not veterinary advice. If your animals are unwell, or you are unsure what to do, speak to your vet.