• Bom Harris, DVM

Managing Internal Parasites in Sheep and Goats


Barberpole worm and other internal parasites have been deadly in sheep and goats this year. While mature cattle generally develop good immunity to internal parasites, small ruminants remain susceptible throughout life. They are especially susceptible to the barberpole worm, which causes life-threatening anemia in heavily parasitized animals. Controlling worms in these animals is complicated by the fact that their parasites develop resistance to dewormers very easily.


Managing parasites in your herd requires an integrated effort focused on prevention, along with routine screening for problems and appropriate treatment strategies. Overcrowding can be a major contributing factor to parasite build up. In our area, an ideal stocking density is two to three sheep or goats per acre (not counting unweaned babies). This can be stretched up to six per acre with quality hay and careful pasture management. The time around lambing/kidding is the highest risk period. Use a combination of the FAMACHA system and fecal egg counts to determine which animals need treatment before the problem escalates.


Remember that young animals are also susceptible to coccidia, a protozoan parasite that does not respond to dewormers. Coccidia builds up easily in shelters and barns. Regular and thorough removal of fecal matter is critical to prevent this problem. This can be a life-threatening problem especially around weaning so take diarrhea in any recently weaned kid or lamb seriously. This is a very common problem in young stock sold immediately after early weaning.


Many over the counter dewormers are not effective in sheep and goats at label doses. When resistance has been identified as an issue, copper oxide wire particle (COWP) boluses can improve the efficacy of dewormers. Work with your veterinarian to ensure that you are using safe and effective doses of dewormer and COWP

© Old Dominion Veterinary Services.

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