cows; weaning; cattle; calves

Cattle production: Deworming your cattle

Question: Is it necessary to deworm cattle? Some people say that only sheep need to be dewormed.

There is a big difference between cattle and sheep regarding worm control. Sheep do get more affected by internal parasites than cattle and in many cases sheep will die due to worms if they are not treated at the right time.

Adult cattle in good condition have good resistance against some internal parasites like wireworm and tapeworm. But this resistance develops over time and can be broken down again if the animals are in bad condition.


  • The cattle that need to be dewormed are the young calves.
  • Effectively, they start eating when they are 2 months of age.
  • This is when they get infected with the immature stage of roundworms and tapeworms on the grass they eat.
  • At this age the calves don’t have any resistance to the worms.
  • This means that all the young worms will attach to the calf’s intestines and grow rapidly.
  • In most cases the calf will not die, but the worms will affect the calf’s growth and health severely.
  • Tapeworms are specifically a problem for small-scale farmers because most of them will keep the animals in a kraal overnight.
  • These kraals are the ideal place for tapeworms to reproduce and survive.
  • A high tapeworm infestation in young calves will lead to potbelly calves that will grow very slowly.
  • Calves born in the summer will also be exposed to the highest roundworm infection level on the grazing.
  • The autumn is the time when most immature worms occur on the grazing, especially if good rain and overcast weather occur for a few days in a row.
  • So, all calves born in the summer must be dewormed now and again 1 to 2 months later with a broad spectrum product which controls all roundworms and tapeworms.
  • If the farmer gets better growth from the calf by controlling roundworms and tapeworms, the calf will gain at least an extra 5 kg to 10 kg before weaning at 7 months of age.
  • Deworming young calves is essential and cost effective.
  • Other cattle that can be dewormed in the autumn are heifers that will be mated for the first time and cows that have calved for the first time.
  • These young cows are still growing and their resistance to worms is not yet fully developed.
  • All other adult cattle in bad condition can also be dewormed for roundworm during autumn.


  • This article was written by Dr. Danie Odendaal and first appeared in Farming SA.

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