Vitamin A poisoning

Excess vitamin A either in the diet or by injection can cause pathological changes in the pig. If oil based injections to excess are given at weaning time high levels may interfere with the growth of the embryo and foetus.

In older stock exposure to more than 25,000iu/kg in the feed causes growth plate changes.

Clinical signs

  • Extreme cases of OCD.
  • Bent legs at the growth plate.
  • Shortened bones.
  • Severe
  • Dipped pasterns in breeding stock.
  • Lameness.
  • Piglets born with growth plate changes.


A history of feeding high levels of vitamin A to both sows and growing pigs and shortened bent legs in piglets and weaned pigs would suggest poisoning.


  • The changes in the bones are irreversible.
  • Reduce the vitamin A levels in the diet.