A PhD research project carried out at The Norwegian School of
Veterinary Science has revealed that 50.7% of Norwegian standard
bred horses of the same age suffer from loose bone fragments and
defects in their joints. Genetic analyses show that
osteochondrosis occurring in the hock and Birkeland fractures in
the fetlock are caused by complex, hereditary diseases, which
must be taken into account in breeding. Osteochondrosis,
Birkeland fractures and other loose fragments in joints are
frequently occurring orthopaedic diseases in horses. These
diseases can result in lameness and weaker performance and
therefore have a significant effect on both the horses' welfare
and on profitability in the horse industry. Sigrid Lykkjen,
doctor of veterinary medicine, took x-rays of 464 one-year old
standard bred trotters born in 2006 and 2007 and discovered that
21.5% of them had osteochondrosis in the hock and 23.1% suffered
from Birkeland fractures of the fetlock. The occurrence of
osteochondrosis was significantly higher t