Evidence of heredity of cribbing,weaving and stall-walking in thoroughbred horses

The investigation involved 1035 Thoroughbred horses aged 3–8 years and raised in Italy. Eighty trainers were interviewed on the occurrence of anomalous behaviour. The incidence of cribbing, weaving and stall-walking in the horses was 2.4, 2.5 and 2.5%, respectively. The incidence of behavioural defects in families containing identified anomalous horses (“probands”) was much higher than in the surveyed population: 30% for cribbing, 26% for weaving and 13% for stall-walking. This would suggest the involvement of a genetic component in the three vices, but due to the limited data available it was not possible to ascertain the inheritance patterns. Imitation of mares by foals was excluded as a main cause of the vices.