THE PREVALENCE AND RISK-FACTORS FOR CONGENITAL ENTROPION IN INTENSIVELY REARED LAMBS IN SOUTH-WEST ENGLAND

The presence of entropion in lambs born in early lambing flocks was recorded in three flocks (A, B and C) in south west England over a 3 year period. (1990-1993). In the first year all three flocks were examined and congenital entropion was observed in each flock, 2.7-6.6% of a random sample of approximately 80 lambs per flock were affected. In the second year (1991) when Flocks A and B were observed there were 1.0-1.8% of all flock lambs with entropion. This was associated with breed of sire in Flock A but not Flock B. Flock B was monitored for a third year (1993) and there was a significant association between the presence of entropion and breed of sire. There was a greater proportion of lambs with entropion which had Charollais or Texel sires than those sired by Suffolk rams. Logistic regression analysis of data from 1991 and 1993 indicated that the only significant variable associated with the presence of entropion was breed of sire with Charollais and Texel sired lambs having an increased risk of entropion when compared with Suffolk sired lambs.