Collie eye anomaly in the Lancashire heeler.

An ocular disease ophthalmoscopically identical to collie eye anomaly (CEA) is described in the Lancashire heeler breed of terrier. Survey work completed in 1996 demonstrated a significant incidence of 13.7 per cent. The clinical findings together with initial pedigree analysis support the accepted view that, in the traditionally affected breeds, CEA is a true pleiomorph which segregates as a recessive Mendelian trait. Alternative hypothesis speculates that the several lesions ascribed to CEA may occur as separate congenital disease entities, each with its own mode of inheritance. However, the combination of bilateral chloroidal hypoplasia, papillary or peripapillary coloboma and neuroretinal non-attachment in a non-collie breed tends to confirm that these three lesions are indeed individual parts of the one disease. The established appearance of CEA outwith the collie breeds dictates that the nomenclature for this disease is now somewhat inappropriate and that an alternative name should be considered. It is suggested that the term 'congenital posterior segment anomaly' could be adopted.