Flat chests, characterised by a dorsoventral flattening of the rib cage, affect 3 to 4 per cent of all Burmese kittens born in the United Kingdom. Similar deformities have been reported in kittens born to taurine-depleted queens. In an investigation of whether there might be a relationship between whole blood taurine levels and the appearance of flat chests it was found that Burmese kittens had significantly (P<0.05) higher whole blood taurine levels than Burmese queens. In addition, flatchested Burmese kittens had higher mean (sd) levels (789  μmol/litre) than unaffected Burmese kittens (702  μmol/litre) and non-Burmese kittens (597  μmol/litre), although these differences were not statistically significant. Higher levels of taurine were found in the skeletal muscle and lower levels in the heart muscle of the flat-chested Burmese kittens than in normal non-Burmese kittens.