Histamine in cat foods: survey and comparison of methodologies

Histamine concentrations were determined in semi-moist and moist cat foods which listed fish or fish solubles as one of the ingredients using the AOAC fluorometic method and a TLC procedure. Percent recovery was 73% for the AOAC and 96% for the TLC procedure, although the coefficient of variation was lower for AOAC procedure. Moist cat foods contained an average of 11 ppm histamine while semi-moist cat foods had 23 ppm histamine. High histamine content of semi-moist cat food was probably due to condensed fish solubles even though it was not one of the major ingredients. The maximum amount of histamine observed was 88.8 ppm in a semi-moist cat food sample while the minimum was 3.8 ppm in a moist cat food sample. Results from both procedure compared well.