Mutagens and Carcinogens Called Aflatoxins and Their Hydroxylated Metabolites in Food for Domestic Cats

Abstract

Aflatoxins (AFs) in cat food are a serious threat to cat health. The exposure of cats to AFs can cause damage depending on the exposure time and dosage, as well as the diet, nutritional state, age and sex of the cat. The first acute effect of AFs is liver damage, including cellular necrosis, hemorrhage, fibrosis, cirrhosis, immunosuppression, respiratory infection, anorexia, and fever. Chronic exposure to AFs can lead to hepatitis, cirrhosis and cancer in the liver, kidneys, lungs, colon and nervous system. Domestic cats can tolerate up to 0.55 mg of AFB1 per kg of body weight, which is the Lethal Dose 50% (LD50) that causes acute toxicity. Subacute aflatoxicosis (0.5-1 mg of AF/kg of food for cats) produces anorexia, drowsiness, jaundice, intravascular coagulation, hematomas, hemorrhagic gut and death in 2 to 3 weeks. For cats, hepatotoxic effects occur with chronic exposure to AFs at 0.05-0.3 mg of AF/kg of food over 6 to 8 weeks. Cat food samples, including 21 croquette samples and 32 semi-liquid food samples in envelopes and cans, were purchased from Mexico City markets from October 22, 2014 to January 10, 2015. A method for the analysis of AFs that included immunoaffinity columns, derivatization and quantification by HPLC was validated and used. For the croquettes, the best sample brands had no basic AFs; however, when hydroxylated AF metabolites were considered, the average AF contamination increased from 4.98 to 20.87 µg kg-1 , values that are still within the AF tolerance level of 20 µg kg-1 . For the semi-liquid cat food samples in cans and envelopes, 23 of the 53 samples, or 43%, had no basic AFs; however, they were all contaminated when AF hydroxylates were assessed, with concentrations ranging from 2.76 to 15,974 µg kg-1 . The protective ingredients used in cat food differ from those used in dog food, as no hydrated sodium calcium aluminosilicates, glucomannans, are used, and only one sample had flaxseed omega -3 and -6 fatty acids.