The presence of cereals and grains in the formulation of pet foods suggests the need to control aflatoxin contamination in these foods. The objective of the study was to analyse domestic pet food to determine the occurrence of aflatoxins as well as their risk to animal health. One hundred food samples (45 for dogs, 25 for cats, 30 for birds) were collected at random from pet shops in Alfenas city, south-east Brazil. Thin-layer chromatography was used for separation, identification and quantification of the compounds after validation of the method. Aflatoxins were detected in 12.0% of the samples. Levels of aflatoxins (B(1) + B(2) + G(1) + G(2)) above the maximum limit established in Brazil (50 microg kg(-1)) for animal food were detected in five of the 12 positive samples (41.7%). The concentration of total aflatoxins was 15-374 microg kg(-1) (mean 131 microg kg(-1)). All samples containing peanuts were positive for aflatoxin B(1). Aflatoxins are carcinogenic and their consumption might be a risk for domestic animal health. The high prevalence of aflatoxin B(1) in foods prepared for birds, species highly susceptible to aflatoxins, shows the need for the re-evaluation of the use of peanuts (present in seven of the eight samples positives for aflatoxin) and/or the addition of fungicides to the food.