Survey and risk assessment of the mycotoxins deoxynivalenol, zearalenone, fumonisins, ochratoxin A, and aflatoxins in commercial dry dog food

Abstract

The aim of the present study was to investigate the occurrence of mycotoxins in commercial dog food, as a basis to estimate the risk of adverse effects. Seventy-six dry dog food samples from 27 producers were purchased from retail shops, supermarkets, and specialized pet food shops in Vienna, Austria. The frequency and levels of deoxynivalenol (DON), zearalenone (ZEA), fumonisins (FUM), ochratoxin A (OTA). and aflatoxins (AF) in dry dog food were determined. Mycotoxin analysis were performed by commercial enzyme-linked immunosorbent assay (ELISA) test kits. Confirmatory analyses were done for DON, ZEA, and FUM by high performance liquid chromatography (HPLC) after extract clean-up with immunoaffinity columns. The correlations between ELISA and HPLC results for DON and ZEA were acceptable and indicated that ELISA could be a simple, low cost, and sensitive screening tool for mycotoxins detection, contributing to quality and safety of pet food. DON was the mycotoxin most frequently found (83% positives; median 308 µg/kg, maximum 1,390 µg/kg). ZEA (47% positives, median 51 µg/kg and maximum 298 µg/kg) and FUM (42% positives, median 122 µg/kg and maximum 568 µg/kg) were also frequently detected in dog food. OTA was less frequently found (5%, median 3.6 µg/kg, maximum 4.7 µg/kg. AF were not detected (<0.5 µg/kg) in any sample. The results show that dry dog food marketed in Vienna are frequently contaminated with mycotoxins (DON > ZEA > FUM > OTA) in low concentrations, but do not contain AF. The high frequency of Fusarium toxins DON, ZEA, and FUM indicates the need for intensive control measures to prevent mycotoxins in dog foods. The mycotoxin levels found in dry dog food are considered as safe in aspects of acute mycotoxicoses. However, repeated and long-time exposure of dogs to low levels of mycotoxins may pose a health risk.

Occurrence of mycotoxins in extruded commercial dog food

“…Unlike the present study, the survey conducted in Austria by Böhm et al (2010) revealed a widespread and substantial ZEA contamination; in fact, 47% of the dog food samples tested were positive, with a mean and maximum concentration of 51 and 298 g/kg, respectively. A similar heterogeneity of contamination among positive samples and a rather high level of contamination had also emerged during a previous study conducted in Poland by Zwierzchowski et al (2004); the presence of ZEA was observed in no less than 84% of the tested dry dog foods, which belonged to different price ranges.…”

“…In contrast, other studies recently conducted in several European countries showed only a modest presence of aflatoxinsin dog foods, often in non-quantifiable traces or, in any case, in very small concentrations (Martins et al, 2003;López Grío et al, 2010;Böhm et al, 2010). This situation, confirmed by the results of the present study, is likely to be attributable to the effectiveness of the control system currently in force in Europe, particularly with respect to aflatoxins in feed intended for animals.…”

“…Martins et al (2003) found FB 1 to be present in only 5% of the tested samples of pet foods sold in the Portuguese market, with contamination ranging between 12 and 24 g/kg. In the previously cited study conducted in Austria by Böhm et al (2010), the level of fumonisins contamination was likewise rather modest, despite being found in a more significant percentage (42%) of the pet food samples analyzed, with mean and maximum total fumonisins concentrations of 122 and 568 g/kg, respectively. As already pointed out, these values are decidedly lower than the ones revealed in the present study and this is particularly true in the case of standard products, in which mean and maximum levels of contamination of 491 and 1503 g/kg DM, respectively, were observed in the case of FB 1 .…”

“…In the course of an investigation conducted on complete foods intended for the canine species, Songsermsakul et al (2007) found DON contamination in all dry food samples, with a rather broad range of between 22 and 1837 g/kg, and in 27% of wet foods, though in this case the concentrations were lower on average and fell within a narrower range (95-170 g/kg). The widespread presence of DON in dog food has been highlighted more recently also by Böhm et al (2010) in a study, similarly carried out in Austria, in which contamination by this mycotoxin was found in 83% of the dry pet food samples tested, with a mean and maximum concentration of 308 and 1390 g/kg, respectively. Again, these values far exceed those observed in the present study.…”

“…More specifically, the principal mycotoxins investigated were aflatoxins, fumonisins, deoxynivalenol (DON), zearalenone (ZEA) and ochratoxin A (OTA) (Leung et al, 2006;Boermans and Leung, 2007;Songsermsakul et al, 2007;Böhm et al, 2010;Pagliuca et al, 2011).…”