Product Survey of Cat Food for Mycotoxins

The Food Standards Agency commissioned Fera Science Ltd. to carry out a survey to obtain occurrence data for a range of mycotoxins in 20 dry and 20 wet cat food samples at two sampling time points. The mycotoxins requested were aflatoxins, ochratoxin A (OTA), zearalenone (ZEN), deoxynivalenol (DON), T-2, HT-2, diacetoxyscirpenol (DAS), and neosolaniol (NEO). Two accredited methods were used to analyse for these mycotoxins and some additional Fusarium mycotoxins. ISO 17025 Flexible Scope accreditation was used to allow results to be reported as accredited to ISO17025. A third, non-accredited multi-mycotoxin LCMS/MS screening method was also used to analyse the samples for a range of other mycotoxins. For sampling period 1, low levels of aflatoxins B1 and G1 were detected in a small number of dry cat food samples. Ochratoxin A was also detected in a small number of dry cat food samples. The results for period 2 were similar, although more samples contained residues and the maximum level of ochratoxin A found (3.9 µg/kg) was higher than sampling period 1. None of the samples exceeded the maximum level for aflatoxin B1 in complete animal feed or the guidance value for ochratoxin A in cat food. None of the wet cat food samples contained measurable levels of ochratoxin A or aflatoxins. Zearalenone was the most prevalent mycotoxin in dry cat food samples in sampling period 1, it was found in 18 of the 20 samples tested at concentrations in the range 2.5 to 67.4 µg/kg. Deoxynivalenol was detected in 13 of 20 dry cat food samples at concentrations from 11.5 to 575 µg/kg. The highest level of T-2 and HT-2 in a dry cat food was 22.1 µg/kg. Low levels of ZEN and DON were detected in a small number of wet cat food samples. For the Fusarium toxins of specific interest diacetoxyscirpenol (DAS) and neosolaniol (NEO) were not detected in any sample. In addition, Fusarenon X, NIV, T-2 toxin-α-glucoside, α-zearalenol, and β-zearalenol were not detected in any sample. No sample from sampling period 1 exceeded the guidance values for cat food set out in Retained Commission Recommendation (EU) 2016/1319 amending Retained EU Recommendation 2006/576/EC [3, 6]. For sampling period 2, ZEN was detected in all 20 dry cat food samples tested in the range 3.2 to 286 µg/kg. Deoxynivalenol was detected in 13 out of 20 samples at concentrations from 12.4 to 379 µg/kg. There is no specific guidance value for deoxynivalenol in cat food, although there is a guidance value for compound feed for all animals of 5000 µg/kg [6]. There are guidance values for the sum of T-2 and HT-2 toxins, ZEN and ochratoxin A (OTA) [3]. No sample exceeded the guidance values for T-2 and HT-2 toxins. For this method measurement uncertainty for ZEN is ±20.8%. The highest ZEN result was 286 ± 59.5 µg/kg. This result exceeds the guidance value from Retained Commission Recommendation (EU) 2016/1319 for ZEN for ‘adult dogs and cats other than for reproduction’ of 200 µg/kg (3). DAS, Fusarenon X, NEO, NIV, T-2 toxin-α-glucoside, αzearalenol, α-zearalenol-14-glucoside, β-zearalenol-14-glucoside, and ZEN-14-glucoside were not detected above their respective reporting limits in any sample of dry cat food in this period. Very few residues of Fusarium mycotoxins were detected in the wet cat food in the second sampling period, and no sample exceeded the guidance values. The results of the screening analyses showed a similar pattern to the other results, dry foods contained more residues than wet foods, although no sample exceeded any guidance values, where these exist, apart from the ZEN in one sample of dry food which exceeded the guidance value of 200 µg/kg. Mycotoxins from Fusarium species, including trichothecenes, beauvericin, enniatins, fumonisins and fusaric acid were detected in several samples of dry food. Enniatins and beauvericin were most frequently found. Two mycotoxins produced by Penicillium species (mycophenolic acid and roquefortine C) were detected at low levels in samples from period 1 but no Penicillium toxins were detected in the second sampling period. Four dry cat food samples contained multiple ergot alkaloids in sampling period 1 and two samples contained ergot alkaloids in sampling period 2. Tenuazonic acid was tentatively detected in several dry cat foods in period 1, although its identity was only confirmed in five samples. It was detected and its identity confirmed in two samples in period 2. The wet cat food samples contained very few residues of mycotoxins. Two samples in period 1 and one sample in period 2 contained low levels of enniatins (beauvericin was not detected). No other Fusarium or Penicillium mycotoxins were detected. Tenuazonic acid was tentatively detected at low levels in three samples, however its presence was only confirmed in one sample and one sample contained ergot alkaloids in period 1. In conclusion, mycotoxins were frequently detected in dry cat food samples, mycotoxins from several different fungi genera were detected, sometimes co-occurring in the same sample. In sampling period 1, nineteen dry samples contained multiple mycotoxins, ten samples contained ten or more mycotoxins, with as many as nineteen mycotoxins found in one sample. In sampling period 2, there was a similar pattern for dry samples. Twenty samples contained multiple mycotoxins, eight samples contained ten or more mycotoxins of which two contained seventeen mycotoxins each. Overall, the wet samples contained very few or no mycotoxins but one sample in sampling period 1 contained 6 ergot alkaloid compounds. One sample of dry food contained ZEN above the guidance value. No other samples contained mycotoxins above the legislative values in UK retained EU legislation or guidance values where these exist.