Extruded canine diets containing primarily peas in contrast to those containing lamb and chicken meal are at higher risk of mold and mycotoxin contamination when treated similarly: An observational study.

Three extruded dog diets were created for a nutritional study with different primary protein sources (BAS: lamb meal (LM) and deboned lamb (DL); CHK: chicken meal, LM, and DL; PEA: dried ground pea, LM, and DL). All diets were processed using the same single-screw extruder, shipped from the processing facility on the same day, and transported under the same conditions in January 2021. After 8 months of storage in a temperature and humidity-controlled room in September 2021, only the PEA diet was molded upon inspection. Mold and mycotoxin analysis of all diets was conducted in both September 2021 and at expiry in January 2022, which confirmed mold and mycotoxin contamination to some degree in all diets and most pronounced in the PEA diet across both timepoints. Nutrient analysis of all diets was conducted at production and 2 months post-expiry in March 2022. As expected, fatty acid and vitamin contents of all diets decreased between sampling timepoints, and amino acid contents generally remained stable. Methionine decreased by 14% in CHK, cystine decreased by 15% and 20% in CHK and PEA, respectively, tyrosine decreased by 30%, 25%, and 27% across BAS, CHK, and PEA, respectively, and taurine decreased by 50%, 42%, and 55% across BAS, CHK, and PEA, respectively. Inaccurate measurement of the PEA diet moisture content post-production likely led to mold development which may also negatively impact the availability of nutrients and could put dogs at risk for mycotoxicosis and nutrient deficiencies if not closely monitored, but controlled studies are required.