Adverse food reactions in dogs due to antibiotic residues in pet food: A preliminary study

In the last decades adverse food reactions considerably increased in dogs and cats. We reported the onset of food intolerances symptoms, including otitis, diarrhoea, generalized anxiety, and dermatitis, in a cohort of 8 dogs consuming commercial diets. All dogs were supplemented with an organic chicken-based diet for 15 days. Blood biochemical parameters, kibbles composition, oxytetracycline (OTC) serum concentration were performed before and after 15 days of organic chicken-based diet supplementation. We hypothesize that a chronic intake of contaminated food, enhanced also by the presence of nanoparticle aggregates, might be at the base of pharmacologic or idiopathic food intolerances onset. Biochemical analyses indicated a significant increase in the alkaline phosphatase, from 41 to 52.5 U/L, after 15 days (**p < 0.01), while a significant decrease in Gamma-glutamyl transferase and urea, from 9.37 to 6.25 U/L and from 32.13 ± 8.72 to 22.13 ± 7.8 mg/dL, respectively, was observed (*p < 0.05). A significant decrease in mean OTC serum concentration was also observed from 0.22 to 0.02 μg/mL (**p < 0.01). Kibbles composition analysis revealed the presence of OTC, calcium, aluminium, silicon, and phosphorous nanoparticle aggregates. These preliminary observations deserve further detailed studies on a wider sample size to confirm our hypothesis.