Blood clinical-chemical parameters (BCCPs) are used to investigate physiological consequences attributed to exposure to anthropogenic stressors, such as exposure to Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) and Dechlorane Plus (DP), which are flame retardants (FRs), on avian health. Japanese quail (Coturnix japonica) were used as a model species to investigate individual and mixture effects of both FRs by injecting different concentrations (5, 50, or 500 ng/µL) of either of these compounds as well as a 1:1 mixture of both into fertilized eggs. To estimate post-hatching effects, 18 BCCPs were evaluated from 101 chicks at day 14. Albumin levels were found to be significantly elevated in the groups exposed to high doses of TDCIPP alone as well as a mixture of TDCIPP and DP. However, during the course of the study, the initial corn-based feed had to be substituted by a fishmeal-based feed. The 8 days consuming the new feed played a significant role on 12 of 18 BCCPs measured. Consequently, it is recommended that dietary habits need to be considered when investigating the physiological impact of contaminants using BCCPs as biomarkers in growing nestlings both in controlled in vivo and field experiments.