Differences in IEL subpopulations in the small and large bowel between newborn and adult dogs. Flow cytometrical characterization of leukocyte marker expression in IEL isolated from the small (SB) and large bowel (LB) in 15 healthy adult (AD) and 6 newborn (NB) Beagle dogs showing CD4⁺ TCRαβ⁺ IEL (A), CD8⁺ TCRαβ⁺ IEL (B), CD4⁻CD8⁻ TCRαβ⁺ IEL (C), and CD4⁻CD8⁻ TCRγδ⁺ IEL (D). ** p < 0.005, *** p ≤ 0.0005.