Introduction: Adenoviruses are important in public health. They are used as indicators for microbial pollution source tracking (MST), and as vaccine vectors. Knowledge of host specificity and pre-existing immunity are critical for the two applications. Bovine and porcine adenoviruses are expected to be widespread in the environment through agriculture. Here we examined if bovine and porcine adenovirus strains are truly distinctive from other adenovirus strains. Methods: 46 adenovirus strains with complete genome were downloaded from the RefSeq database of Gen-Bank. 450 bp of nucleotides each at positions 1- 450, 18001-18450, and 27001 – 27450 of the respective strains were subjected to the Disparity Index Test using Mega 7 software. Analysis focused on four adenovirus strains: Bo-vine B, Bovine D, Porcine C and Porcine 3. The total number of strains that were significantly different (P<0.05) from these four strains on a pairwise comparison basis were counted. Results: Bovine D was the most distinctive, reporting significant differences from 34 other adenovirus strains out of the 46 strains. Both Bovine B and Porcine 3 were sig-nificantly different from 22 other strains; while Porcine C was only significantly different from 12 other strains. Con-clusion: Not all bovine adenoviruses are equivalent in terms of nucleotide heterogeneity patterns, the same goes to the porcine adenoviruses. The mechanisms behind such variations among the same hosts should be further explored, in order to avoid the application pitfalls of using these adenoviruses strains for MST, or in designing vaccine vectors.