Figure. Maximum-likelihood tree comparing 108 strains of severe acute respiratory syndrome coronavirus 2 circulating among humans and canines. Tree shows 107 complete genomes downloaded from the GISAID database (https://www.gisaid.org) and the strains sequenced from an infected dog and family member in Italy (bold red text). The tree was built with IQ-TREE version 1.6.10 (http://www.iqtree.org) using the best fit model indicated by the Model Finder with 1,000 bootstrap replicates. Text at nodes indicates bootstrap values >70. Brackets to the right indicate clades. Scale bar indicates number of nucleotide substitutions per site.