Not all dogs: bloodhounds.
In Relationshits I wrote about one important friendship, that between generals Grant and Sherman and how that friendship saved the Union, saved the principle of government of the people by the people. I mentioned the battles of Shiloh and Corinth in Mississippi—the Deep South. There was also the long campaign to besiege Vicksburg where the Union Army travelled hundreds of miles in Mississippi and fought and won five battles. By the time Vicksburg fell slavery no longer existed in Mississippi!
Not all Union people were Abolitionists! Many became such by what they found on the plantations there! In the Deep South slaves were worked harder and longer and were whipped more than elsewhere—Kentucky, Tennessee, Virginia etc.
The Union forces fighting in Mississippi and, after Chattanooga, in Georgia (Battle of Atlanta and then Sherman’s March to the Sea) bloodhounds were shot on sight and whipping posts were destroyed.
The bloodhounds were used to track down escaped slaves and convicts. This enraged the Union troops after what they had seen in their campaigning!
Man’s best friend—not always!
https://books.google.com.au/books?id=kROKDwAAQBAJ&pg=PA206&lpg=PA206&dq=Grant+Mi... Starting about 6:25