Dogs perform many roles for people, such as hunting, herding, pulling loads, protection, assisting police and military, companionship, and, more recently, aiding handicapped individuals. This impact on human society has given them the nickname  man's best friend  in the Western world.
When looking to acquire nickels with Silver content, look for Silver War Nickels. The term Silver War Nickels refers to those produced by the United States Mint from mid-1942 to 1945. These nickels differ from those minted before and after World War II, as those were made from 56% copper, 35% Silver and 9% manganese.
The years 1965 through 1970 are the halves minted with silver, often overlooked, they are the ones of interest to you. As with most modern era coins, if yours are worn they are valued by their precious metal content and not higher as a collectible.