The phrase “dog in the manger” refers to a person who prevents others from using or enjoying something, even though they themselves do not want or need it. It originates from one of Aesop’s fables, where a dog lies in a manger filled with hay. Although the dog cannot eat the hay, it prevents the oxen from eating it, showing selfishness and spite.
A “dog in the manger attitude” describes someone who behaves similarly by blocking others from benefiting from something, even though they gain no advantage from doing so.