setblock ~ ~ ~ minecraft:spawner{SpawnData:{id:"minecraft:wolf"}}
will set a spawner with a wolf inside, but it won't actually spawn it.
setblock ~ ~ ~ minecraft:spawner{SpawnData:{id:"minecraft:wolf"}}
will set a spawner with a wolf inside, but it won't actually spawn it.
Are there grass blocks nearby with the appropriate light levels? If yes, please attach a screenshot.