There are definately alot of weird sounds in the song - the shaker especially is one that usually will get a dog/cats attention, it also kinda sounds like a "swarm of bees" in the background at a couple of spots there too. The sounds also shift from right speaker to left speaker & back again that will also generate a response, so will Robert Page's moaning - moans are always interesting to dogs.
According to
http://en.wikipedia.org/wiki/Whole_Lotta_Love there is also "sonic wave sound" and the "backwards echo technique" used during the song.
I would say given that it's Led Zeppelin
and that it first came out in 1969-70
well you draw your own conclusion but I doubt it was directed towards canines