spruce buds? probably a bit niche unless you live near forestry but while both dogs really like them, Quarrie has to be wrestled away! although he doesn seem to want to eat them, just snort them.
Don't think we've encountered a spruce bud, as far as seasonal obsessions mine are currently in love with the blackbird fledglings from the tree at the end of the driveway and spend many hours staring at it. The nest is just high enough that they can glide out and plop onto the lawn but not quite get back over the fence to safety. Every time I want to let the dogs out I have to go out first and scoop fledglings.
Amy greyhound eats beech mast and hazelnuts when they are in season - and Flick eats blackberry leaves, all year round! She is very particular, only ever blackberry leaves though...
Bear is obsessed with dandelions. If I dig one up, he takes it off to eat. They are both still obsessed with the fish. It's a key word that makes them gallop out to the garden.