My cat was about 3 years old when I brought our border collie pup aged 10 weeks home. I think at the beginning the cat had the upper hand and everything was fine, but now the dog seems to be a bit jealous and occasionally she gives the cat a little nip. She gets scolded for it, of course. The cat tries to overcome the problem by keeping out of reach.
There are a few labradors living around here and they don't seem to be easy dogs to have. One barks lots and escapes frequently. One escapes frequently but is very friendly and can be caught by various neighbours and brought home. One is a big lump, stands on your feet and is very fussy. Another one, on the other hand, is old, deaf and is a gem.