You need to upgrade the security to Rottweiler - like mine - but also I would still invest in a 19mm link chain from Pragmatis or someone else reputable (not cheap ones off ebay - Chain needs to be £150) - combined with a Abloy 62 closed shackle padlock and a ground anchor.
Dogs can be distracted!
Chains can be cut - Oxy or Grinder - but both together are a good deterent.
But if thieves want it they will get it - previous bad experience.
Locked bikes, locked garage, alarm, steel security doors, garage defenders, hasp and staples on doors to frame with Squire CS45 padlocks, 13mm chains on bikes and ground anchors, abus padlocks on chains - middle of day - broke into garage through back door - crowbars, angle grinders and bolt croppers - then cut free all bikes inside - waited for wife to go out as cars wer tight to door - unbolted garage door from inside (took out frame from brickwork) stole 2 bikes - had another 2 lined up to go - but wife came back and they decided to go rather than challenge her (4 guys) dropping the door on my new CBR 600 - ended up loosing Yamaha 90 - New Christmas present - never ridden and XR400 - The quad and CBR 600 were left - but 1 more minute they would have been gone also.
Police took 2 hours to respond!