But, I only have a K9FITbone™

That's okay! We can make it work! 
Fitness can happen anywhere, but if I only had one piece of equipment to use, I would pick a K9FITbone™. I can work the rear, the front, the core. I can also get multiple planes - sagittal and frontal and possibly a little bit of transverse. I can also make sure I hit isometric, concentric and eccentric exercises. I can also make exercises more difficult by adding air to the K9FITbone™. As you add more and more air, it rocks more, engaging more of the stabilizer muscles and the core. 
It's always nice to have more than one piece of equipment, but don't give up on conditioning just because you only have one thing. 
This is a video of LaBlanca, a cocker spaniel that competes in agility. She was having some shoulder and back pain and has been in a conditioning program for the past 16 weeks. I love her enthusiasm and focus on maintaining good form. She demonstrates a total of 8 exercises done with the K9FITbone™.