Canine TCC... Treatment Advice Needed

Our lab Riley will be 12 in November.  He was recently diagnosed with TCC Bladder cancer.  We started on Piroxicam and he is taking 12mg. every other day (after two weeks of every day).

 He's also taking something to help prevent stomach ulcers that apparently Piroxicam can cause but this one (Misoprostol) makes him puke.  And he's started having pain when pooping I think.

 I'm about ready to stop all the meds and just see how he does.  Has anyone had similar issues?  Will stopping Misoprostol so he doesn't puke all the time help?  I'm giving all the meds with food, he hasn't lost weight yet and is very active, fit (even for a lab) and happy boy otherwise.

Any ideas or thoughts would be greatly appreciated. 

Do not stop the piroxicam...Perhaps you can talk to your vet about prednisone or even celebrex. Anything goes for Abby's diet. Some days it's kibble and chicken, then hamburger, then whatever I can find. She loves variety. These meds can hinder a dogs appetite, so you need to be creative. Beefy gravy, smelly fish oils and hard boiled eggs are options.

Make sure Riley is getting lots of water. This has been a huge challenge with Abby. I have a bowl of fresh water on each floor of my place and I mak sure she drinks. It's not easy, but I do it. So can you. I understand. I hope Riley will be O.K.