Hello, I'm Dr. Deb and I'll do my best to help you today.
I'm so sorry that Woody has bladder cancer. As your vet probably told you, most of these cancers are not operable, unfortunately.
We often recommend that they be started on Piroxicam, an anti-inflammatory drug which is thought to slow down the cancer process. I say "thought" to slow down the process because there have been no controlled studies which actually prove that this happens for every type of cancer. But it would appear to help many of them and it's what I always recommend.
I also recommend fish oil supplements since they have anti-inflammatory properties as well. Welactin and 3V-Capsules are veterinary versions which are specifically formulated for dogs and are good quality products.
There is also a prescription diet called N/D which would have to be obtained from your vet. It comes in cans only because it contains so much fish oil that it couldn't be made into a kibble. The idea is that low carbohydrates, medium to high protein and high fatty acid diets may be helpful for cancer patients.
If you search the internet, you will find cancer diets but many of them are not nutritionally balanced so I would be somewhat wary of them.
Probiotics such as Forti Flora may be helpful; these products can help boost the immune system. Many pet stores carry them or they are availalbe on the internet.
There are a number of spices shown to have anti-cancer activity.
Garlic --Try FRESH minced garlic - about 1 clove per 40 pounds of body weight. Be careful of the dose, though, since in large amounts, garlic can cause toxicity (anemia). A cbc (complete blood count) should be monitored regularly to monitor potential problems.