I knew about the carrots and the tomatoes and all that but good reminder!
<possibility of grapes and raisins toxic to dogs though; evidence/direct correlation not conclusive but many vets will say so>
veggies like cucumbers, lettuce mostly water; cucumber is naturally a cooling food due to high water content and vit. c. Dark leafy greens/mixed greens have more nutrition properties than iceberg lettuce.
Cranberry works because the compounds in the cranberry prevent the bacteria from sticking to the bladder walls. If you can manage it, taking cranberry pills is more effective than using the juice because of the sugar in the juice and the sheer amount of juice you'd have to drink to equal the pills. I take cranberry pills daily as I have a history of frequent <like more than 3 x yr.> UTI's. My female Rottie takes the supplement also-