I like what Corzhens had to say and I may want to try her suggestion myself. What I like to use for detoxing my pets is colloidal silver, which can just be dripped into their water dish with a glass eye dropper... as long as the dish itself is not made of plastic or metal, that is. Glass works best for keeping the silver particles intact, so I use glass bowls for my pets and they can't tell the difference in the taste because colloidal silver just tastes like water anyway.
Also, there are pet detox products that we can purchase but quite often I've found that they are more geared for certain conditions rather than treating the whole animal. For example, you may find a product that is meant for urinary tract health, or digestive health, things like that. I think it's more uncommon to find an overall health product for cats or dogs. The stuff can be very expensive too, outrageously so, in fact. Of course, there is also the line of thought that if it aint broke... don't fix it. But I do tend to think of preventive therapies for my pets because vet bills are horribly high even for the simplest problems. No matter how much it costs to buy detox products, the vet bills cost more.