Jan 29, Hi, I'm interested in using waste coffee grounds in my garden but I have a dog. I have a whole bunch of questions about the process-- mostly. It's good that our dogs and cats don't depend on caffeine to get through the day. Most people name coffee as the number one source of caffeine. And they are. We used to have sign in our lobby that said “Any unsupervised children will get a cup of espresso and a free puppy.” We took it down after one of the clients.