Hi, my estranged father was recently sent to prison and rather than sending them to a shelter, I took in his dog and cat. The dog is an 11-12 year old longhaired miniature dachshund, and I just noticed his belly was COVERED in little black spots. I removed a couple of them and put them in water and sure enough, it turned reddish brown. I haven't seen any actual fleas on him, but the flea dirt is absolutely everywhere on him. There were also larger dark spots on his belly (I'll try to insert a pic) that at first I thought might be some sort of skin cancer, but when I gave him a bath in hopes of getting some of the flea dirt off, the larger spots just came off??!! I know my father loved this dog but I don't see how he let him get this bad, ugh. How should I go about treating him? Should I also treat his cat and my own dog and cats? Thanks.