My 11 yr old dog has developed a cough. It sounds like he is coughing up a fur ball at the end but until about 3 months ago he didn't do it. He is overweight which is something we have struggled with

It could be Congested Heart Failure. You need to take him in. Older dogs need their bumps and bruises looked at closely by a vet... Coughing that all of a sudden pops up with no other symptoms is not a good sign.

Even if your dog has gotten the doggy cold, being an older dog.. this disease could take his life

Off to the vet you go!