Hi. This does sound like an internal infection, but it could also be kidney problems and several other possibilities ... make sure your vet does bloods to check for these. Please make sure you get to a vet asap, and preferably today, as the symptoms could indicate something quite serious, but possibly treatable if you get it professionally diagnosed early. Tony
Time for the vet. Begin now to wrap your mind around the possibility of euthanization, as old dogs do not tolerate alot of treatments well. I am sorry that you old friend is so sick. - Blu
It sounds like he has an infection and is probably feeling very crummy. Please call your vet!