After a week in the hospital my lab Dexter is now salivating copious amounts of brown saliva! Now what is this? He's had ultrasounds, xrays, bloodwork bone marrow tests..... He has no appetite, his mouth has been checked but nothing is noticeable. They are going to sedate him to examine him more fully. He does not act sick, I took him out and he still knocks me over. He has been on antibiotics. Any ideas?