Oh poor Coco, I hope you feel better soon. Sinusitis is never fun and it is so hard to see our babies not feeling well. When you say he has been to the vet twice in the last two months, is this the same case of sinusitis that wont go away or has he contracted sinusitis more than once? If he has had the same case for two months, that seems extraordinary long. I have never heard of a chronic sinusitis. Sinusitis by definition is the inflammation of the sinus cavities - which can be bacterial, viral, fungal, etc. If it is bacterial or fungal then there should be medications to kill the infection. I know if it is viral, then it is up to his immune system to kick the cold. Is there not any anti-inflammatory meds to help decrease some of the inflam he is expereincing? You would think this would make him feel better.. Well, Medusa, I am thinking of sweet Coco and I hope his sinuses clear up and he can get back to being that active baby you love.