About 2 months ago I adopted a 3y/o min pin. He was rescued by police out of an apartment where he was left for dead, & placed in a shelter. There he got kennel cough, but was treated for it before adoption. I have taken him to my vet who assures nothing is wrong, but gave him an antibiotic anyway. The reason for the vet visit was a real foul odor on his breath, which I was told was from a sinus infection. After 14 days on antibiotic, he was fine for 3-4 days then the odor returned. We did another round of antis, the odor stopped for 2-3 days & now he has a very foul metallic odor on his breath. Just in the last 2 days he has started acting funny- not jumping on furniture, yelping for no reason, just not being himself. Is it possible that he could be constipated now from all the antis, or does this sound like an obstruction in his bowels? And is there anything over the counter that is safe to give him for constipation? He is overweight (19 lbs.) & I am working hard to get him down to an acceptable weight (losing about a lb. a week). Please I need some help for this little guy & just cant afford a vet visit everytime he acts a little funny. Am I being too worried for nothing, or should I just goto the vet immediately?? Help please- I just cant stand to see him not feeling well as he has had such a horrible short life already. There has been no vomiting & he is still eating dog bones & I make homemade food (ground turkey,mixed veggies, & brown rice) for his dinner every night, if that helps any. Any advice or previous expereince with these symptoms, I would greatly appreicate any feedback or remedies!!