Schnauzer seems blah

Question
I have a 6 year old female min. schnauzer that has always been in perfect health.  In the last couple of weeks we've noticed her eyes and behaviour seems more lathargic and like she just doesn't feel well.  It's hard to describe but her eyes don't have the normal "spark" that has always been there.  She eats and drinks the same.  Her bathroom habits haven't changed.  The only thing we've noticed is she has sort of a cough every now and then and she licks her tongue alot like she's trying not to vomit.  I wonder if she may have allergies?  I'm a little nervous mainly because my last min. schnauzer died from kidney failure which was very quite and slipped up on us with very little symptoms and that's made me gun shy.

Answer
You need to take her to the vet for examination and blood tests.  The cough could indicate heart disease.  However, the licking could be a sign of nausea from kidney or liver problems.  Getting on top of the problem now will allow your vet to treat her before anything progresses.