I had three yorkies cost me over $7,000 between Nov. 2011 and May 2012 ...
One was for a salivary gland that had to be removed - it suddenly started leaking and his throat was so swollen.
One had extensive testing for lymphangectasia, a protein losing enteropathy.
One had surgery for hip dysplasia.
All but one of my yorkies needed dentals this year. That is $170 plus the cost of labs that are done prior to the dental. I take all of mine to the vet at least yearly for blood work which includes heartworm testing.
There are SO many things that seem to crop up in this breed. My vet's partner was teasing me one day about how I picked the wrong breed.
Many of them are prone to pancreatitis and other GI issues. One bout of pancreatitis can be anywhere from a few hundred up. All depends upon the severity of it.
And, yes, they often have problems with their knees....one jump off of a chair or sofa and they can tear a ligament...actually they can tear one running in the yard. One sudden turn and bang it is torn. Without surgery, they end up with severe, very painful arthritis.
I am sure there are other things I am not thinking of right now. I think just reading the Sick and Injured forum and also Health and Diet will give you lots of information about yorkie illnesses.
I am not talking about small, under 5 pound yorkies. The ones that I mentioned above are all 6, 7 and 10 pounds.
Oh...and don't forget heartworm preventatives...and yes, grooming! Unless you are skilled...I am not.