Some things to think about with Yorkies and Birds..   
Yorkies are rat hunters...aka bird is a rat with wings to them..I know this from experience.   
Yorkies can get to areas in bird cages to eat the food, seeds, nuts, treat, and poop.   
Many birds carry coccidia or other parasites in their excrement.    
I owned a Macaw for 10 years. For 5 of those everything was fine with the dogs and the bird. Not one attempt to harm from either side. One day I was outside talking to the mailman and a neighbor when I heard a ruckus in the house. Low and behold the bird (Rena) was on the floor and being plucked by the dogs (4 of the 5) and they had in that short, 10 mins max, plucked all but her head and wing feathers off of her with blood of course from most of those places where feathers had been. Off to ER vet, 900 bucks later a lesson was learned. Never even for a split second allow them together alone, even taking a shower....   
Also, being a breeder, I have always taken my pups to be checked at the vet prior to going to their new homes. One such time, a stool check showed coccidia. Treated the pups and rechecked. Still with coccidia.....after 3 treatments I thought about the fact that the little rascals were always getting under Renas cage and eating whatever she dropped. So I put a gate around the area and the coccidia was gone. So I asked my vet and he confirmed that yes indeed that could have been the cause.  So I treated the bird and the pups and kept them out of that area and have not had that issue since.   
I found that with exhibiting now and the time for grooming, care, etc with the dogs I was neglecting Rena. I placed her an aviary home setting and she is doing wonderful. I have visited her twice and she is quite happy there. It broke my heart to do it, but when a bird is in the cage more than the bird is out, in my opinion, it is neglectful. I miss her everyday. She called me mom, gave me kisses, protected me from everyone, and I still cry about placing her. However, it was for her that I did it.     
				__________________  "The minute you settle for less than you deserve, you get even less than you settled for."     |