chihuahua agression towards yorkie!

Question
hi! i have two 1&1/2 yr. old tea cup chihuahua's that are not spayed, and my husband bought me a 3 month old yorkie for my birthday! the chi's were very accepting at first, only growling once in a while when he got close to them, but accepted him, and run and play, and share toys, and play tugo war with him, and play fight and growl and chase each othe. the yorkie is now 5 monthes old, and suddenly my larger chi, ( 5 lbs) went over to my yorkie while sleeping, and attacked him, leaving him crying, I yelled at her and picked up my yorkie and took him to bed with me. the very next day, the yorkie jumped on the couch where the chi was, and she again atrtacked, this time breaking the skin on his nose. This time I spanked her and yelled at her. Is she a mean dog? should I just find her a home? I have a friend with 5 chi's and wantsher. she says chi get along with chi's only. Is that true? or can this be corrected? Thank you so much for your time... I love all my dogs and don't want to see anyone hurt, but cant decide what to do. Is it ok to leave them alone when I go to work, or should I separate them?.. again.. thank you!

Answer
Dear Leigh,

My first recommendation is to go to http://www.apdt.com and do a search for a good behaviorist CPDT in your area.  I believe this would be the best way to determine exactly what is going on with the dogs.  The behaviorist will be able to meet the dogs and you, size up the various dynamics in play, and help you determine whether this is something you have the time and energy to handle.

This is not to say that it's necessarily a huge problem.  Yes, you are right to seek help once a dog has broken another's skin, and yes it could be a big problem for you in the future.  But it could also be a shortish transition period for everyone which you all look back on in a year and laugh about because they're all getting along famously.  

I can't give you an expert opinion regarding chi's ability to get along with other breeds.  I have seen them do fine with others, but I do hear from some owners that their chi's are tough to deal with at times.  Anytime a new dog is introduced to an established dog or dogs in a household, you can expect some initial issues with the puppy being too rambuctious and upsetting the apple cart so to speak.  For your chi to have gone up to the pup while he was sleeping is definitely odd and I think a bit alarming.  The latter incident on the couch is much more common and predictable, and modifiable as well.  

I wouldn't immediately start looking for a new home for any of the dogs.  I also wouldn't leave them all together alone until you're confident they can get along.  When you need to be away, put the yorkie in a different room for now.  Generally it will help the situation if you can give your chi's attention when the pup is around and ignore them when the pup is absent; this will help to get them to look forward to his presence.  Do your best not to get stressed by the situation when they are all together; your chi's may interpret this to mean that the pup is causing the problem.

I do believe you can modify the behavior of your chihuahua, but you're going to need the assistance and advice of a qualified behaviorist as given at the APDT website above.

Good luck and thanks for writing.
Suzanne Harris, BSc, CPDT
http://www.dogdaysUSA.com