female cairn new aggressive behavior

Question
QUESTION: Our 7yr old female Cairn Terrier has recently been seriously aggressive towards our 10 mos. old female Cairn/Westie puppy. They have gotten along just fine since we brought Taffy home last august. We have not seen any signs of Taffy trying to gain dominance, so these episodes seem unwarranted. Harmony has always been a good natured, much loved, mostly well-behaved dog, so we are very worried and shocked by her behavior. Is there anything we can do to stop this? We have yelled 'NO!' STOP, Harmony!" but have not, nor would attempt to get between them. Would you have any insight on why she would just now start being aggressive? I hate to even ask someone about this, as it makes Harmony sound so mean and she isn't normally. Any suggestions or information would be helpful. We researched breeds before choosing a Cairn, and I feel confident that we understand their nature even though she is the first Cairn we have owned.

ANSWER: Fran -

I apologize for not getting back to you sooner. I was going through the process of having my aunt pass away, and I was the only family member in the area.

Anyway, my very first suggestion is to have Harmony examined by a vet. When sudden or out of character behaviors pop up, it's well worth the money for a trip to the vet in order to rule out anything medical.  Medical changes are the absolute most common reason for new significant behavior changes.

If medical things are ruled out, I am a little unsure what to say.  Perhaps it is because Taffy is reaching adulthood ?  Has she had her first heat or is she spayed ?  If Taffy's coming into heat, that might change the dynamics between them.

You don't mention whether or not Harmony is actually attacking Taffy or just making a big ruckous.  If there has been, or you think there might be, please put a leash on Harmony (or better yet, both of them) and just let her drag is around 24-7.  This will give you the ability to get in close and break up a fight without the chance of being hurt by accident.  Just grab the leash and pull steadily backwards. She will soon attempt to get a "better" grasp on Taffy, which will give you the chance to pull her away.  If they both have leashes on, and there are 2 of you, you each pull steadlily but not harshly in opposite directions until Harmony tries for a new grasp.

Then immediately, and without saying anything to her, crate Harmony for about 20 minutes. Completely ignore her no matter how mad you are. They just hate being ignored.  In fact, if you can catch Harmony giving Taffy "the eye" or showing any significant body language leading up to her nasty behavior, just crate her for 10 minutes right off the bat.  Again, don't say anything to her.

Now, without being actually present to watch the body language between them, I can't tell you any more.  I sure hope this gives you someplace to start.

Again, my apologies.

-Beth

---------- FOLLOW-UP ----------

QUESTION: Beth-
No apologies necessary! We appreciate you even taking time to help us during this time.
Thanks so much for giving us some help with Harmony. We have considered medical problems and  plan to get her to the vet as soon as possible. Taffy was spayed at 6mos and never went into heat. It appears to us that Harmony IS attacking Taffy, yet she has not injured Taffy except for a spot on T's ear and one on her nose, but neither drew blood. However, it all sounds horrible and although T. is not 'fighting back', Harmony does not seem to want to 'give it up'. I am not sure what the conflict would be labeled, but we do feel it is definitely more than just a noisy ruckus.
We implemented the crating today from what we call an 'attack'. Harmony did NOT like it and we completely ignored her and set the timer for 20 minutes.
My question now is: How do we treat her when getting her out of her crate? Do we just open the door and let her out? Or do we give her some attention? Tonight, when she was let out, we were eating dinner and they must stay in their beds while we eat. (she knows that rule); so I simply led her by her leash over to her bed and told her we were eating, get in your bed. Then I went and finished my dinner.

Also, do we allow them to play together while trying to contain Harmony's behavior? They are still 'friends' for most of the day, even after an episode.
Thanks again for getting us started with some correct actions.

Answer
Fran -

You may think I'm mean, but I would just open the door and let her out without any attention.  When she seeks your attention you can give it, but not anything in particular - a little scritch is fine. Sounds like you handled it perfectly.

You should consider picking up all toys or chews until you can be sure they are not the source of this tension.  It's pretty common for things like this to become the excuse to get annoyed with the other dog.

Here are a couple of quick things to read through. I recommend them to anyone with a cairn in their life even if you do not specifically need the information at this particular moment:

http://cairnrescue.com/general/index.htm#toto

http://cairnrescue.com/docs/NILIF.pdf

-Beth