At this hour, I can only make the briefest remarks; back much later, I hope, maybe with more detail.
You're asking a lot of a 12.5-year-old Bichon to accept a new dog in the hous, especially since she's never lived with another dog before. I"d keep that in mind. How is Lila's health; is it good? If so, that will help.
Do you have another person (or more) in the household? Sorry I don't remember if you've said so.
I'd make every effort to have the dogs meet away from inside your house, and to introduce them at a distance from each other to begin with; then to close the distance gradually, as the dogs (both) seem to accept that easily. Might be best away from the house; for instance, take Lila with you when you go to pick up Fonzi. Which then puts you in the position of having both dogs in the car! Best, then, if you have another human in the car as well, unless you have individual crates, one for each dog, in the car.
I'm not doing so well here; sorry. It's possible, or maybe even likely, that Fonzi would be interested in Lila; I'm not sure the reverse would be true.
I'd see to it that Lila has her safe area where you wouldn't encourage Fonzi to use Lila's stuff, but give him his similar stuff at a distance from Lila.
Let's call Lila Senior Resident, and Fonzi, Junior Resident. Things will be easier, I believe, because they are of opposite sex.
In principle, both dogs should get the same needs met about the same time, but Senior Resident gets hers met first, then Junior Resident, right after that. The idea is, similar, but separated from each other to some extent.
You could even confine Fonzi to some area of his own in the house; don't, then, let it be one Lila particularly likes and uses. Things will be easier, I trust, outdoors.
I'd at least make sure the dogs meet outdoors before you take them both into the house.
Have lots and lots of tiny, tiny, high-value (to the dogs) treats handy, and use them judiciously at the crucial times.
I like to feed both dogs at once to begin with; if you have two people, great; if not, you presumably have two hands.
Later, as the dogs gain confidence (especially, Lila, learning Fonzi isn't going to take over her place), you can say, "One for Lila"; (feed); then, "One for Fonzi"; (feed). I like to have the dogs sit for this ritual.
If they're not too distracted (and they may be), you could do that outside first, before bringing the dogs into the house.
Outside, it's good to have a handler for each dog, and walk parallel; you can go back and forth to gain walking distance. When you allow them closer to each other, move in arcs, not directly at the other dog.
See the works of Turid Rugaas; you might still have time to order the book and DVD, say, from Amazon, on calming signals before you go to get Fonzi.
Hope I can be more coherent after more sleep!
Wed, 4 Apr 2012 01:13:36 (PDT)