Lula, a disgruntled border collie, writes:

Dear Mickey and Flea,
My name is Lula and I am an absolutely adorable border collie mix. No really, I am gorgeous--everyone says so. For the past 2 years things have been great. My mom rescued me from a shelter and right away, without even trying, I had her wrapped around my finger. I mean, every time she sees me, it's hugs and cuddles. I get fed twice a day (and not the cheap stuff either), and if I so much as whimper, she makes such a fuss and the treats start flowing. It's a good racket over here, if you know what I mean.
Here's my problem: this summer we went camping in Mexico and one day this scrawny pip-squeak of a puppy followed us back to camp. My mom gave her some food (my food, no less), and I know the thing was hungry, but really, what a scene. You should have seen my mom fawning all over this little disaster.
Anyway, you can imagine the rest: that thing got itself a one-way ticket north and is now living the good life in my house. And guess who's suffering? Exactly. Not her. Me. Less cuddles, less attention, less everything. She steals my food, my toys, my spot on the couch and lately she's been getting into bed with us at night! My mom thinks it's all sooooooo cute and moves over to give her space! Can you believe it?
I've upped my efforts at adorability to show my mom that she doesn't need the other one, but she is smitten. How can I get things back to normal? How can I get my mom to see this thing for what it really is--a pain in the tail.
Thanks guys. I know you can relate.
Lovely Lula

Mickey: Can we ever relate. You should read our book, The Adventures of Mickey and Flea, about our early days together.
Flea: Talk about incompatibility. Mickey thought he could take care of the problem by turning me into a cat, because he said, dogs were insufferable. But he learned that we're really sufferable after all.
Mickey: Yes, but that was long after you took all my favorite sleeping spots and the human attention. I completely sympathize with Lula's plight.
Flea: Hopefully Lula is wise enough not to waste her time trying the impossible. Maybe, like you, she could find the new animal's talents and put them to good use. As you ended up doing with me, maybe I remind you.
Mickey: True, true. But I prefer the strategy of Banjo, our other dog housemate.
Flea: Please......
Mickey: Banjo dealt with the competition by becoming alpha dog.
Flea: No he didn't. I'm alpha dog sometimes. He just likes to beat me up when the humans aren't looking. And he's bigger.
Mickey: Precisely. There's your tact. Intimidate the bejesus out of your creature and we'll see how long she goes prancing about as the tiny queen.
Flea: Just remember to be adorably sweet when your human is around.

One hour later:
Flea: OK, Mickey has gone for his nap. I can level with you now that he's gone. When we got a 2-week old feral kitten, rescued by our teenage human, Mickey went beserk. He actually left the house for 3 months and refused to set foot inside. He'd stand pathetically outside the window and call for his food, making the humans bring it to him. Even his strike did no good. The humans were hopelessly, helplessly smitten by the little thing. I wasn't totally crazy about him myself as he really grabbed ALL the attention, but at least being a dog, and the old man of the house, it wasn't such direct competition.
Mickey finally relented when he realized he has no power over this. But don't tell him I told you. He's terribly humiliated. Eventually, the extra special attention mellowed out and we're all getting our fair share now.
Just hang in there. If your mom loved you before, she still does. And humans do get over their infatuations pretty quickly.