I'm the same way as Lies. I never thought that I could love a dog more than I loved Keeta.. And conversely, I was also worried about another dog displacing Keeta and taking all my attention. Now that I have Gryffon, he is my heart, but while Keeta is very independent and has her own agenda in life, Gryffon only lives and breathes to please me. He is always with me, sleeps on the bed while Keeta, by her choice, sleeps on the floor. It is a lot easier to love and lavish love on a dog that is cuddly and responsive and always trying to engage you. But I can't imagine not having Keeta with me. If I go somewhere with only Gryff, something is missing. I just don't enjoy walking one dog alone as much as I enjoy walking the two of them together.
About a year ago, Keeta spent the day at the vet for a minor procedure, and I felt completely lost without her around. To me it does not feel like loving one dog differently than the other, as much as loving the two of them together, if that makes any sense?
Gryffon is a joy and a pleasure, but the joy and the pleasure seems fuller and more complete by having Keeta (and all her challenges) as part of my everyday life.