"We went out several times, and everything was going great," says Marilyn, a philosophy professor whose courses include animal ethics. "But one night Spider was coughing, and Travis got really mad because he couldn't sleep and he had to get up for work early the next day. But he was so nasty about it. I knew it was over then."

The canine conundrum didn't stop there. A few weeks later Jonas, another guy Marilyn met online, said, "I don't like your dog. He makes you look spoiled." The problem, she decided, wasn't with Spider -- he came with the territory -- but with her prospective mates. Jonas, too, was out the door, with nary a stop in the figurative doghouse.

Anyone who's surfed online dating profiles knows how important pets are to their owners. Singles frequently post pictures of their animals as an identifying characteristic or as a warning: "love me, love my pet." Either way, you'd have an easier time coming between Hall & Oates.

"I think the rule is, when you meet somebody and you want to change things about them, don't," says Rhona Raskin, a Vancouver-based relationship expert and former radio talk show host. "The condition you find the person in, with all their habits and accumulation of activities -- that's who they are.

"If they're a golfer they're not going to give it up, or if they're into karate 12 hours a week, they're going to continue. Really, the person's a package deal, and when you're a dog owner it's like, me, my dog, and my kibble. And anyone who thinks that's going to change is mistaken."

This bestial bonding goes beyond that of a caretaker/dependent. With people marrying later, staying single longer than ever before and living in small spaces in densely populated urban areas, a more lasting relationship takes root. Maternal and even paternal instincts need somewhere to go and strong, almost parental attachments form.

"The number of people who live on their own, either because they haven't found someone or they found someone and it didn't work out, is huge," says Raskin, who owns a large standard silver poodle. "That's partly because we live longer. It's a long life to be on your own in an apartment and pets are definitely a source of affection.