I work with childless, husbandless women that refer to their dogs as their children (and one of them bears a striking resemblance to her pet). These freaks take off for days when their “children” die (regardless of what’s happening in the real world), and are always vocally opposed to any company picnic.
They are the last vestiges of post-Christianity America, and are being displaced by Latino immigrants and those Americans that value children. In fifty years all that will be left are a string of abandoned pet cemeteries. FWIW, I love animals so much I think humans should leave them be; my wife’s family is Spanish, and they don’t have a word for “pet”.
Perhaps your wife has a limited vocabulary:
“...a pet in Spanish can be referred to as una mascota (the same word is used for a mascot, such as an animal symbolizing a team), un animal doméstico (the adjective doméstico can also be used to mean “pet” as an adjective, as in un perro doméstico, a pet dog) or un animal de compañía (again, the phrase de compañía can be appended to an animal’s name to indicate it is a pet).”
http://spanish.about.com/od/spanishvocabulary/a/pets.htm
Also, I'm half-Cuban and my dad's family here and in Argentina refer to pets as "mascotas". My husband is from Central America and they don't have a word for 'pets'.