A Quadrupedal Animal Character and a Bipedal Animal Character Together is Not Always Furry ConfusionTypically, a four-legged animal character and a two-legged animal character are at different levels of anthropomorphism from each other, with the former character being "non-anthro" and the latter character being "anthro." But this is not always the case. For example, a quadrupedal animal character and a bipedal animal character of the same (or related) species on the same level as or similar level to each other is not Furry Confusion as long as the two characters are capable of walking on two legs. Also, if a two-legged animal and a non-bipedal-stance-capable four-legged animal are treated on par with each other, then there is very little or no Furry Confusion unless the two animals are of the same (or related) species. So this settles not so much on the mere stance and that animals assume (bipedal, quadrupedal, or otherwise) as it does on how the animals are treated in the work.
Examples in Which This Situation is Not Furry ConfusionFilm
An Animal Character With a Pet is Not Always Furry ConfusionAn animal character who owns a pet is usually viewed as being Furry Confusion more than a human with a pet is. But, depending on the situation, this is not always the case. For example, it's technically no more Furry Confusion for a mouse or any animal beside a dog to have a pet dog than it is for a human to have a pet dog unless there are "anthro" dogs in the same universe. It's just Furry Confusion for any animal to have a member of its own species as a pet or even be a species closely related to their pet in some cases.
A Talking Animal and a Mute Animal on Similar Levels of Anthropomorphism is Not Furry ConfusionA Talking Animal and mute animal of the same species or of very closely related species is not Furry Confusion unless the two are at distinctly different levels of anthropomorphism (i.e., a talking Funny Animal or Civilized Animal and a mute Nearly Normal Animal).
Talking Animals as Opposed to Nearly Normal Animals Alongside Funny Animals Softens Furry ConfusionUnless the "anthro" and "real" animal are of the same species or of very closely related species, sapient, speech-capable, but non-anthropomorphic animals alongside Funny Animals and/or Civilized Animals softens the furry confusion in the situation.