In World of Fizz, the character Dawn, who is an anthropomorphic cat herself, adopts a non-anthropomorphic cat. Other non-anthropomorphic animals are portrayed for comedic purposes.
Justified in thosetwo trip from Schlock Mercenary where a genetically engineered ("uplifted") elephant from the protagonist's mercenary company try to interrogate a uplifted one hiding in a circus full of non-uplifted elephant, of course since he must keep this secret his intention are misinterpreted.
In the same comic, a cat character has numerous pet cats, and says that it's instructive to have a pet with all of your instincts and none of your higher thoughts.
Explained in Freefall: Florence is a genetically engineered creature based on wolves. She occasionally deals with more mundane canines. There's another sequence that explains how she originally resembled a normal wolf cub, but had to adapt to bipedalism as she matured. Talk about growing pains.
Every creature in Kevin & Kell is anthropomorphic, down to the bacteria. The confusion here mainly has to do with their size. Some of the insects we see are the size of the main characters, about human sized. Others are tiny, as you would expect from insects. The real confusion sets in when we see examples of both sizes from the same species, like the moths.
Lifespans are also massively screwed up — just check out this strip. For those not knowing, a fifteen year old wolf in the real world would be either dead or in their dotage. One day, however, is about right for (adult) mayflies.
And then there's the morality of carnivorous people; apparently it's alright for them to kill herbivores, even though they're quite sapient. In fact, the one of the main foci of the strip is carnivores and herbivores getting involved in relationships, to the point that the eponymous characters are a married carn/herb couple — and yet there's no problem that Kell's job is to kill massive amounts of herbivores.
Apparently murder is acceptable as long as it's part of the natural preying process (the incident that granted everything sapience is pointedly established as having done nothing for morality). This means that predator species can, literally, get away with murder, while the same act is criminal for prey species. Kevin's father is in prison for killing a carnivore (which admittedly gave him a badass cred). No one seems to think this is unfair, either.
Exterminatus Now made it clear very soon that regular, non-"furry" chickens exist. However, it also confirmed that "furry" ones exist too, very anthro, very sapient, and very murdered.
The creators have said that there were plans to create new nonintelligent animals for the universe, but they never got around to it.
Another comic has one character use the Stock Phrase "Do bears shit in the woods?" which leads to a discussion which culminates in, "Also, isn't our boss a bear?"
Not to mention, Lorenda is at least Part demon. It has also been established that she has a tendency to eat the people who piss her off, which is why Jyrras brought her back to Lost Lake.
Achewood, for all its oddity, partially averts this — Roast Beef's pet, Winston, is an AIBO (a robot dog).
On the other hand, Ray (a cat) tends to address Roast Beef (also a cat) as "dogg", the irony of which has never been remarked on.
Dogs are regarded as animals by the characters; see the strip where barking dogs keep Molly and Roast Beef awake, or the one with Ray's "Magreaux Dog." Despite this, dogs have been shown talking on a few occasions. It could be that cats in the Achewood universe simply look down on dogs and refuse to consider them equals, much like in real life.
You Say It First averts this; the pets shown have been Brants (a creature vaguely similar to a rabbit or cat, with blue or purple fur; not the Real Life goose) or fish.
Sequential Art depicts a world mixed with humans and anthropomorphic animals... sans Leonard, the Team Pet who is just a regular platypus yet acts somewhat human. A perfectly regular platypus with an as-yet unexplained three-foot poisonous barb that occasionally bursts forth from his upper spine, in place of the barbs on the back of his... Flippers? Claws? Duck feet.
S.S.D.D usually averts any mention of species, but mentions it at least twice in relation to an affair between two characters of different "species" (which is apparently considered an unusual fetish even though it's common amongst featured characters).
Las Lindas eventually explains that their anthros are aliens that happen to resemble earth animals, but before that revelation, it's shown that one of the two cow-anthro characters runs a milk factory, and the other runs a dairy farm. To add to the confusion, no non-anthro cows and almost no non-anthro animals have been shown.
Mewsli from Tiny Kitten Teeth is an anthropomorphic cat who has a pet regular cat. Lampshaded in an early comic when he brings the pet cat on a bus and someone thinks that it's his child.note Which just raises further questions, if they can't tell furries and regular animals apart.
Appears in Pandect, where there is a clear difference between animals with souls and the ability to wear a human form (Aces) and animals without souls. Aces sometimes have a sense when a human or animal is another Ace, but they do not know for certain until the other Ace reveals it.
Actually very well avoided in Jack — Their anthros were originally created experimentally by humans, first just rabbit-people, then, presumably, all species. The reason we don't see humans in their world is because they killed them all. Non-anthro animals remain exactly as they are for us. There is the strange matter that the furries can interbreed, and become strange mixed-species creatures, yet almost all of them appear to be one pure, unmixed species.
The most popular explanation for the interbreeding is having a common base in the form of human DNA with some extra bits from other species spliced in. Enough to give the distinct appearances, but not enough to create true separate species.
Variation in Bar D: It's established that all animals exist in both anthropomorphic and non-anthropomorphic varieties . . . which leads to Vas being bewildered when he sees a human, because he can't even begin to imagine what a non-anthropomorphic human looks like. Shelia's attempt to explain how anthropomorphism works just leads him to believe that humans are "empty shells, devoid of all existence".
A sentient alligator in Vinigortonio in order to avoid getting headshot by Platypus's pendant attack uses the Croc-o-style Sniper set... which is made from a skinned and decapitated crocodile...
In Fruit Incest, Molo and Zeke are both surprised to find cheetahs at the zoo, but never question why none of the other cheetahs are anthropomorphic.
In Concession, Artie and Melusine go fishing and then cook their catches for dinner.
Artie:(about to eat fish and crab with Melusine) This feels weird. It's like I'm about to watch cannibalism. Melusine: Dolphins are mammals, Artie. Artie: I know! I know. But it's still weird, you know? Melusine: You know what's weird? Furries that have dogs for pets. I think that's weirder than anything we do.
Rank Amateur has GELF, like Felix and Guardian, but also has normal animals. This is because GELF are Genetically EngineeredLife Forms, creatures who most commonly share DNA with humans, but also with other creatures. In some cases, a form has been made through Computer Aided Design whose DNA is entirely made up specifically for that form.
Precocious: One of the many reasons Chrispy made all the characters either cats or dogs was to avert this.
The comments for 'Normal Clothes' raises this point; when Principal Blessure decides to dress up as Cruella DeVil it was theorized that in the Precocious world that the movie is about a woman who kidnaps children (of a specific race) in order to skin them and wear their pelts. In the real world, family movie; In a furry world, horror movie.
Alexia (a human) makes a rather nasty faux pas around Thisisa (a raccoon) in thisCats N' Cameras strip. (Warning: link SFW, but most of the rest of the comic NSFW.)