Since humans domesticated dogs some 40,000 years ago, we’ve become used to having animal on hand for food, companionship, clothing, transportation, protection, pest control, or heavy labor. So it’s natural that animals– both ordinary and supernaturally inclined– pop up in our fiction. I’d argue that they don’t appear enough, relative to their importance in daily human living. There’s also some patterns that occur in fiction featuring animals that should be brought to more widespread attention.
The first, especially in fiction set outside of Europe or the United States, is that we writers often forget the sheer diversity of domestic animals. We have tamed silkworms, llamas, cats, yeast, cattle, and a multitude of bird species. Yet the vast majority of fiction, particularly vaguely pan-European fantasy cultures, seem to feature an extremely limited ecosystem. In her hilarious and insightful Tough Guide to Fantasyland, Diana Wynne Jones points out that the average Fantasyland forest is populated by a single rabbit and the odd deer; on the domestic front, horses appear when transportation is required, with the occasional cat or bird of prey. In my opinion, both wildlife and domestic animals should be appropriate to the setting, culturally, ecologically and historically.
The Tough Guide entry brings me to my second point. Jones points out in her section on domestic animals that fictional horses have highly un-equine tendencies— they don’t get tired from galloping, refuse to cooperate with new riders, require special food, or display any horsey behaviors. (A notable exception to this is C.S. Lewis’ Narnia series). Similarly, other animals behave totally outside the norm for their species for no particular reason. Unless there’s an in-universe explanation– the cat is really a rogue witch serving out his punishment, the horse is enchanted so as not to tire out, etc.– animals should act normally.
Finally, there is a fixation on getting the protagonist a ‘cool’ animal as their pet or companion, even if that’s not practical or even plausible. Again, if there’s a good in-universe explanation (for instance, the owls in the Harry Potter series seem to be a magical genus unto themselves). Think about the ecology of that location, the background of the character, the logistics of keeping a particular animal, and how that animal would be useful to the character.
I’d love to see a greater number of realistic animals in fiction, where their presence both enhances the realism of the setting and advances the plot.