If there is any species-oriented preferences outside of taste and availability, it's purely out of a symbiotic relationship that they benefit from. Wolves aren't going to stop hunting deer unless the deer somehow provide additional sources of food that the wolves realize only exists because of the deer's help.
The source is in Russian from a zoologist who studied wolves: https://sovet.blocknote.info/articles/443/serdtse-volka-semy...
Some behaviors are instinctive, some are taught, some are the result of emotional conditioning (hence people taming and domesticating animals).
You agree with me.
And not just dogs. I have trained cats to become friendly to individual rats (I think instinct is too strong), and I have seen some species express either preference or disdain for other species. My personal analysis is that this has more to do with social and emotional conditioning, a true recognition of another animal as "friendly" despite not offering a symbiotic relationship, rather than directly as a result of behavioral conditioning with positive/negative stimulus.
I think a better indicator of the difference between us and pets is that we keep pets, and further, that we sometimes keep pets purely for emotional benefits. Incidences of non-humans keeping other animals as pets is extremely rare and seemingly limited to primates. [0] I think that says a lot about our psychology. But it's a little pointless to debate about whether other mammals experience meaningful emotions. They do. Meaningful emotions are actionable. That's why our emotions seem meaningful.
[0] https://bioone.org/journals/Neotropical-Primates/volume-13/i...
Isn’t that how humans operate as well? People keep pets that they get satisfaction from but we don’t eat our pets.
Then you have the debate of whether true altruism exists or whether people do even our most selfless acts because of the endorphin rush we get from helping others.