As it can be inferred from the title, Pink Hills is technically a work of historical fiction. In any case, it reflects all of the events that happen in our human world, despite being set in a universe with anthropomorphic animals. This comes with the trappings of racial, ethnic, and cultural issues attached to these events, as it is hard to separate these elements from historical events.
This brings up the question: how does racial/ethnic coding work in this universe?
Since this is an American-centric concept, the United States' classifications of race will be used, as found here.
Simply put, a species of animal is ethnically coded based on their native species range. This means that for the most part, no two characters of the same species are necessarily coded as the same race and/or ethnicity. For example, red foxes in this universe can be racially coded as white, Native American, or Asian, since their species range is within those areas of the world. This leads to the situation of, say, Fitzgerald being coded as white and being of Russian descent, while Dale - Lawrence's boyfriend - is coded as being Japanese, and therefore Asian.
Some species, on the other hand, have limited racial and ethnic coding. For example, Red pandas can only be coded as being Chinese, since their geographic range is limited to a small area in China. This does not necessarily mean they are from that specific area of China, just that they are of Chinese origin.
Certain domestic pet breeds came around because of social standards that existed at the time, which affected who they got into relationships with.
Speciesism exists in-universe. Depending on where you are in the world, speciesism, racism, or something else may be a greater influence in discrimination. In America, speciesism is not as big of an influence as racism. This doesn't mean it's not there at all.
Certain species throughout history were more likely to be enslaved for their resources or to provide labor. Animals we often use for labor, such as cattle and sheep, were more likely to be subjected to this. Some would be enslaved specifically because of what resources they would provide, such as sheep for their wool and cows for their milk. In other cases, it would be strictly for manual labor and other forms of servitude, such as with horses and bulls. Sometimes it was both.
Some animal species will have more prevalent stereotypes than others, and this may play into varying levels of discrimination. Sometimes this will intersect with racial/ethnic discrimination an individual experiences. These stereotypes can be based on the existence of their species, a result of their species' positions in society throughout history, or a mix of both.
For example, rabbits tend to be stereotyped as having a higher sex drive, living in larger families, and being war fodder. Domesticated sheep species tend to be viewed as being less capable of leadership. These stereotypes are mainly based on the existence of their species.
Horses are stereotyped as being more "suited" for blue-collar labor work, which is a result of his species' marginalized past. In addition, horses are more subject to oversexualizaiton, which is based on their merit existence as a species.
(An example of these stereotypes intersecting with racial dynamics are black-coded horses in the USA being more subject to these views, due to the horse species' past roles in American slavery, and pre-existing black stereotypes, specifically the mandingo stereotype.)
An individual will likely experience a range of consequences for deviating against these expectations, ranging from microaggressions to systematic discrimination. These consequences may be downplayed or amplified depending on their race and/or ethnicity.
Mixed-species individuals are more subject to discrimination, and the severity of it increases the more obvious it is they are a mixed species.
There are implied to be non-sentient animals within this universe which act as substitutes for animals in our universe. For the most part, this is not replaced with anything. These are called "feral" animals. It is much like how a specific species of monkey evolved into humans, but there's still monkey species which have not evolved into humans.
An animal is either anthro or feral, never both.
Most animals can grow hair on top of their head, while others cannot. Wigs exist in-universe.
Animals who can grow hair tend to be species with longer fur. Their hair grows longer on top of their head, and its natural color is the same color as their fur. From a young age, their hair is trained and styled to grow a certain way. It often ends up getting dyed a different color. There is an expensive surgery that can permanently dye the hair at its roots, which is a highly revered thing to do, and a procedure few can afford.
Aside from the tail, individuals are expected to keep their fur elsewhere on their body trimmed to an appropriately short length, which can be seen akin to shaving body hair.
Any historical figures that exist in our universe also exist in this universe.
The baby formula industry is a very profitable one, due to the heavy reliance on it, and the amount of variation in products.
During the transatlantic slave trade, animals such as water bison, African species of domesticated cattle, lions, elephants, etc. would be the primary targets.
Cows are usually pressured to work in the milk industry, and face social and industrial barriers for not doing so. Cows often find it harder to get jobs anywhere else besides the milk industry, especially in the time period this concept takes place in. Cows who aren't in the milk industry end up donating their milk in a similar manner to people donating their clothes, or selling it on their own.