While you are waiting for an answer you can read this earlier thread which is close to this topic, where u/LockdownSurvival discusses how the perception of dogs have changed in Western and Near Eastern history

I use markdown when writing so the format may appear a bit odd:

Is this unique to Western culture or are there other cultures which show similar adoration?

It is worth noting dogs have existing on a long spectrum of time alongside the human race yet have not always been "mans best friend" in Western Culture. Similarly there are places where they once were mans best friend (or higher levels of adoration!) but have since fallen out of high regard, and locations in the western world where they once were objects of disgust before coming into high regard (this specific scenario in the christian-european times as u/gynnis-scholasticus said can be read here)

This same time, western culture in its modern sense has not always existed, nor the high regard. It does make it hard to compare histories as much of western culture is only 200 years old. Where do we draw the line on current culture to past culture?

Also recognising limitations that much of what we know is records from the times and we can only make assumptions as to the culture. Who's to say 5 centuries from now people won't assume the western culture loathes dogs from the number of dog legislation and complaints on barking? The more time passes and records are lost, the smaller the claim we can make to know the culture and how it has changed or remained unchanged. Much of our records rely on the written and illustrated record. Those cultures where the records are verbally passed down are harder to compare (including language barrier).

And last, noting that the definiton of humankinds best friend has no solid definition. Is it those who allow the dog to sleep indoors? Those who work their dog in a task that aids them? The use of dogs to improve on jobs? When the first few dogs started working with us? It is a very broad term to try and measure against but I will give it a shot.

I hope these following examples of positive regard illustrate that it is not so much limited to one culture in one time:

Rome: Aristotle (4th century) on dogs: "the dog is clearly honorable because being without a dog is most dishonorable."

Greece: Arrian (2nd Century) in his Cynegeticus outlines in great detail his favourite dog, praising her swiftness, cleverness, hard work, agility, gentleness, affection, and devotion to her human companions, and ability to communicate. (Her name was Horme (a word whose basic meaning is "rapid motion forward").

Greece: Nikephoros Basilakes (12th Century) liked dogs so much he wrote a book on it, "In Praise of the Dog" although he is critical of those who would give the dog a deity status. He was much in favour of dogs having souls.

Italy: Leon Battista Alberti wrote a comedy-eulogy (a roman style for funerals at the time) for his dog after it was poisoned. This eulogy included human-custom recognition of the dogs ancestors and examples of their friendship.

Early Islam: I note I am not Muslim in this, so here we are recognising texts of old demonstrating positive-culture to dogs and as referred earlier, times and interpretations do change. The Qur'an refers to dogs three times, in a positive light.

1. sura 18, "The Cave," in which verses g- 26 recount a version of the seven sleepers of Ephesus.Here we are told that while the young companions slept soundly, "their dog stretched out its legs across the entrance [of the cave]" ( Q 18:18).
2. sura 7, "The Heights," which says, "[The unbeliever] is like a dog. If you attack it it lolls out its tongue. And if you leave it alone it lolls out its tongue" (Q 7:176).(The regard here is that dogs are neither evil or problematic, but ignorant)
3. sura 5, "The Meal," that wild game caught by "trained hunting dogs" is licit and therefore acceptable for Muslims to eat (Q 5:4).

It does raise the point, how do we define what is "mans best friend" based on records prior to the existance of the terms. Is it those who regard the dog on level with humans? Those who work with a dog in partnership e.g. the hunters and herders? Is it those who specifically claim the dog is their best friend, yet may whip them from their hand to obey (happening even today in western culture, this is not isolated to history).

(continued in next comment)