Justifying social divide? 'Dogs too have caste system like we humans, it's natural'

I have never had any pets, nor am I very comfortable with them. Frankly, I don't know how to play with a pet dog. I just sit quietly whenever I visit someone and see their pet dog trying to lick my feet. While I am told not to worry, I still choose to be a little careful, avoiding touching the pet.
During my childhood, I recall how street dogs once ran after me, making me feel terribly fearful they would bite me. (It's another thing that the dogs were shooed away by people around.) Later, I experienced the real fear of a dog on two separate occasions.
The first time was in the early 1980s, when I was with Link Newsweekly as chief sub-editor. My editor fell ill, and those of us who were on the desk decided to pay a courtesy visit to Sitanshu Das, who then lived in a government quarter allocated to an accredited journalist.
It was winter. Das was sitting on the lawn outside his house on Lodi Road in Delhi. His big pet dog sat next to him. As we approached him, I decided to stand a little away and asked him whether the pet would bite.
"I don't know. He hasn't bitten anyone recently," Das replied, smiling. Yet, I felt uncomfortable and wanted to get away as soon as possible.
The other time I felt fear was in the mid-2000s when I represented The Times of India in Gandhinagar. I often came down to Ahmedabad and invariably visited my cousin at least once a fortnight. They had a pet dog they called Rex, who, while recognising me, would lick me, my clothes, and sit next to me even without being called.
One day, after visiting her, we decided to search for a Kentucky Fried Chicken outlet that my children claimed they had spotted on CG Road. We parked our car, a Fronte, and started looking for KFC, but couldn't find one. On our return, a street dog, perhaps smelling my clothes, started barking at me and then bit me on the leg. I had to take injections for several days as a precaution.
Be that as it may, the main reason for writing this blog is a neighbour, a very amenable person, who has a pet dog that seems to me to be very ferocious. We were sitting in a group, and he, along with another neighbour who also has a pet, started giving the minutest details about their dogs—how they behave, what they eat, and when they are likely to attack or bite.
One of them told me that dogs have their own territory and know which dogs to bark at and which to ignore. They like certain types of smells, which make them decide their likes and dislikes.
"I don't like others touching my pet," he said, "so I tell anyone who tries to come near when we go out that I wouldn't be responsible if it bites."
What he told me next stunned me: "They know some breeds they would befriend and dislike other breeds, whom they consider enemies and may even run to bite. They have their own caste system, which they seek to preserve passionately. It's the same as we humans, who are similarly divided into castes and regions."
I couldn't resist asking whether he considered such a situation natural. His reply was in the affirmative.
Then I dared to ask a question that must have sounded presumptuous to him: "So, what do you think? Are we following the caste system like these dogs do? Should we follow the animal way of life?"
He looked at me, awestruck, seeming to realise that he had perhaps made a mistake by comparing the so-called caste system of dogs with that of human beings. Refusing to reply, he said instead, "It's quite some time that we've been talking... Let's go!"
An internet search on dog behaviour tells me: "Dogs definitely seem to have a sense of who to bark at and who to ignore, but it’s not always as straightforward as it looks. They use a mix of body language, scent, and social cues to decide how to react to other dogs," picking up on things like "confidence, fear, or aggression in another dog."
"Sometimes they’ll bark at a dog that seems threatening or overly excited, and stay quiet around one that’s calm or non-threatening. Other times, they might bark just because they’re feeling playful or trying to get attention," the search says, adding that it’s also shaped by their past experiences. "If they’ve had a bad encounter with a certain type of dog, they might be more likely to bark at similar ones."
The next line underlines: "Kind of like how people can develop instincts about who they trust!"