What makes a pig or chicken worth less than a cat or dog?

First question: a thing is "worth" what people will pay for it. I looked at the prices (on only one site) for pigs and the maximum I found was £300.00. It's possible to obtain a dog or cat for, literally, nothing. Obviously, some people are willing to pay a lot more for a dog or cat of a specific breed or bloodline. Generally though "farm animals" are MORE valuable than pets. In the case of chickens, they are not genarally kept as pets and their value relates to what they (as meat) or their eggs, are worth on the open market. Eggs and chicken are cheap to buy in shops therefore chickens are relatively cheap. The last chickens we bought cost around £5.00 each although I came across similar ones available on the internet priced at £10.00.

Second question: the two clauses you have on each side of your "but" aren't related. Most people "wouldn't dream" of hurting a cat, dog, chicken or pig either. You could just as logically ask: "Most people wouldn't dream of pulling the heads of a clump of bluebells or daffodils but will happilly eat other plants".

People eat the flesh of certain animals and parts of certain plants because, in their society/civilisation/culture they are considered "food". In some societies dog, horse, alligator, ostrich, snake and even rat are considered "food".

I disagree with your opinion that pets are "more important" than animals used in the production of food, in the same way that I would disagree with the idea that a houseplant was "more important" than plants such as corn, potatoes, peas etc. grown as food.

I cannot believe that you are actually seeking information; surely you know these things already?

I also wonder what this question has to do with "Entertainment and Music".

Meat is a relative thing depending on where in the world you are. In China and Korea, cats and dogs are food.

Because there are billions of chickens and pigs in the world and numerous amounts are killed daily to be eaten; people who eat meat don't think much about eating pigs or chickens but many do care about eating cats and dogs because they're common house pets (most people would feel uncomfortable eating something the same species as their pet) and cats and dogs aren't something many people eat on a regular basis so they may feel uncomfortable.

Humans have developed relationships with cats and dogs . This gives them a responsibility to them. They do not have a similar history with other animals.

Social conditioning. In china they view dogs like pigs and chickens. Hindus(?) wouldn't dream of eating a cow.
Overtime you develop a bond to something if you are not a robot and display empathy.

Plus eating predators is not very healthy?

They're cuter???

Dog and cat is domesticated, pet
Pig and chicken is food

Cats and dogs taste awful. Cats are nothing but bones and dogs stink.

Meat is murder