The many inconsistencies in the way humans treat animals are the subject of a new book being launched tonight, written by Melbourne University academic Siobhan O'Sullivan.
Her book titled 'Animals, Equality and Democracy' argues that the key to understanding why we treat some animals better than others is whether we can see them or not.
The more visible an animal is within the community, the more likely we are to treat it with kindness and respect, and protect it with laws and regulations.
But if it is out of public view, such as a meat animal or lab animal, that is a case of out of sight, out of mind.
For example animal welfare laws for hens in petting zoos are more comprehensive than laws for broiler hens raised for meat.
Siobhan O'Sullivan calls this the 'internal inconsistency' and argues that animal protection inequalities offend fundamental liberal democratic values.
"I've been interested in animals for quite a while. When I was doing my PhD at the University of Sydney, I was on the Animal Research Review Panel, a body set up by the New South Wales government to look inside research laboratories.
"As part of that work I started to think about the animals I was seeing inside the laboratories, animals that most people would not get an opportunity to see. And it started me thinking about laws, how we construct laws and how some animals do better than others.
"One thing that seemed fairly evident to me was that if we can't see an animal it's going to be very difficult to enforce protection for them. What I really wanted to find out was, when we construct the laws, do we favour animals we can see over animals we can't see.
"One of the things I can show is that the laws that regulate the lives of animals in zoos and circuses and places that are economic - the animals are there for an economic purpose but they are also highly visible - those laws have continued to improve.
"By contrast, animals in an agricultural setting who are also economic, the laws that protect their interests haven't improved as quickly as laws for high visibility animals."
In her book, Siobhan uses the example of a fictional rabbit named Bugs.
"Bugs is bought at a pet store and taken home as a present for a young boy. The boy is careless and leaves Bugs' hutch open. Bugs escapes and lives freely at the local golf course for a year.
"The manager then undertakes a trapping program to rid the golf course of rabbit pests. Bugs is trapped and sold, along with all the other rabbits, to a fur farm. The fur farming company then decides to move their business offshore and sells its remaining animals, including Bugs, to the local college where animals are used as part of an education program.
"Two years later the college decides to stop using animals in teaching and they donate all their animals, including Bugs, to a small local zoo. If all that was to ever happen to a single rabbit it would be an extraordinary journey! However, the key point to note is that at every stage of Bugs' life, the law would have protected him in different ways.
"When he was an agricultural animal the local animal welfare legislation may have ensured that he received food and water.
"When he was a research animal he may not have had any legal right to food and water, but the law may have said that he had to be provided with straw for nesting. As an exhibited animal he may have been legally entitled to live in a large cage, but when he was a feral rabbit he may have had no legal protection".
Dr. Siobhan O'Sullivan, Research Fellow, School of Social and Political Sciences, University of Melbourne, author of 'Animals, Equality and Democracy', published by Palgrave Macmillan.
By Bel Tromp, ABC Rural