Should you breed animals?

When I was a kid I had always wanted to have a zoo of animals that I would run.  Maybe because I wanted to charge admission and make money (I was a bit of a businessman as a kid) but I really liked the idea of taking care of animals.  My first "pets" were slugs and snails in transparent containers with plastic wrap on top, poked with air holes.  I even had some snail babies; tiny translucent little things.  Later on I had fish, a hamster, cats and a dog.  I would look through pet stores in envy at the reptiles and other interesting animals (hedgehogs, chinchillas, ferrets!) though I didn't quite have the income to support them.  Now that I have the money (though with less time) I was thinking about whether it might be fun to have some animals and potentially breed them to make some money on the side.  My cousin actually breeds reptiles so I knew this wasn't completely insane.

Doing some preliminary research I found that there was no shortage of people with the same questions about breeding and there many different options for the types of animals.  I live in the city so livestock is out and I was thinking I wanted to keep the animals on the smaller side as space is at somewhat of a premium.  Guinea pigs, geckos, turtles, mice, fish, hedgehogs.  All seemed like potentially interesting candidates.

One of the common things I found is that if you are wanting to breed animals you'll need multiple enclosures to separate the different animals at certain stages of the process.  You'll often want to separate the female after she's pregnant and the young after they're born.  You may want to have the males separate from each other as they may get territorial as well.  It's important to separate animals that are about to give birth because it's possible for a female to get pregnant again shortly after giving birth which isn't good for her health.  The females should often have several months rest before breeding again, which emphasizes the patience you'll need to have in breeding animals.

Common things that I seemed to keep finding in my searches was that for some animals it just doesn't make sense to breed more of them.  There are apparently many guinea pigs without homes already so you're going to be hard pressed to give them to good homes.  Pet stores usually don't give great prices from the animals or won't even take them at all.  I also found that people are very wary of other people wanting to start breeding animals purely for profit.  They know about the "puppy mills" and people in it only for the profit may take shortcuts and not treat the animals with respect.  What I often found repeated is that you are probably not going to make much if any money from breeding animals.  Most people do it as a hobby and they do it because they enjoy it.

In the end I came to the conclusion that I don't really have the time at the moment, but I may consider it for fun in the future.  Hens can be kept in backyards in Vancouver now, so that could be a future source of my eggs...  However if you're going into pet breeding thinking that there is a profit to be made, remember it's probably not the case.