Planning on starting a niche pet supply shop...thoughts?

It's cute but it sounds as if you're selling pig food.

Indeed. If I searched for "organic dog food" and a place called The Orange Pig showed up, even as the first hit on Google, I would probably scroll down to the second hit, especially if its name were something more likely to be dog-related (or less pig-related).

Before we get too far ahead of ourselves:

1.) Download and write up a business plan (it feels business schoolish, but it helps clarify your mind).

2.) Find a good small accountant (there are legalities involved).

Business plan is currently under construction. Various things are being tended to when I'm not cleaning monkey poo or not completely knackered from cleaning said monkey poo

I know the name is a bit obscure and that darn childrens clothing company is using it as well, but that's one thing I'm set on and am willing to work extra hard to get my orange pig to be THE orange pig 

In a world of 9 billion people, almost everything is being used at least once or twice....

If you're willing to be a bit flexible on the name, www.thechestnutpig.co.uk (and .com, .net, .info, etc) are all available.

Chestnuts can be pretty orange in colour.

I know you really like your name, but as a business woman I would really invite you to re-evaluate it...

Just throwing this out there, it's a dot com in the US but not in the UK.  This name would make me click on the website:

The Healthy Pet

That's not to say that The Orange Pig wouldn't be just as successful, but it'll give you a bit of a steeper hill to climb.  I don't own pigs, I own cats and would think a pig website would be more for farming animals and less for domestic pets.

Not trying to knock you down, you have a brilliant idea.  Just a bit of food for thought on the name.  Branding is incredibly important and should not be taken lightly.