Go look at the ingredients on some of those super expensive boutique organic fertilizers that cost over $25 for a 20 pound bag. Then go look at the ingredients on a bag of cat food. The cat food has better stuff, and is cheaper, especially if you keep your eyes open in the supermarket where they often sell bags of cat food with a rip in it where maybe five percent of the contents spilled out for half price. You are really in luck if you can find the fish flavored bagged cat food on the clearance rack.

To compost?

If you use dog food to fertilizer you might just have every pest around in your garden. Plant cells and animal cells are very different. Plants would not really like that very much. Poultry manure is cheaper and will do alot more for your plants.

What will your end use of this Nitrogen source be? A catalyst for compost or to add to the garden?
Blood meal can be a better source of Nitrogen for a compost pile.
Whether garden soil needs Nitrogen depends on many things, but if the soil is in a good healthy condition it will not need any more Nitrogen.

Ummmmm, ok. I really don't know what cat and dog food have to do with using rabbit food as a source of nitrogen in my garden but ok. I just wanted something to add nitrogen into my garden at the end of the season. I don't have a space for a compost pile and I don't really want one because of all the critters roaming around (cats, raccoons, possum, skunks and the occasional hawk and fox). Thanks for any help given.

Nitrogen is a gas. The best place to get Nitrogen from is things that are alive -- their cells still have a lot of that gas captured.

You can plant legumes and cut them down halfway through flowering when the N is most available. The roots will have the N-fixing bacteria still in the soil, and the plants you cut down you can use for mulch. That's a double dose of N.

You can pee on your garden, as long as you're not taking any meds that could be in your pee.

You can add kitchen scraps into holes in your garden as you transplant, deeper than would attract critters.

You can add blood meal, but that would definetly attract critters.

There are lots of things you can do. I'd reccommend pee, pit composting, and planting legumes.

"You can add kitchen scraps into holes in your garden as you transplant, deeper than would attract critters."

Yes!!!My fav;)

"Nitrogen is a gas"

Right. So is hot air. Which means what the OP actually is looking for is a dense source of nitrate. The fishy cat-food would be that. The rabbit food less so but not bad.

Urine mixed water water to urine 10:1. It's free and available. Cheap dogfood is good, but urine is easier.

You say you live in the city with no feed stores close....are you sure?
Here is a link to locations, by state, for Tractor Supply Company, commonly known as TSC....

http://www.tractorsupply.com/StoreByStateView?storeId=10551&catalogId=10001

I purchase the 50# bags of alfalfa pellets there! Just don't get any of the cubes...they take forever to break down!

Well, yes, it would be an OK source of nitrogen but an expensive one, and not a very high one at that. I have pet rabbits and they are required to eat a diet much lower in protein than a human's diet. And it would go against some organic principles (think of the energy that goes into manufacturing pet food). Use stuff that would be thrown away anyway, like seed meals, alfalfa meal or corn gluten.

I agree with ga karen on TSC, always near the Walmart here.
Off subject a bit, a pot of the plant comfry will give you all the compost tea you will need.

If u live in the city, find a starbucks. They give away free nitrogen in the form of coffee grounds.
Grounds for Your Garden

Legumes rotated with your other crops will leave behind a good dose of nitrogen. Southern peas (blackeyes, etc.) in summer, hairy vetch, Austrian winter peas as a cover crop in winter. This will help your nitrogen levels along with animal manure.

Here is a link that might be useful: In the Charamon Garden

The coffee grounds have lots of oils. Water will sheet off of them. You'll have to screen them (sometimes there is detritus or other stuff in the bags) and at least halfway-decompose them.

Legumes will only leave behind N if 1) the necessary bacteria already exists on site and 2) you cut down the Legumes in time. Maximum amount of N fixed into soil-nodes (where the bacteria reside) is usually about halfway through blooming.