This one makes me feel awful.

So your neighbour lets his dog in your house and the dog eats the cats food? He's an idiot because dogs can get really sick from eating cat food all the time and visa versa. ..not to mention that your neighbour is an ignorant asshole to be letting his animal go into your home when your not there, without your permission. It sounds like it is time to seal up the cat door to prevent this from continuing.

Maybe your neighbor is going through rough times and can't afford dog food talk to him about it and if he his lend a helping hand :)

poor kitty. i know u can buy pet doors that you can like "lock" while you're give. I've seen some where you slide down like a metal plate into place while youre gone. Another less expensive solution is to place the food up somewhere high where the cat can get to but the dog can't.

Don't get it?

Set up a camera to catch him in the act and then call the police. Also, cat food is toxic to dogs. Personally, me and that neighbor would be having some quality chat time about how I will face **** him with my foot if I catch him at it. /loves my cats

Poor cat! I'm so sorry. You definitely should sue! That's awful. I hope your cat's OK.

There are pet doors which only let in your own pets.

I'm sorry OP, hopefully you can reinforce the doggy door. Your neighbor shouldn't have a pet if he can't feed it and has his dog steal your kitty's food.

Sounds like you need a microchip cat door so that no other pet can get through!