Oh dear, so sorry to hear this.

Do not blame yourself, and do not blame the dog. I am sure it was not intentional. But because resource guarding can be a serious issue, you may want to search the "nothing in life is free" dog training regimen.

Basically, no free feeding, you eat before the dog, and the dog has to wait until it is given food or anything else. It's annoying at first, but can help train the dog out of this behavior.

Rest in peace little kitten.