I want to say I am very sorry to hear about the death of your cat
But I also want to help you understand you are wrong to think the dog owner could or should be charged with animal cruelty and those who are blaming the dog are also wrong.
I worked in an animal shelter along with animal control. Yes, I made the video Pap posted.
People who let their cats roam freely are at least 50% responsible for their cats' deaths. Cats are domestic animals. They are not natural predators ANYWHERE. They can also be a nuisance to your neighbors.
If your cat entered the dog's yard and the dog was contained, well then, you are 100% responsible for the cat's death. This is why many cities include cats in leash laws, though rarely is it enforced. A dog killing a cat is not an act of cruelty. It is the dog's natural prey drive. Let's say someone has their pet hamster outside and the cat kills it, do you now say that cat is scum, evil, and made an act of animal cruelty?
Unless you can find the dog owner, and prove the dog owner actually commanded the dog to kill the cat, you have NO gas on the animal cruelty charge. Even if you find the dog owner, if the dog was in its own yard, then you can't even successfully charge them for the cost of the cat.
Pet owners need to act responsibly. And if you don't, then you need to understand, your cat's death was no one else's fault but the person who let the cat outside.
Outdoor cats life expectancy is LESS THAN HALF that of an indoor cat. Sure, there are really old outdoor cats, it happens, but its not very common.
Cars, animal attacks, poisoning (purposeful by spiking food with poison or accidental such as licking antifreeze off the ground), disease, and injury from falls/strangulation/etc all happen to outdoor cats.
No animal is evil. Evil means you are saying that animal has a consciousness similar to our own. Evil is a trait only seen in humans. A dog attacking another animal either by prey drive or territorial protection is natural. We bred dogs to take down game, do we say a foxhound is evil when it rips apart a fox? Do we say a cat is evil when it kills a dove? Obviously some of you are ignorant enough to think that and that is kinda sad.
I own 4 dogs and 2 cats. They all get along great. And yet, my dogs chase the neighbors' cats when they come into the yard. They once nearly caught it and it got away up a tree, just inches from my dogs' teeth. I have no doubt, they would probably injure or even kill a cat. My 3 big dogs all have prey drive. Two are shepherd mixes. Both breeds with prey drive. The other is a pit bull/hound mix, two breeds with very high prey drives. If they killed someone's cat, I would feel terrible for the cat and the owners, but I wouldn't blame my dogs nor myself. My dogs are in a fenced in yard, contained. If the cats come into my yard, I can't control that. That is up to the owner to deal with it. But because cat owners tend to blame dogs and dog owners for their own irresponsibility I can't tell you how many dog owners these days are going with the "shovel it and shut up" motto. Because of the ignorance going on right here in this thread. Apparently its perfectly okay for cats to kill rodents, birds and small reptiles, but when a dog kills a cat, its cause for banning dogs, killing dogs, and all out hate on dogs and their owners. One of my friends, both her dogs were STRANGLED TO DEATH after they killed the neighbors cat. They could never prove who did it, but after an unsuccessful attempt to sue the dog owners, a few night later, while his dogs were in the fenced in yard, someone called them to the fence, tossed ropes around their neck and hoisted them up. The scratches from their nails as they struggled to live were etched deep in the wood. This is what happens when people ignorantly think dogs are evil, they themselves do evil acts. The cat and the dogs died all because a cat owner felt their cat had more rights to roam than those dogs had rights to live in their fenced in yard.
If you get another cat, keep it indoors, it won't ever come in contact with that dog.