i see that no one has disagreed or made an argument against this post. not surprised.
the whole problem with this argument is the fact that there is no difference morally between a dog, chicken, cow, pig, goat, fish, etc.
it's not like one is a living feeling thing and one is an inanimate object. they are all sentient living things. what's morally wrong to do to a dog is morally wrong to do to any other sentient animal.
Morality? Your version of morality hasn't existed in humanity, well, ever. For all of human history we have generally done what we needed to in order to support ourselves as a species. This is natural selection at work, and we are the dominate species. Arguments of human morality really don't extend into the animal kingdom very far, unless the action somehow runs counter to the role we have given the animals subservient to us (see domestication).
For example, we have given status to dogs and chickens (and other subservient species), each has had a role to play in the hierarchy. We actually created the modern dog through artificial evolution. They would not exist if not for our need for protectors. The first "Dogs" were just grey wolves that were either taken as pups or just befriended man for their own reasons (likely easy access to food). In return for taking care of them we trained "Dogs" to be protectors and warn us of danger. Today you have protector dogs and companion dogs (or a combination of the two). That is their current role, and it affords dogs a special status that sees us extend our morality to include them. Dogs have never really been seen as a food either. Also, it helps that dogs are seemingly more intelligent than other animals. Hell, some dogs can exhibit emotions or have personalities that are eerily "Human-like".
A Chicken's role is to provide sustenance in the form of eggs or meat. They have no other worth to humanity as a whole. Since they are lower in the hierarchy very few humans feel morally obligated to them. Historically chickens have been food. I would wager most humans see them as closer to plants than dogs.
Throughout our evolution the extent of which we cared about animals was "What can said animal do for me". If the animal had a role to play we domesticated them. If they didn't we tried to leave them alone (we failed at this a lot, see hunting things to extinction). I am sure some psychologist would say that early humans desensitized themselves to eating certain animals which we still do today, and I would agree with that.
Lastly, morality is something that is fluid. It is not set in stone. Generally morality is defined by a people's culture and that culture can be vastly different. I mean, there are cultures on earth right now where eating beef is immoral and others where eating dog is moral.
Living in the west, eating chicken is moral, and harming dogs isn't. If that bothers you, well, sorry but your feelings as an individual don't matter. Only the collective culture matters. That doesn't mean you can't have your own values, but don't feign surprise when the average person goes against them.
As for this video, as a dog owner and lover (she comes to work with me!), this video wasn't really that disturbing. I have had dogs fight me like that just to take a bath! That said, while I don't find it "disturbing", I don't think they had adequate safety measures in place and they should be fined for that.