Law of Karma for Animals

In few philosophies, it says karma is applicable only to humans and not to animals. Since, the animals do not have thinking capacity.

In any place, if there are many dogs, and if a new dog comes to that locality, then all the dogs shout and send the new dog away, as if their government has registered that street to them. If they behave like this, is there any reason why the dogs have to be excluded from the law of Karma? If the dogs are included in the law of Karma, is there any reason why the other animals should be excluded?