Pesticides are used to kill pests but it not meant to be used on dogs, though it will kill the pests on the dog's body. The pesticide will also harm the dogs population as it is toxic in nature.
Pesticide that would be dusted on the dog's population would be ingested by dogs and there are chances that dogs might die, not because of plague but due to pesticide.
If dogs are to be protected from fleas, there must be a proper vaccination for them because they will die early if pesticides will be used on them.
In fact, there is a Oceanic Carbon cycle! Carbon dioxide get absorbed by the ocean's surface from the atmosphere and then get converted into a dissolved inorganic compound and so on.
