How to understand dog flea attack?

You may have been noticing for a long time that your beloved dog’s fur is not as thick as it used to be. Getting thinner than before. On top of that, if you have a very cute cat, then the chances of the flea attacking the dog are much higher than the cat.
Sometimes due to our carelessness we pay less attention to them but we do it too late. So, we should always keep our eyes and ears open i.e. be more careful.
If we know some things, we can understand them very easily and quickly.