Is there any way for consciousness to be measured? What does it mean to say that my consciousness is at a higher level than that of my dog, or that my dog is at a higher level of consciousness than a flea, or that the flea is at a higher level of consciousness than a rosebush? What are we measuring?

"Higher" and "lower" can be quite slippery terms, and your not likely to find philosophers using them in serious contexts. But one might say that different forms of consciousness can be distinguished by the different capacities they possess and the relative detail, discrimination, or complexity of those capacities. So, a form of consciousness that were capable of 600 shades of emotion might be described as more complex than one with only 2. A form of consiousness that possessed self-consciousness, a distinction between self and world, a capacity for memory, for imagination, for planning, for deception, for long attention spans, for causal reasoning, for symbolic thought, for invention, for metaphor, for memory, for mathematical reasonsing, for logical reasoning, for abstraction, for language acquisition, for a vocabulary of the size of the English language, for spatial conceptualization, for music, etc. might be thought of as "higher" than forms of consciousness without any of these capacities. ...