What are the most effective ways to document and analyze changes in a creature companion's behavior over time?

I'm curious what ⁢methods ‍people have found successful for tracking behavioral changes in their companion animals, especially over longer periods.I'm not talking about obvious things like "suddenly limping," but more subtle shifts in mood, activity levels, or social interactions.

Are you using a specific journal or⁢ log to ⁤record observations? If so,what kind of data points do you focus on? For example,do you track things ⁢like‌ sleep duration,appetite,play ⁢frequency,or interactions with other animals/people? I've tried keeping a simple spreadsheet,noting things like "less interested ⁢in fetch" or "more vocal at night," but I'm wondering if there's a more structured‌ approach that would be‍ more insightful.

Also, how do you analyze the data you've collected? Are there specific red flags you look for, or do you ‌primarily focus on identifying trends? I'm especially interested in​ hearing​ from people with older animals or animals with chronic⁢ conditions, as I imagine long-term ⁤behavioral tracking can be particularly valuable in those cases.