The dream would have a symbolic meaning that pertains to your life at the moment.
Having observed a cat that went into the water and swam, can be seen as your ability to face challenging situations at this time in your life. Even if there may be some risk/danger involved, you're open to exploring new territories and making it through. Here the swim or drawn analogy can apply. In order to move onward, you have to "get your feet wet."
The fact that the cat seemed willing to go in despite the water being cold, indicates that you're up for the challenge and ready to do whatever it takes to either resolve a situation or get one of an unhealthy one. You're open to do whatever it takes now.