If I remember rightly, the chondroitin can also come from chickens (?).
While I am in theory in favour of speaking to one's doctor about natural products, in practice, I've found it's of very little use. Let's be honest here; unless you're VERY lucky in your doctor (and many of us don't have much choice, either because of insurance issues, or, as where I live, because of a shortage of doctors) you probably won't get one who's either 1. sympathetic or 2. has a clue.
Doctors are busy; I know some doctors. They'd like to have time to do research on these things, but most don't. That's why so many of them will toss you the latest and greatest drug -- they've got the handy glossy package and free samples right there conveniently on their desks, and they DON'T HAVE TIME to research the available alternatives.
Most doctors are also conditioned, by training and possibly inclination, to seek a "magic bullet" drug remedy for PROBLEMS, rather than a holistic lifestyle change to, hopefully, PREVENT problems. Natural remedies tend to require more of a whole-life change in order to really work properly.
It's not that I'm against the allopathic medical profession, but I think if one wants to know more about natural therapies, conventional doctors are not the ones to speak to, and many will be very negative and dismissive, without evidence to back things up. Certainly if one is already on, or being placed on, some conventional drug, one should make sure the doctor knows of any herbal remedies one is taking -- but I believe personal research is the most reliable way to gain information, or speaking to an appropriate natural therapist trained in an accredited program.