This is a story I wish I couldn’t write. I was diagnosed with recurrent breast cancer in May 2006. I had a low-grade cancer 14 years ago, treated with a lumpectomy and radiation therapy, but hadn’t given it much thought since. But that ugly old demon raised his head again, only this time much worse.

Since then I have had a mastectomy and 10 weeks (six more to go) of chemo-therapy, which left me bald, nauseated, exhausted and exasperated.

A primary concern is what’s going to happen to my two beautiful dressage horses and my amateur dressage career. Normal people can’t understand this; all horse people can.

Other setbacks have occurred that limited my showing: horse injuries, bilateral carpal tunnel surgeries and moving. This summer no bad things were supposed to happen. I have two rideable, good-tempered, extremely sound horses. I was riding both daily, finally making some progress and moving from training to first level! I was as fit as I’d ever been, considering I’m 55 years old.

Then the “Big C.”

It’s forced me to contemplate what my horses and riding mean to me. I showed hunters for 15 years and switched to dressage at age 50. There were always those days when going to the barn seemed like drudgery. But when I finally dragged my complaining body out to the barn, my mood lifted and I never wanted to leave.

I realize how important riding is to my self-esteem. I was never much of an athlete growing up, but now I have found a sport at which I can excel. It keeps me fit: how lucky I am to find an activity that I love and yet keeps me fit. Most women my age are reduced to drudge-like exercise programs that don’t give them a chance to be outdoors in the countryside, don’t give them big slobbery kisses and don’t beg for carrots. No soft knickers or loving gazes from those spinning machines.

It’s social. Sitting home day after day focusing on the side effects of chemotherapy is lonely, depressing and further depleting of body and soul. Even if I don’t ride, just hanging out at the barn lifts my spirit. Horse people don’t judge you by looks, age or amount of hair. We are one in our indescribable attachment to these wondrous animals.

Competition is still important to me. It’s even more important knowing that my age will limit my competitive days. We “vintage riders” often share a chuckle when we’re in the warm-up ring, worried and apprehensive about our turn in the ring, tired after our last-minute training and grooming, and realizing that normal middle-aged women are probably home preparing Sunday dinner, sitting in a comfortably heated spa, working on their yoga, or maybe golfing or playing bridge. They are not about to risk life and limb competing against teenagers.

In my career as a physician, a neurologist, accomplishments were never clear-cut. Helping but not eliminating someone’s pain or reducing the number of multiple sclerosis exacerbations were vague endpoints. I could appreciate that I helped someone, but there was no “victory.” Sometimes my most satisfying accomplishments went unrecognized or unappreciated by the patient. I may have diagnosed her exotic tumor, but all she knew was that subsequent lifesaving brain surgery left her with weakness and pain.

Competition is black and white. You clearly know if you’ve won or lost. It’s even better in dressage, where you get a written report of your test scores. Even though you’ve “lost” the blue ribbon, you may “win” recognition of improvement in movements on which you’ve worked so hard. Immediate feedback. Recognition. New goals set.

I’m still stumped, however, on why not riding feels so bad. I certainly miss the horses, the exercise, being outdoors and all the virtues of competing. I hate to see my high level of fitness go down the drain. I worry that the level of partnership I have developed with my horses will deteriorate. But this still doesn’t explain it all.

Where does this horse obsession come from? What do horse people have that others lack? I remember being very young and seeing my first horse: my attraction went far beyond the animal’s aesthetic appeal. It was more like love at first sight. This feeling has never diminished. I still pause and admire the horse in the field by the road, even if I’m on my way home from the barn!

I do get some peace of mind knowing that my two horses are in a wonderful barn right now. They are safe, engaging, personable and talented animals who have a waiting lists of good people to ride them. They receive excellent care, whether I’m there or not.

None of this has solved the problem of horse withdrawal. So, by sheer determination, willpower-and, yes-desperation, I’ve actually done two horse shows while on chemotherapy an have a third planned. I’m not supposed to be around germs. I’m not supposed to “overdo.” I’m not supposed to get any cuts or scrapes. But, I’m lucky. My oncologist is a horse person too. Somehow, on the back of a horse, all the fatigue and nausea seem to dissipate. My baldness actually allows my helmet to fit better, and I don’t have he aggravation of trying to get all those recalcitrant strands into the hairnet.

My “normal” friends think I’m even crazier than usual. My barn friends don’t seem to see or expect anything different. Their main concern always is, “How was your ride?”

And my brain and body are miraculously surviving this insult called chemotherapy much better. And maybe I’m starting to understand why.

Elizabeth A. Doherty is a neurologist and dressage rider who lives in Lewiston, N.Y.