Hello Gloria, I'm Dr. Deb.
I recently came online and see that your question about Minxy hasn't been answered. I'm so sorry that you've had to wait for a response,but if you still need assistance, I'd like to help if I can.
The answer to your question might depend on several things such as does she go outside? If so, then she may have experienced an injury or trauma of some sort which caused the hair loss that you're seeing. Even if she's inside, if she got herself lodged somewhere that she had to pull herself out, then she might have scraped her body in the attempt.If that's the case, then the hair should regrow in several weeks.If she's been over-grooming or licking her body excessively, then parasites (fleas or mites) might be responsible. Other causes of over-grooming include allergies to such things as pollens, grasses, dust mites or mold to name a few examples although she's a little on the older side for this unless you've moved recently or there's something new in her environment to which she is now being exposed.Even cats with food allergies can over-groom or excessively lick their bodies although they also tend to be itchy around their neck/head.If you think that this might be the case, then I can provide some over the counter treatment options for you.Cats with spinal or orthopedic pain will sometimes overgroom themselves in this area. I can also provide some treatment options for you if this is a possibility.I'd be more than happy to provide additional information if necessary.
I hope this helps although, again, my apologies for the delayed reply. Deb
Many thanks for kindly answering my question about Minxy (esp. on Christmas Day!) . She doesn't go out much, preferring to peer out when the door is open, with occasional forays into the garden. This patch appeared suddenly, and then doubled in size in a few days. It has not gotten any worse since then (a few days ago). How would I know if she was excessively grooming? She sleeps most of the day, waking to eat, toilet and have a walk around.