She was brought in to see me at once: after examining her carefully, I explained to her owners that she had suffered a serious spinal injury.

I took a series of  X-ray pictures, to identify the precise nature of her injuries. The first, survey radiograph seemed normal, but when close-up views were taken of one suspicious area, a small but very significant abnormality was visible. She had fractured one of the bones of her spine. A wedge of bone had broken off the base of one of her vertebrae, the cube-like bones that make up the spinal column. Despite this fracture, she had been lucky, and the alignment of her spine had not been disturbed.

The spinal cord carries the nerve supply to the rear half of the body, including the hind limbs. It travels down in the centre of the backbone, protected inside a narrow tunnel that is formed by the end-to-end positioning of the many small spinal bones, each containing a hole that lines up with the adjacent bones on either side. As you can imagine, if one of those bones is broken and moved out of alignment with the other bones, the spinal cord in the tunnel is usually completely torn in half. This results in complete and permanent paralysis.

In Topsy’s case, one of the bones that makes up the wall of the tunnel had been broken, but it had not moved out of alignment. This meant that although her spinal cord had been damaged in the accident, there was a possibility that it might not have been completely severed. It may have been crushed, bruised and twisted, but it may not have been permanently damaged.

To evaluate the extent of her problem, I then carried out a detailed neurological examination was carried out. This involves systematically testing a tick list of reflexes and nerve function tests. The examination showed that Topsy had some movement in her right back leg, and she miaowed loudly when I pinched the toes of both back legs. This meant that, crucially, she still had sensation in her feet: her spinal cord was able to send messages from her back legs to her brain. This meant that although her spinal cord may have been damaged, it had not been torn in two: there was a chance that she could make a recovery.

When I returned Topsy to her cage, she dragged herself into her litter tray and passed urine on her own. This was an excellent sign, since it meant that her brain was able to send voluntary messages to her bladder. It was another sign of continued functioning of at least part of her spinal cord.

At this stage, there a ninety per cent probability that Topsy would improve with simple rest and time. If we could confine her to a cage for several weeks, there was a good chance that the broken piece of bone in her back would gradually weld back into place, without the need for surgery. We would need to monitor her nerve function very carefully, but with continued luck, Topsy would be walking again within a month.

If there had been no feeling in Topsy’s toes, and if she had not been able to pass urine, the picture would have been much bleaker. She would have had to be referred to a specialist centre for MRI scans and possible complex surgery, and even then, the chance of a full recovery would not have been high.

As it was, Topsy went home in a large cage that will be her home until she is better. One week into her recovery, she is already using both back legs. She is unlikely to have such a serious accident again, but if she does, her owners have made sure of one thing. They have taken out pet insurance for her, so that if she’s less lucky next time, the high costs of specialist referral work will be covered. Hopefully, it won’t be needed: one serious road accident in a lifetime is more than enough for any cat.