Leonard Brothers Veterinary Centre in Whitchurch has announced their latest star patient.

Sidney the cat was heading for slimmer of the year – he had been on a very strict weight loss programme and had got down to his ideal weight. This was a great achievement and he was a far happier and healthier cat.

However this summer things seemed a bit different. His weight loss seemed to be continuing so he was now heading down below his ideal weight and he seemed a bit more subdued than normal.

Nicky Smith, practice manager, said: "He came in for a check up and he was very much on edge, not a happy boy. There were no real clues as to what was going on but his weight and behaviour changes prompted Andy to run a blood test.

"The next day the results were back and they confirmed that poor Sidney had very high levels of thyroid hormone in his blood due to an over-active thyroid."

Overactive thyroid (hyperthyroidism) is a common condition in older cats and the classic sign is usually weight loss in the face of a normal or increased appetite. Affected cats also often drink more water and often have behaviour changes making them hyperactive or more grumpy. Sidney certainly fitted the picture of a cat with an over-active thyroid.

"The good news is that an over-active thyroid is treatable," continued Nicky.

"We have several treatment options available ranging from tablet medication to surgery. A lot of our cats with over-active thyroids start on a course of tablets and then have an operation to remove the diseased thyroid glands.

"Another option for Sidney was radioactive treatment and as he was a relatively young cat we decided to go down this route." Sidney started seeing the vets at “The Hyperthyroid Cat Centre” in West Yorkshire.

He passed all their initial tests and was booked in for his radioactive injection. The treatment involves a small injection of radioactive iodine. This iodine accumulates in Sidney’s thyroid gland and as it is radioactive it destroys the tissues. It is a very safe way to remove the diseased thyroid tissue without any major risks. The slight problem is that once Sidney has had his radioactive injection he was too radioactive to be safely handled for a week or so. He stayed over in Yorkshire in his solitary confinement but was happy and healthy throughout. He is now back at home and his weight and temperament have returned to normal and all of his test results are perfect, showing that the treatment has been a great success without complication.

Sidney’s case highlights a few issues – Don’t ignore changes to your pet’s weight. We will weigh your pet every time they come to see us and so should be able to pick up any worrying trends - even subtle signs of a behaviour change can be significant, so again don’t ignore them. Even severe problems like over-active thyroid can be treated very successfully so don’t assume that your cat is just getting old, there may be a problem which can be cured.