Following on from our article a few weeks ago about obesity in pets I thought I would tell you about one of our lovely feline patients that came in to see us here at St Vincent’s with quite the opposite! Poor Nabi came to visit us as her owners were worried that she was losing weight.  We confirmed that she was lighter than usual and also identified that she had a very fast heart rate.  We decided to carry out some further blood tests in house. Due to her weight loss and age, there were a few different conditions that we wanted to rule out including kidney disease, diabetes and an overactive thyroid gland otherwise known as hyperthyroidism.  The blood test confirmed that poor Nabi was suffering from hyperthyroidism.

Hyperthyroidism is a very common condition that we see here at St Vincents in middle-aged – older cats.  Hyperthyroidism is caused by increased production of thyroid hormones from a benign tumour on the cat’s thyroid gland which can be found on the neck.  Thyroid hormone regulates many processes including the cat’s metabolic rate. Therefore if there is increased hormone, the metabolic processes speed up causing the cat to lose weight despite having an increased appetite.  Other signs may include increased thirst, poor coat, tummy upsets, restlessness and also increased heart rate.  Fortunately most cases of hyperthyroidism can be treated successfully. Hyperthyroidism is usually easy to diagnose by a blood test.  Sometimes in other cases where we are worried about complications or concurrent disease, we carry out other tests.  These may include urine tests, blood pressure measurement, and chest x-ray or ultrasound.

Once Nabi was diagnosed we had a chat with Nabi’s owners about the treatment options.  The most common treatment is lifelong daily medication to control the disease. Unfortunately treating the disease with medication does not cure the disease and we need to monitor the thyroid levels with a blood test every 3-6 months. Another option is removing the thyroid surgically and this can actually provide a cure.  However, this is not without risk and occasionally the signs of hyperthyroidism can recur if previously unaffected thyroid tissue becomes diseased. Another option is treatment with radioactive iodine.  This is a very safe and effective treatment and is curative.  It is a specialist procedure and is not widely available.  It involves a single injection of radioactive iodine under the skin.  The iodine is taken up by the abnormal thyroid tissue only, destroying the tissue.  Side effects are very rare.  The cats are hospitalised and isolated for a week or two after the procedure as their faeces and urine need careful handling as they are radioactive. Nabi’s owners chose to treat Nabi with radioactive iodine.  This is a specialist procedure and so Nabi was referred to the Royal Veterinary College in Hertfordshire.  We are pleased to report her treatment was very successful and she is now doing wonderfully well and has gained weight!

Weight loss is a common symptom of many conditions that develop in old age and we would always advise contacting the practice if you have any concerns about your pet’s health.

Katie Love is a veterinary surgeon at St Vincents Veterinary Surgery, an independent practice offering personal care for all your pets. Katie has a keen interest in feline medicine and can be contacted at the surgery if you have any concerns about your pet’s health.