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My cat is losing weight................

This is such a commonly heard phrase when older cats are brought into the vets. Sadly, many people delay these visits as they assume their much loved cat has cancer and the outlook is hopeless. This is not the case, and many diseases that cause weight loss can be managed to give a good quality of life into old age.

Kidney Disease: This is unfortunately very commonly seen in old cats, and can be linked to other problems too. Cats with kidney disease often drink and urinate more than they used too. With time, they can become picky with food, and start to groom less, so their coats can become matted. Kidney disease is easily diagnosed using a blood and urine sample. Cats generally do not mind these samples being collected, and the process usually takes just a few minutes. We cannot reverse the destruction within the kidneys, so it is important to make the diagnosis before too much damage occurs. Most commonly this problem is managed by changing the cat’s diet. The kidneys need to break down all the protein that is eaten, so favourite cat treats like chicken and fish will make the kidneys have to work harder and wear out faster. The prescription diets for kidney disease are low in protein to keep the kidneys functioning for longer. These diets are also lower in other salts, like phosphates, which the kidneys can’t properly get rid of when functioning poorly. These salts make cats feel nauseous and lethargic, so cats eating less of these salts tend to feel well for much longer. There are also drugs that can be used when needed- for example, cats with kidney disease are prone to cystitis and may need antibiotics from time to time. Some lose protein through their urine, and some have high blood pressure due to the kidneys, all manageable problems.

Gastrointestinal disease: It is thought that over 60% of cats have chronic intestinal disease, and some cats are more likely to show symptoms as they get older. These cats have thickening through their bowels which affects their ability to digest and absorb food. Despite eating well, they lose weight because they cannot use the nutrients properly. Some cats will vomit more regularly than they used too (despite otherwise appearing well) and some will have softer faeces. Some cats feel nauseous at times- they are hungry and go up to their food, but then seem reluctant to eat or stop eating after only a few mouthfuls. Some of these cats simply need a change of diet- there are several easily digested foods available designed for cats with digestion problems. Speak to your vet if you have noticed these symptoms, as bowel thickening can be felt by a vet and an appropriate management plan discussed.

Thyroid Disease: This is another vey common cause of weight loss in older cats. About 20-30% of cats will develop an overactive thyroid, which speeds up their metabolism. Most of these cats have a ravenous appetite but lose weight despite it. Left untreated, thyroid disease can result in damage to the heart and kidneys. This disease is also easily diagnosed with a blood sample, usually with a urine check at the same time. It is readily treated using tablets or surgery, or a form of radioactive iodine. An iodine free food is suitable for some cats, and can be an option for those cats impossible to dose with tablets.

Whilst cancer is certainly seen in practice and never good news, there are other very common causes of weight loss in older cats. Please speak to your vet if your cat is losing weight, as there is likely to be something we can do to make your cat feel better for longer.

Lee-Ann Higgins MRCVS