Is your older cat losing weight?

      Middle-aged to older cats may have weight loss that is so slow and subtle that owners are unaware of its occurrence.  Sometimes weight loss is so drastic that a cat may lose 20% of its body weight within a few months.  Whether fast or slow, your pet’s weight loss should be evaluated by your veterinarian.  Occasionally, owners will mistakenly attribute weight loss to “aging” when in reality there are three fairly common conditions of the older feline that are diagnosable and treatable.  Your kitty will certainly benefit from early diagnosis if he or she has any of these conditions.

    The three main weight loss diseases of older cats are: 1) hyperthyroidism, 2) diabetes mellitus, and 3) chronic renal failure.  In addition to weight loss these problems can cause changes in thirst, appetite, or volume of urination.                                 

                                               1. Hyperthyroidism

       Feline hyperthyroidism occurs in middle-aged to older cats with an average age reported to be 12-13 years.  In more than 90% of cats with hyperthyroidism, your veterinarian will be able to detect an enlargement of one or both thyroid lobes in the neck of your cat during a complete physical examination.  It is this enlarging organ that overproduces thyroid hormones with potentially devastating effects.  Thyroid hormones stimulate organs and metabolic processes throughout the body. The increased metabolic rate and heat production cause increased appetite, weight loss, muscle wasting, and weakness.  Often the cat will look unthrifty and the nails grow thick and fast.  Some cats are restless and more vocal than usual, others are lethargic.  Blood pressure may be elevated.  The pounding, overactive heart is at great risk of arrhythmia, murmurs, and failure if hyperthyroidism is left untreated.  Ultrasound of the heart is the best way to see how the heart has been affected.            

         Hyperthyroidism can be cured by surgery to remove the thyroid gland or radio iodine I-131 injection to destroy the abnormal gland.  Some patients who are not good surgical candidates may have their signs controlled with oral medication given twice daily.  Heart and blood pressure abnormalities may require additional medications.   

                                              2. Diabetes Mellitus

      Diabetes mellitus occurs when there is a deficiency of insulin.  Insulin is a hormone made in the pancreas that circulates through the body helping glucose (sugar) be used by muscle, fat, and liver tissue.  In a diabetic cat, glucose accumulates in the blood (hyperglycemia) and spills into the urine (glucosuria).  But the diabetic’s tissues are unable to efficiently utilize and transport the glucose into the cells and the cells and tissues literally starve for sugar in spite of high blood sugar.  The main signs you will see as an owner if your cat develops diabetes are increased thirst, urination, and appetite, with weight loss.  If these signs are ignored, the body may progress into a very dangerous ketoacidotic state due to the last resort  breakdown of fatty acid into ketone for energy.  Obese cats are at increased risk of developing diabetes.

     Diabetic kitties are usually treated with insulin injections and diet change.  Some, about 25%-30%, may be controlled with oral hypoglycemic medications and diet. Diabetes in cats cannot be cured but can usually be controlled by capable and willing owners.