Fruit Valley Veterinary Clinic

Management of the Diabetic Cat

Modified from The compendium on Continuing Education

Your cat has a disease called diabetes mellitus in which your pet does not have enough natural insulin to maintain normal body function. Consequently, you must provide the insulin by daily injection.

At your pharmacy, you will purchase Lantus (glargine)(100 units per ml); 1/3cc insulin syringes(100-unit with 1/2 inch needles) with the accompanying prescriptions. Insulin should be refrigerated at all times and the bottle must be rolled gently prior to withdrawal of the insulin into the syringe. The injection must be given subcutaneously (beneath the skin). Your doctor will demonstrate the correct injection technique.

The amount of insulin required each day may be subject to change depending on various factors such as alterations in diet, exercise, and certain environmental stresses. The dose of insulin is calculated by determining the amount of sugar in your pet’s urine or blood levels each morning prior to insulin administration. To measure urine sugar or blood, you will purchase an Alphatrak (on line) ( for blood),or a box of Keto-Diastix (for urine) from your pharmacy. The instructions for the Keto-Diastix are simple to follow but you will need a urine sample. Unless otherwise directed by your doctor, the following protocol should be followed:

  1. First thing in the morning, obtain a urine or blood sample and determine the amount of sugar OR observe cat for signs of weakness, vomiting hunger or thirst.
  2. Feed your pet 25% of its usual total daily food intake.
  3. Administer the insulin dose subcutaneously.
  4. A few hours later feed another 25%
  5. 12 hours later repeat steps 2 to 4. Many cats only need once-a-day insulin so that step 3 would be skipped.
  6. Collect another urine or blood sample when you expect it to have the lowest sugar reading.

Ketones should always be negative (a urine measurement).

Schedule an appointment or try to talk to a vet if ketones show up.

It is desirable to have some sugar showing up in the urine, but not 2% or more

The dose should be decreased immediately if your cat is vomiting or not eating.

The insulin dose ONLY needs to be increased if ALL measurements, taken throughout the day are high (2%) for at least three days. If your cat is not losing weight and acting fine, and has no ketones, then the sugar can also be decreased by feeding a little less rather than increasing the insulin. Do not do both at the same time (Do not increase insulin plus decrease food on the same day. All changes except for decreasing insulin if vomiting or not eating should be gradual small changes)

For a Cat: Use the lowest reading of all measurements

If urine sugar is 4+ (2%)..................................... Increase 1/2 unit over previous dose

If urine sugar is 3+ (1% )..................................... Increase 1/2 unit over previous dose or repeat previous dose or decrease food a little

If urine sugar is 2+ (1/2%).................................. Repeat previous dose

If urine sugar is trace (1/10% or 1+ (1/4%)...... Repeat previous dose

If urine sugar is negative ..................................... Decrease 1/2 or 1 units from previous dose or repeat previous dose

The ultimate objective is to maintain the morning urine sugar at trace to 2+ level, to maintain a reasonable weight, to keep the urine ketones negative and to help your cat not be excessively thirsty.

Infrequently your pet may experience an insulin reaction due to marked decrease in its blood sugar. The signs accompanying such a reaction will mimic a drunken state: your pet will be weak and walk with a wobbly uncoordinated gait. Should this occur, administer Karo Syrup orally (approximately 1 tablespoon for a 10 pound cat but give in small amounts to be absorbed through the gums if trouble swallowing) If no improvement is seen after 15 minutes or if the signs worsen, come to the hospital immediately for emergency treatment. CALL FIRST!! (343-4300)

Dietary changes can help diabetic control. Discuss with your veterinarian.

Should your cat ever become ill or experience any type of trauma, your veterinarian should be contacted immediately.

Problems Frequently Encountered

  1. If you attempt to give the morning injection and your pet gets only part of its dose due to sudden movement causing slipping of the needle under the skin, do not attempt to deliver the lost amount by giving another injection. Simply wait until the next dose and give as normal.
  2. If your pet is unable to eat after insulin is given (for example, if it is vomiting) try to administer a semiliquid diet such as baby food. If vomiting persists, contact your veterinarian immediately.
  3. If you have a female pet, we strongly urge that she be spayed prior to her next heat since loss of diabetic control occurs during the heat period.

If any problems or questions arise, please call your veterinarian

Examples of adjusting dose and monitoring:

1. My cat has been getting 2 units once a day for months. She does not urinate much now, so I can never get a urine sample. She is acting fine, not losing any weight, so I have not bought an AlphaTrak. She vomited overnight and did not eat this morning, so I did not give her any insulin. She is now very thirsty. When she urinated, it had 2% sugar and no ketones. I gave her just 1 unit of insulin so that if she does well overnight we can return to our usual routine.


  1. No insulin when vomiting, not hungry or not thirsty
  2. Some insulin (1/2 dose) when thirsty, sugar in urine but still at risk of vomiting (not very hungry yet either)

2. My cat was sent home on 2 units once a day but for the past 2 weeks the urine glucose is 2%, ketones negative but he is losing weight, very hungry and very thirsty. I can only collect a urine sample first thing in the morning by cleaning out the litter box, giving him some water to drink and waiting about 10 minutes with a lid to catch a few drops of urine. I have also tested his urine by pressing the strip against fresh wet litter and get the same readings, but I raised his dose to 2.5 units and he stopped losing weight and stopped drinking so much, but his morning urine glucose is still 2%.


  1. Make a small increase in insulin if many persistent signs of diabetes: weight loss, excessive thirst, excessive hunger, high sugar in the urine
  2. Keep the insulin dose the same if few/no symptoms of diabetes despite the high sugar reading. If any signs of excessive insulin such as acting disorientated or propulsive, weak or wobbly the dose would need to be lowered.