Cats: Diagnosis and treatment of diabetes mellitus

Treating uncomplicated diabetes

Starting regulation

Two types of patients can be categorized as uncomplicated:

  1. Cats presented after the owner notes the appearance of clinical signs without general deterioration or diabetic ketoacidosis (DKA). These are non-emergency cases.
  2. Cats that have stabilized after initial presentation with and successful treatment for DKA.

During consultation:

  • Perform a thorough examination and weigh the patient.
  • Evaluate laboratory test results including complete blood count, urinalysis (including sediment examination), and serum biochemistry profile (including T4).
  • Photograph patient’s head and whole body; optional but often the only way to diagnose subsequent acromegaly.
  • Rule out hyperthyroidism, renal failure, inflammatory bowel disease, pancreatitis and exocrine pancreatic insufficiency, hyperadrenocorticism, acromegaly, neoplasia, or hepatic disease.

When health status is known and diabetes mellitus confirmed:

  • Thoroughly explain to pet owner what diabetes mellitus is, that achieving regulation may take up to 2 months, and what the implications are for the family. Make sure the owner understands the treatment involved, and that the cat should be able to live a happy, healthy life with consistent treatment. This is crucial, as complete cooperation of the owner is essential to treatment success.
  • Treat existing infections or other medical conditions. Any disease will affect insulin metabolism.
  • Introduce appropriate diet.
  • Begin treatment with Vetsulin® (porcine insulin zinc suspension).

Starting Vetsulin

In-clinic:

  • Weigh the cat to obtain a benchmark for future weight gain or loss.
  • Start the cat on 1 to 2 IU injections of Vetsulin given twice daily at 12-hour intervals. Administer injections concurrently with or right after meals for cats fed twice daily. No change in feeding schedule is needed for cats fed ad libitum.
  • Hospitalize the cat for the day to verify that the starting dose does not cause hypoglycemia.
  • Instruct owner on:
    • How to administer injections
    • How to identify and treat hypoglycemia
    • Parameters to monitor at home
    • Preferred diet and frequency of meals
  • Discharge cat to owner’s care for 2 to 4 weeks. This allows the cat and owner to acclimate to the injection regimen.

At home, have the owner:

  • Monitor and record water and food consumption.
  • Monitor and record urine glucose and/or ketone bodies.
  • Maintain starting dose and frequency of administration for 1 to 2 weeks, unless there’s evidence of hypoglycemia.
  • Bring the cat in for re-evaluation 2 to 4 weeks after starting Vetsulin treatment.

In-clinic re-evaluation:

  • Verify adequate injection technique.
  • Evaluate owner's monitoring of clinical signs and glycosuria.
  • Weigh the patient.
  • Evaluate glycemia via glucose curve or punctual blood glucose evaluations.
  • Increase insulin dose if necessary, according to clinical signs and glycemia values. An interval of 2 to 4 weeks between dosage increments is ideal (unless there’s evidence of hypoglycemia).

Regulation:

  • Repeat procedures listed above at regular intervals until clinical signs and weight are satisfactory.
  • When regulation is achieved (no clinical signs; satisfied owners), schedule rechecks every 2 to 4 months:
    • Perform a complete physical examination
    • Revise home monitoring if necessary
    • Evaluate glycemia if necessary (eg, glucose curve, fructosamine, etc.)

If there is a problem:

If clinical signs resume, fructosamine levels are not satisfactory, or overall health deteriorates, causes must be identified.

  • Perform a complete physical exam.
  • Recheck:
    • Injection technique and insulin quality control
    • Feeding and exercise
    • Environment of the patient (recent changes)
  • Perform a glucose curve.
  • Evaluate complete blood count, urinalysis (including sediment examination), and serum biochemistry profile (including T4).
  • Additional testing procedures may be required. Diabetic cats may develop other concurrent diseases or infections that will interfere with insulin.