Can Cats Get Diabetes?

1 Overview

Diabetes splits into type 1 and type 2: type 1 is damaged islet function, unable to secrete insulin, dependent on external insulin – also called insulin-dependent diabetes.

Type 2 mostly shows insulin resistance, or both impaired secretion and resistance.

Among dog/cat diabetes, nearly 100% of dogs and 50% of cats are type 1; the other 50% of cats are type 2.

If insulin weakens for some reason, glucose that should enter cells stays in blood, raising blood sugar. This is hyperglycemia; if long-lasting, it damages the whole body.

Dog/cat diabetes incidence is 0.2%-1%.

2. Main symptoms of cat diabetes

Drinks a lot of water

Strong appetite

Weight loss, thinning, and dehydration

Increased amount and frequency of urination

Swollen belly (enlarged liver)

Cataracts

Diabetic ketoacidosis

Early on, symptoms are vague – just strong appetite, much water, much urine, but soon weight loss, thinning, dehydration. As it worsens: poor appetite, lethargy, weakness, unsteady walk; further: thin skin easy to injure, jaundice, coma, acute inflammation. If seen, see a vet at once to avoid worsening; left alone it is life-threatening.

On blood sugar levels, the line between healthy and diabetic cats is vague; the common reference is diabetes = 171-290 mg/dL.

Per a 2017 University of Queensland study, if a normal-weight cat aged 8+ has a blood sugar of 189 mg/dL or higher at the clinic, and 116 mg/dL or higher 3-4 hours later after stress drops, it is very likely diabetic. Recommend sending the cat to the hospital 18-24 hours before testing, then check fasting glucose and glucose tolerance.

In another past study, if fasting glucose is 135-151 mg/dL, there is a 75% chance of diabetes within 9 months; with a glucose tolerance test (0.5 g/kg IV glucose, measure at 2 hours), moderate intolerance means 38% chance within 9 months. But such levels and tolerance are only hints at diagnosis, judged with clinical signs.

Causes of cat diabetes

1. Eating too fast for too long

If a cat eats fast habitually, each meal releases much insulin. Then each cell reacts poorly to insulin, and glucose uptake weakens. Result: high blood sugar, eventually diabetes.

2. Age

Cat diabetes usually affects cats over 10. A 2016 UK large study confirmed incidence rises sharply from age 6. Here is Anicom Sompo’s 2012 cat diabetes stats, again confirming the sudden rise at 6. By gender, males 70%, females 30% – males dominate.

3. Primary disease

Pancreas inflammation and tumors can cause diabetes. Other diseases raising insulin resistance (poor response) include hyperthyroidism, acromegaly (90% male cats), Cushing’s (60% female), kidney disease, liver disease, heart failure, tumors, etc.

4. Drugs

Corticosteroids, luteinizing hormone, diuretics, heart drugs, anticonvulsants weaken insulin and cause diabetes.

5. Obesity

A 2016 UK large study found a link between weight gain and diabetes incidence. Specifically, setting rate at under 3 kg = 1, then 4.0-4.9 kg jumps to 3.2x, 5.0-5.9 kg to 5.1x, and 8.0 kg+ to 20x. The mechanism is thought: obesity-caused chronic inflammation of fat cells – increased/decreased adipokines – changed insulin resistance – diabetes.

By the way, adipokines are the general name for physiological substances made and secreted by fat cells.

6. Breed/genetics

Studies in UK, Europe, Australia show Burmese cats have high incidence. A Swedish study reports Norwegian Forest, Russian Blue, Abyssinian higher, Persian lower. Also a 2016 UK large study: Burmese (3x standard), Norwegian Forest (3.5x). From this, some breeds are clearly more likely.

Though no gene is confirmed linked, a study of obese cats suggests a mutation in the melanocortin-4 receptor gene (SNP) may relate to onset. And since most cat diabetes is type 2, the about 70 gene mutations behind human type 2 are thought shared, but details unknown.

Treatment of cat diabetes

1. Insulin plus glucose-lowering drugs

Subcutaneous injection of man-made insulin, done under vet guidance.

Do not overdo insulin. Dose strictly per vet; if too high, may cause hypoglycemia – loss of consciousness or convulsions; if insufficient, blood sugar won’t drop enough and the shot loses meaning. Proper dose depends on the day’s exercise and calories.

2. Fluid therapy

Multi-ion balance fluid, correct electrolytes and dehydration. Avoid lactated Ringer and glucose – they burden the liver, speed fat deposition, worsen glucose tolerance and blood sugar. Need potassium, phosphorus, magnesium supplements, slowly.

3. Food therapy

If the cat eats too much, blood sugar released rises, so consider meal quality and amount. Set daily calories, meal count, timing, and exercise.

Limit chemical carbs, raise protein – e.g., lean meat, eggs. Add needed vitamins/minerals, boost appetite.

4. Exercise therapy

Exercise can reduce excess fat or burn excess blood sugar. But forcing a cat to exercise may stress it into hyperglycemia. Combined with insulin, the dose changes with the day’s exercise.

The dose will vary with that day’s exercise amount.

Treating diabetes is long-term; a cat may need insulin for life. It takes great responsibility and love from the owner; the owner’s persistence is the cat’s hope.